Thioredoxins play critical roles in the maintenance of cellular redox homeostasis by regulating the structure and function of the target proteins through catalyzing thiol-disulfide exchange reactions. Previous research has confirmed that the y-type thioredoxin HbTRXy2 of rubber tree (Hevea brasiliensis) has a strong antioxidant function. To investigate the molecular mechanism of HbTRXy2 in enhancing antioxidant defense, a yeast two-hybrid library of rubber tree and the bait vector pGBKT7-HbTRXy2 for HbTRXy2 were constructed, and the interacting proteins of HbTRXy2 were identified via yeast two-hybrid in this study. The results indicated that the secondary library constructed in this study had a recombination rate of 100%, an average length of inserted fragments greater than 1000 bp, and a capacity of approximately 3.80×10⁶ CFU/mL. It was identified that the bait vector has no toxicity and self-activating activity in yeast and could be used for yeast two-hybrid screening. After testing, it was found that the bait vector had no toxicity and self-activating activity in yeast and could be used for yeast two-hybrid screening. Using the co-transformation method, 24 proteins interacting with HbTRXy2 were screened from the constructed library. Bioinformatics analysis revealed that the functions of the candidate interacting proteins encompassed redox processes, stress responses, ATP binding and metabolism, Calvin cycle, single-carbon metabolism, carbon fixation, methionine biosynthesis, lipid A biosynthesis, metal ion binding or transport, transmembrane transport, cell volume regulation, phosphate ion homeostasis, protein phosphorylation, protein folding, etc. The results would lay the foundation for further revealing the function and mechanism of HbTRXy2 in rubber tree.

Natural rubber is a key and widely used industrial raw material, which is mainly produced from Hevea brasiliensis. Cis-prenyltransferase (CPT) is an important component of natural rubber biosynthesis in laticiferous cells. It has been reported that HbCPT7 and HbCPT8 are specifically and highly expressed in latex, which is the cytoplasm of laticifers, and HblMYB19 and HblMYB44 can significantly promote the expression of HbCPT8 in tobacco and yeast. However, the transcription factors that regulate the specific expression of HbCPT7 in latex are still not clear. Here, we found there are several MYB- and MYC-binding sites located in promoter region of HbCPT7. We totally identified 226 HbMYBs and 19 HbMYCs in Hevea by using a genome-wide scanning approach. The transcriptome data showed that HbMYB1, HbMYB2, HbMYC1, HbMYC2, HbMYC3, HbMYC4 and HbMYC5 were highly expressed in latex. HbMYB1, HbMYB2, HbMYC1, HbMYC4 and HbMYC5 were successfully cloned from the latex of rubber trees. Through yeast one-hybrid assays, it was discovered that HbMYC5 could bind to the promoter regions of 1–1000 bp and 1501–1971 bp upstream of the start codon of HbCPT7. The results would provide a new insight into the molecular mechanism of HbCPT7 in regulating natural rubber biosynthesis.

Cassava (Manihot esculenta Crantz), the “king of starch”, is an important tropical food crop and a staple food for one billion people worldwide. Cassava vacuolar invertase (MeVINV1) is involved in plant growth and development and stress defense by irreversibly breaking down sucrose into glucose and fructose. Eight candidate proteins interacting with MeVINV1 were screened from the cassava SC8 cDNA yeast library by yeast two-hybrid experiment to explore the gene function and molecular regulatory network of MeVINV1. Furthermore, yeast point-to-point verification found that MeVINV1 interacted with MeUN-3, MeMTP1, MeCASP4A3 and MePIRL3, and the interaction with MeMTP1 was stronger. Therefore, it is speculated that MeVINV1 and MeMTP1 synergistically regulate vacuolar sucrose metabolism and metal ion transport, and participate in the regulation of cassava response to metal ion stress. The results of the study would provide a scientific basis for providing new genetic resources and molecular mechanisms of stress regulation in cassava stress resistance breeding.

Polygalacturonase (PG) plays a crucial role in plant growth and development, and in stress responses, by participating in the degradation of pectin and altering cell wall structure. Although studies on PG genes have been conducted in various plants, there is a lack of research on the identification and functional characterization of the PG gene family in cassava (Manihot esculenta Crantz). This study identified a total of 89 members of the MePG family in the cassava genome, encoding proteins with 183 to 808 amino acids, molecular weights ranging from 19.75 to 87.07 kDa, and theoretical pI values between 4.64 and 9.71. Most of the family members are predicted to be localized in the cell membrane. Chromosome mapping analysis revealed that MePG family members were unevenly distributed across 17 chromosomes. Based on evolutionary relationships, MePGs were classified into seven subgroups (A to G), with similar gene structures within subgroups and evidence of tandem duplication. Comparative analysis indicated that the PG family genes in cassava were more closely related to rubber than to Arabidopsis. The promoter regions of MePG genes were enriched with elements responsive to light, hormones, and stress. MePG genes exhibit tissue specificity and were associated with cassava growth and development. During postharvest deterioration of cassava, MePGs displayed similar expression patterns, particularly MePG20, MePG21, MePG25, MePG64 and MePG72, which showed an initial increase followed by a decrease in expression, suggesting that the genes may initially respond to stress, upregulate to break down pectin, and then downregulate as cell wall hydrolysis is completed. This implies a significant role for PG in stress responses. Collectively, the findings suggest that MePG gene family members may have evolved through segmental duplication and intron loss and may perform different functions by sensing various types of signals, leading to diverse expression patterns. This would study provide a foundation for further exploration of the role of MePGs in the postharvest deterioration mechanism of cassava roots.

Isoamylase (Isoamylase, ISA) catalyzes the hydrolysis of α-1,6 linkages, thereby affecting the branching structure of starch and promoting crystallization and granule formation. The study utilized yeast two-hybrid screening to identify proteins interacting with MeISA2 to explore new proteins that may interact with MeISA2 to influence cassava starch accumulation. A bait protein vector pGBKT7-MeISA2 was constructed, and it was demonstrated that MeISA2 did not possess autoactivation activity and was non-toxic to yeast cells. Through yeast two-hybrid screening of a cDNA library, a total of 7 candidate interacting proteins were obtained. Point-to-point yeast two-hybrid re-validation experiments confirmed the interaction between MeISA2 and MePsbO1. MePsbO1 belongs to the Photosystem II oxygen-evolving enhancer protein (PsbO) family, which facilitates the efficient operation of the photosynthetic electron transfer process. Bioinformatics analysis revealed that MePsbO1 had the closest phylogenetic relationship with HbPsbO1 from Hevea brasiliensis, a member of the Euphorbiaceae family, with a similarity of 90.12%, while its similarity to Arabidopsis thaliana AtPsbO1 was only 77.71%. It is predicted that MePsbO1 is localized in the chloroplast, and the MePsbO1 gene is predominantly expressed in leaves. Plant ISA is involved in the synthesis of transient leaf starch, thus it is hypothesized that MePsbO1 and MeISA2 may interact to jointly regulate the rate of photosynthesis and the accumulation of transient leaf starch. The results study would provide new insights into the mechanism by which the MeISA2 gene participates in the accumulation and distribution of photosynthetic products in cassava source organs.

LEC2 is an important member of the LAV subfamily in the plant B3 superfamily and plays a significant regulatory role in embryo development and meristem maintenance. To explore the function of the PvoLEC2 in the cell regeneration of Plukenetia volubilis, the genomic sequence of PvoLEC2 (gPvoLEC2) was cloned through phylogenetic analysis and molecular biology techniques. The function of gPvoLEC2 in promoting plant regeneration was verified in Nicotiana benthamiana, and the function of gPvoLEC2 was studied in P. volubilis hairy roots. Phylogenetic and gene structure analysis indicated that the LEC2-ABI3 subfamily of Euphorbiaceae plants such as P. volubilis, and Arabidopsis thaliana, Oryza sativa, Populus spp. were relatively conserved. Expression analysis showed that PvoLEC2 was only weakly expressed in the late stage of P. volubilis seed development (50-65 DAP), and the motifs and key amino acid sites of the B3 domain were conserved. Overexpression of gPvoLEC2 led to dwarfing of transgenic N. benthamiana plants, difficulty in the growth of the main stem, and abnormal leaf development. At the same time, the regeneration ability of gPvoLEC2 transgenic N. benthamiana organs in vitro was significantly higher than that of the wild type, but lower than that of the positive control-ZmWUS2 & STM transgenic N. benthamiana. Overexpression of gPvoLEC2 in P. volubilis hairy roots led to their shortening and thickening. The results indicate that the genomic sequence of PvoLEC2 is a functional sequence that promotes plant regeneration, but it also causes abnormal development.

GASA (gibberellic acid-stimulated Arabidopsis) is a small molecule polypeptide widely presented in plants, playing an important role in plant growth and development processes. It has potential value especially in the regulation of mulberry bud dormancy. However, currently, the understanding of the functions of MaGASA genes in mulberry during the bud dormancy process is limited. The study aimed to identify the members of the mulberry GASA gene family and analyze the roles in bud dormancy. Bioinformatics methods were used to identify the members and analyze the physicochemical properties and other characteristics. Meanwhile, real-time fluorescence quantitative PCR and transcriptome data were utilized to analyze the expression patterns. The results showed that there were 12 MaGASA family members (MaGASA1-MaGASA12) in mulberry, which were distributed on eight chromosomes. There were differences in acidity and alkalinity among the members, and the average hydrophilicity coefficients were positive or negative, but all contained the GASA conserved domain. The phylogenetic tree showed that they had a close genetic relationship with peach. Collinearity analysis revealed that there were three collinear relationships in the MaGASA gene family. The promoter regions of MaGASAs contained cis-acting elements that respond to light, low temperature, and various hormones. The MaGASA family members showed tissue-variety specific expression. Among them, the expression level of MaGASA12 in mulberry buds was significantly higher than that in other parts. Transcriptome analysis indicated that the expression level of MaGASA12 decreased significantly during the dormancy breaking process, while the expression level of MaGASA10 increased sharply during the dormancy breaking process. The expression levels of MaGASA10 and MaGASA12 at different dormancy stages were detected by real-time fluorescence quantitative PCR technology, and the results further verified the conclusions of the transcriptome analysis, indicating that they may be related to the winter bud dormancy process of Morus. The research results would provide a theoretical reference for the in-depth study of the biological functions of MaGASA in mulberry and genetic breeding.

Stylosanthes guianensis, Pueraria phaseoloides, and Tephrosia candida were selected to investigate the impact mechanisms of green manures on soil physicochemical properties and nitrogen content in rubber tree leaves, through the analysis of natural abundance of ¹⁵N (δ¹⁵N) and partial least squares path analysis (PLS-PM) to elucidate the effects of different leguminous green manures on soil improvement and nitrogen uptake in young rubber plantations. Results showed that P. phaseoloides and S.guianensis treatments significantly increased soil alkaline nitrogen by 30.54% and 31.25%, respectively, while reducing available potassium by 8.40% and 6.87%, compared to natural grass cover. P. phaseoloides treatment had the strongest effect on increasing soil organic matter and available phosphorus content, with increases of 12.60% and 30.94%, respectively. S. guianensis treatment had the strongest effect on increasing the total nitrogen content in rubber trees leaves (an increase of 25.86%). Correlation analysis and PLS-PM indicated a significant positive correlation between leguminous green manures and soil alkaline nitrogen and total nitrogen content, with a significant positive effect. In conclusion, under the conditions of this study, leguminous green manures promoted the absorption and accumulation of nitrogen in rubber tree leaves by increasing soil alkaline nitrogen content. The rational selection or mixed planting of leguminous green manures can improve the nutrient absorption efficiency of rubber trees and contribute to the sustainable production of rubber plantations.

The influence of root exudates on neighboring plants is one of the important factors determining the coexistence status of plants and their neighbors. This study aimed to explore the effects of the root exudates of Stylosanthes guianensis and cultivation substrates on the growth and physiological characteristics of Hevea brasiliensis seedlings. We cultivated H. brasiliensis seedlings with distilled water, sterilized vermiculite, and soil as cultivation substrates, and compared the differences in biomass accumulation and distribution, aboveground and underground morphological characteristics and physiological characteristics of H. brasiliensis when they respectively were irrigated with nutrient solutions containing the root exudates of S. guianensis and containing their own root exudates. The results showed that in soil culture and distilled water culture, the aboveground biomass, underground biomass, total biomass, primary lateral root number, chlorophyll content, carotenoid content, soluble carbohydrate content and root vitality of H. brasiliensis seedlings under the treatment of S. guianensis root exudates were significantly higher than those under the treatment of their own root exudate (P<0.05), except for the difference of root-shoot ratio, plant height and root length. Moreover, except for root vitality, the increase extent of the indexes was distilled water culture > soil culture. The malondialdehyde (MDA) content of S. guianensis root exudate treatment was significantly lower than that of H. brasiliensis root exudate treatment (P<0.05). When cultured with sterilized vermiculite, there were no significant differences in biomass index, morphological index and MDA content of H. brasiliensis seedlings treated with root exudates of two kinds of plants, but chlorophyll content, carotenoid content, soluble sugar content, and root vitality were significantly increased under root exudates of S. guianensis treatment (P<0.05). The comprehensive evaluation of membership function of H. brasiliensis seedlings cultivated in the substrates under the treatment of root exudates of S. guianensis was higher than that of their own root exudates, and the comprehensive evaluation of cultivation substrates under the treatment of the same root exudates was vermiculite culture > distilled water culture > soil culture. It indicates that the root exudates of S. guianensis can significantly improve the physiological function of H. brasiliensis seedlings and promote their growth, but the response of H. brasiliensiss to root exudates is significantly affected by the cultivation substrate.

After intercropping pepper with areca nut, pepper plants recovered their growth. This might be related to the mutual interaction between the rhizospheres of the two plants, especially the promoting effect of areca nut root exudates on pepper plants. However, the specific components that play a role remain unclear, which makes it difficult to provide a basis for in-depth research. In this study, the root exudates of pepper and areca nut seedlings were extracted by hydroponics. The full components of the root exudates were identified by LC-MS/MS metabolomics, and the specific differential components unique to areca nut root exudates were screened out. After classification, these were used as the exogenous substances and added to further clarify the effects of different components on pepper seed germination and seedling growth. A total of 426 metabolites were detected in the root exudates of pepper, and 438 metabolites were identified in those of areca nut. There were 509 differential metabolites between areca nut and pepper, among which 329 were significantly different, and 138 were more abundant in areca nut and 191 in pepper. The contents of flavonoids and organic acids were higher in areca nut root exudates than those in pepper, while the contents of sugars, phenolic acids, coumarins, benzoic acids and amino acids were higher in pepper than in areca nut. After classification of the differential metabolites with high content in areca nut root exudates into organic acids, amino acids, phenolic acids, sugars and flavonoids, two with higher fold differences were selected as specific components for addition. The results showed that the addition of flavonoids had the highest germination rate and germination potential of pepper seeds, and the height of seedlings, dry weight of aboveground and underground parts were the highest. The addition of organic acids and phenolic acids was second, while the effects of sugars and amino acids were not obvious. In conclusion, there are many specific differential components in areca nut root exudates, but the promoting effects of different components on the growth of pepper seedlings in soil culture after intercropping are different. Among them, the flavonoids group has a large number and high content, and has obvious promoting effects on pepper seed germination and seedling growth, which is the main component of areca nut root exudates that alleviates the disorder of pepper intercropping. The results of this study provides a basis and theoretical evidence for revealing the mechanism of rhizosphere interaction between the two plants and analyzing the alleviation of pepper intercropping disorder by intercropping with areca nut.

The browning of the fruit pericarp is one of the most significant quality deterioration characteristics of litchi during storage, transportation, and circulation after harvest, which seriously affects its commercial value. In this study, three stress treatments were applied to litchi, mild dehydration treatment (DT), heat shock treatment (HT), and cold shock treatment (CT). We analyzed the changes in appearance quality, browning index, physiological indices, and the activities of polyphenol oxidase (PPO), peroxidase (POD), and superoxide dismutase (SOD) after treatment to explore a new approach to delay pericarp browning by inducing resistance in litchi. The results indicated that after the three stress treatments, the browning of the litchi pericarp was exacerbated, accompanied by a decrease in pericarp brightness, water content, and increased membrane permeability at room temperature. The browning in the DT group was the most rapid, reaching a browning index of 4.99 on the 6th day. In contrast, HT and CT significantly delayed the browning of the litchi pericarp. The completely browned pericarp in the DT group was dry, yellow, and brittle, with the lowest water content (27.76%), which was significantly lower than that in the HT and CT groups (45.20% and 42.99%, respectively). The order of respiration rates was CT>HT>DT, and the relative electrical conductivity was DT>HT>CT. The activity of PPO and POD in the HT and CT groups was inhibited during the early part of storage, while the activity of SOD significantly increased at the later stage. Transmission electron microscopy results showed that the cell structure of the brown peel was destroyed and the contents were largely degraded in the DT and CT groups, whereas the brown pericarp cells in the HT group remained structurally intact and contained a large amount of coalesced sediments. Correlation analysis results showed that the browning index of the litchi pericarp under the three stress treatments was positively correlated with relative conductivity and negatively correlated with L^* (brightness), water content in the pericarp, and anthocyanin content (P<0.05). In conclusion, mild dehydration treatment led to rapid browning of litchi, while heat shock and cold shock stress treatments maintained higher water content in the pericarp and respiratory intensity of the litchi fruit. The treatments inhibited the increase of relative electrical conductivity and the activities of PPO and POD enzymes and increased the activity of SOD in the later storage period by stimulating the litchi’s self-resistance, thereby inhibiting the browning of litchi fruits and delaying the decline in fruit quality.

Coffee is an important economic crop in Yunnan, China. To investigate the effects of bee pollination on coffee production, this study examined the species of pollinating bees and the foraging behavior of dominant bee species during the coffee flowering period in Lisou, Ximeng, Yunnan. Additionally, the study evaluated and compared the fruit traits of coffee under bee pollination and control groups. The results showed that the bee species visiting coffee flowers included Apis dorsata, Apis cerana cerana, Apis florea and bumblebees (Bombus spp.), with A. dorsata and A. cerana cerana being the dominant species. A. dorsata visited coffee flowers throughout the day (from 9: 00 to 17: 00), while A. cerana cerana primarily foraged in the morning. However, the visiting duration per flower of A. cerana cerana was extremely significantly longer than that of A. dorsata (P<0.01). Introducing A. cerana cerana colonies increased the number of flower-visiting bees. Compared with the control group, the bee pollination group showed significantly higher fruit set rates, single fruit weight, seed weight, and seed number. Moreover, the fruit skins became thinner, and other traits improved, with a higher proportion of fruits reaching high maturity at harvest. The findings suggest that bee pollination can significantly improve coffee fruit traits, promote fruit maturation, and effectively enhance coffee quality. The results would provide a theoretical basis for improving coffee cultivation and productivity.

External application of regulator can reduce the damage of plants under low temperature stress, and 2,4-epibrassinolide (EBR) is a regulator that can enhance the cold resistance of plants. The study was aimed to investigate the influences of exogenous 2,4-epibrassinolide on the physiological characteristics of Dendrobium hybrida seedlings under low-temperature stress. In this study, the seedlings of Dendrobium hybrida ‘Sweel Maple’ were treated with various concentrations of EBR solutions (0, 0.1, 0.5, 1.0, 1.5, 2.0 mg/L) through foliar spraying, and then treated under 5 ℃ low-temperature in artificial climate chamber. The yellowing leaf rate, defoliation rate and the malondialdehyde (MDA), soluble sugar, soluble protein, proline and chlorophyll content of treated samples were measured. The results indicated that EBR could significantly reduce the rates of yellow leaves and defoliation in D. hybrida seedlings under temperature stress, with the optimal treatment concentration being 2.0 mg/L. Compared with the control, the rate of 50% yellow leaves, 100% yellow leaves, and defoliation decreased by 27.41%, 16.55% and 20.64%, respectively. Additionally, 2.0 mg/L EBR effectively mitigated the decline in chlorophyll content in seedlings’ leaves under low-temperature stress and decreased the relative electrical conductivity and MDA content. Specifically, the relative electrical conductivity decreased by 14.33% and the MDA content by 29.03%, compared to the control. Furthermore, 2.0 mg/L EBR enhanced the content of osmotic adjustment substances in the seedlings’ leaves under low-temperature stress. On the eighth day of stress, the soluble protein and soluble sugar contents reached 1.68 mg/mL and 46.49 mg/mL, respectively, while proline content peaked at 142.28 μg/mL on the second day after returning to normal temperature, which was significantly higher than that in the control. In summary, EBR effectively alleviated the damage caused by low-temperature stress to D. hybrida seedlings. Various indicators demonstrated that 2.0 mg/L EBR exhibited the most prominent effect in enhancing the seedlings’ cold resistance, making it the optimal treatment concentration.

The study was aimed to explore the photosynthetic characteristics and yield underground corm of Amorphophallus muelleri under different light conditions. Three intercrop modes of A. muelleri, pruned rubber tree intercrop mode T₁ [forest center (T_1M) and forest edge (T_1S)], interrow mode of puelia T₂[forest center (T_2M) and edge (T_2S)], 50% light transmittance shade mode T_3M, no pruning rubber tree (CK)[forest center (CK_M) and edge (CK_S)] were used. The light intensity (Lux) and photosynthetically active radiation (PAR) in different light conditions were measured. The daily variation pattern of A. muelleri, photosynthetic parameters [net photosynthetic rate (P_n), stomatal conductance (G_s), intercellular carbon dioxide concentration (C_i), transpiration rate (T_r)], chlorophyll fluorescence parameters [maximum photochemical efficiency (F_v/F_m), actual photochemical quantum yield(YII), maximum electron transfer rate (ETR_max), half-saturation light intensity (Ik)], photosynthetic pigment parameters [chlorophyll a (Chl a), chlorophyll b(Chl b), total chlorophyll (Chl a+b), chlorophyll a/b (Chl a/b)] were measured at three stages (head changing stage, corm expansion stage, maturity stage). The yield of underground corm under different light conditions was compared. The results showed that daily variations of Lux and PAR were basically consistent under light conditions, showing “unimodal”modes. There were significant differences in the photosynthetic parameters (P_n, G_s, T_r, and C_i) among different light conditions. Compared with CK, P_n, G_s, and T_r of the T_3M were the significantly highest in all three stages. During the head changing and corm expansion stages, P_n, G_s, T_r of the T₁ and T₂ were significantly higher than those of CK; The chlorophyll fluorescence parameters (F_v/F_m, YII, ETR_max, IK) of each light conditions were significantly higher than those of CK; The changes in photosynthetic pigment parameters (Chl a, Chl b, Chl a+b, Chl a/b) of various conditions were irregular. The Chl a, Chl b, Chl a+b of T₂ and CK were higher than those of T₁ and T₃ at all three stages, and Chl a/b of all treatments was significantly higher than those of CK. From the comparison of light intensity and yield between the forest center and edge under conditions, it can be seen that the forest center is higher than the forest edge. After comparing the implementation effects of various intercropping modes, it can be seen that all treatments have improved the photosynthetic characteristics and yield of A. muelleri, while the pruned rubber tree modes T₁ treatment is most obvious, and achieved the similar effect of single cropping under artificial shade. Therefore, in rubber tree production, pruning measures or other measures is needed to improve the light conditions and replace monoculture artificial shade for planting A. muelleri. The intercrop mode of puelia requires increase in fertilizer application and a reasonable allocation of crop distance direction to effectively alleviate the burns caused by direct sunlight on A. muelleri plants, and improve photosynthetic efficiency, thereby increasing crop yield and land use efficiency.

Nymphaea prolifera has a peculiar and unusual asexual reproductive mechanism called floral “vegetative viviparity” which allows it to produce new seedlings directly from its flowers. Understanding the formation process of floral vegetative viviparity and the effect of endogenous hormones on its formation will provide a basis for further elucidating the mechanism of vegetative viviparity in N. prolifera and the biology of asexual plant reproduction. Morphological observation, paraffin sectioning and scanning electron microscopy were used to analyse the morphological characteristics of vegetative viviparity flowers of N. prolifera as the test group and normal flowers as the control group. Elisa assay was used to compare the deviation in endogenous hormones between “nutrient propagules” from vegetative viviparity flowers and pistils from normal flowers. Nutrient propagules were formed on the receptacle in the original pistil area and are already formed at the stage of flower bud differentiation. In contrast to the flowers of normally developing water lilies, vegetative viviparity flowers only retained receptacle, sepals, and other organs; they lack petals, stamens, and pistils. Then, the nutrition propagules could continually develop leaf and flower buds. The leaf buds were mostly triangular and curled, while the flower buds were mostly hooked or conical and had many ciliated tissues on the surface. A vegetative viviparity growing flower's nutritional propagules could give rise to several asexually reproducing buds, which could then proceed to reproduce in a second and third generation once they reached a particular stage of development. Endogenous hormone assays showed that indoleacetic acid (IAA) and gibberellin (GA) levels were not significantly different between normal and vegetative viviparity water lily flower nutrient propagules, whereas jasmonic acid (JA), cytokinin (CTK) and abscisic acid (ABA) levels were systematically higher in vegetative viviparity water lily flower trophozoites. Vegetative viviparity flowers of N. prolifera had obvious differences in tissue structure compared to normal flowers. During flower bud differentiation, the gynoecium of N. prolifera flowers was replaced by the nutritive propagules to form vegetative viviparity flowers. Compared with those of the gynoecium of normal flowers, three endogenous hormones such as jasmonic acid (JA), cytokinin (CTK) and abscisic acid (ABA) levels were consistently higher in the nutritive propagules of vegetative viviparity flowers, which may contribute to the formation of the floral vegetative viviparity phenomenon.

Cibotium barometz, a nationally second-class protected plant in China, exhibits significant medicinal and ornamental value. It is naturally distributed in the southern regions of China and exhibits stringent requirements for its growth environment. Investigating the physiological response mechanisms of C. barometz to low-temperature stress can provide a scientific foundation for its artificial cultivation and the comprehensive development and utilization of its resources. This study utilized artificially cultivated C. barometz as the experimental material and established three temperature levels: 5 ℃, 15 ℃ and 25 ℃. Each temperature level was subjected to treatments lasting 5 days, 10 days, and 15 days, respectively. Following the stress treatment, chlorophyll fluorescence parameters, physiological indicators, and total flavonoid content in the leaves were measured. The growth and physiological characteristics of C. barometz under different temperature conditions were analyzed based on the experimental results. The results indicated that following exposure to 5 ℃ and 15 ℃, the photosynthetic capacity of C. barometz leaves significantly decreased, whereas the activities of superoxide dismutase (SOD) and peroxidase (POD) markedly increased. In contrast, no significant differences were observed in the levels of free proline (Pro) and soluble sugars. After 15 days of treatment at 5 ℃, the malondialdehyde (MDA) content in the leaves of C. barometz significantly increased. Proper low-temperature treatment significantly enhanced the accumulation of total flavonoids in the leaves of C. barometz. On the 10th day of treatment at 5 ℃and 15 ℃, the total flavonoid content reached 688.78% and 511.01% of that in the 25 ℃ treatment group, respectively, representing the highest levels observed. This study demonstrated that low-temperature stress exerts differential effects on various physiological indicators in C. barometz. The activities of SOD and POD, and the total flavonoid content, can serve as key indicators for evaluating the cold tolerance of C. barometz seedlings. Temperatures of 15 ℃ and below can significantly reduce the photosynthetic capacity of C. barometz, leading to abiotic stress and a marked increase in the total flavonoid content in its leaves. This result could provide an important reference for optimizing temperature control conditions in the artificial cultivation of. C. barometz.

Considering the deficiencies such as low substrate utilization rate, prone to lose typical flavor, and weak taste in liquid fermentation process of pineapple vinegar, the paper intended to explore the effects of different carbon sources (sucrose, inulin) and nitrogen sources (chromium-rich yeast, soybean protein) on the physicochemical indexes (total acid, reducing sugar, total polyphenols and total acid), antioxidant activity (DPPH free radical and ABTS⁺ clearance rate) and volatile components in the fermentation process of pineapple vinegar, which was aimed to improve substrate utilization and vinegar quality. The results showed that not only different carbon sources and but also nitrogen sources could significantly increase the acid production of acetic acid bacteria, and the abilities of nitrogen sources to promote the utilization of reducing sugar and acid production of acetic acid bacteria were better than that of carbon sources. The nitrogen source had higher effects on the contents of total polyphenols, total flavonoids and the ability of scavenging DPPH and ABTS free radicals than carbon source. Besides, a total of 37 volatile components were detected in pineapple vinegar under four treatments, mainly included esters, alcohols, acids, phenols, ketones and so on. The total concentration of volatile components of pineapple vinegar in nitrogen source treatments was higher than that in carbon source treatments. The concentrations of esters and acids were the highest with value of 3712.37 μg/L and 972.97 μg/L, and were 6.39 times and 8.76 times of those in the sucrose treatment, respectively. Compared with sucrose treatment, the total concentration of volatile components in other treatments increased by 3.78-5.19 times. There were two key volatile compounds in the sucrose treatment (ethyl decanoate and phenylethanol), ethyl caproate, isoamyl acetate, ethyl decanoate and phenyl ethyl) were key volatile compounds in the inulin treatment, and five key volatile compounds in the nitrogen source group were isoamyl acetate, ethyl caproate, ethyl decanoate, linalool and phenylethanol. Appropriate addition of organic nitrogen source could promote acetic acid fermentation process, maximize the fermentation potential of acetobacter, enhance antioxidant activity of pineapple vinegar, to improve the content of total phenol and total flavone, and pineapple vinegar flavor.

It was aimed to investigate the characteristics of variations in color and sugar components within sweet potato tuberous root under diverse storage temperatures and to offer references for the formulation of storage and quality control measures for sweet potato tuberous root. The sweet potato tuberous root of Pushu 32 was respectively stored in environments of 25 ℃ (normal temperature control), 14 ℃ (low-temperature treatment), and –4 ℃ (near -freezing temperature treatment). The color of the tuberous root was measured using a colorimeter, and the contents of total soluble sugar, sucrose, fructose, glucose, and starch within the tuberous root were determined. Meanwhile, the activity of amylase, neutral invertase, and acid invertase involved in sugar metabolism of the tuberous root was measured, and the correlation analysis was conducted on color and sugar contents. During the storage period (0-60 days), the L^* value of the tuberous root at 25 ℃ control and 14 ℃ did not exhibit significant changes compared with the initial sampling point (0 days), while the L^* value of the tuberous root at –4 ℃ was consistently significantly lower than that of the initial sampling point. The a^* and b^* values of the tuberous root at the three temperatures fluctuated with the prolongation of the storage time. Under the 14 ℃, the content of soluble sugar in the tuberous root gradually increased with the extension of the storage time, and the sucrose content of the tuberous root under the 14 ℃ was always higher than that of the 25℃control and –4 ℃ treatment during the same period. The starch content of the tuberous root at the three temperatures significantly decreased with the prolongation of the storage time. In the early stage of storage (0-20 days), the activity of amylase, neutral invertase, and acid invertase within the sweet potato tuberous root at –4℃ was higher than those at 25 ℃ and 14 ℃. The correlation analysis indicated that the starch c ontent of the tuberous root was extremely significantly negatively correlated with neutral invertase and acid invertase; the L^* value, b^* value, and H° value of the tuberous root were extremely significantly positively correlated with sucrose, which could be utilized as indicators for evaluating the sucrose content in the tuberous root. Thus, among the three storage temperatures, 14 ℃ induced the best saccharification effect on sweet potato tuberous root, effectively facilitating the accumulation of soluble sugar substances within the tuberous root, and could be regarded as a more suitable storage temperature for this variety; –4 ℃exerted a considerable influence on the color change of sweet potato tuberous root. The color change during the storage process of the tuberous root was closely related to sugar metabolism, and invertase might be the key enzyme regulating the metabolism of soluble sugar during the storage process of this variety. The research findings would offer a reference for enhancing the quality characteristics and optimizing the processing techniques of sweet potato processed products.

In order to investigate the biocontrol ability and mechanism of Burkholderia GXMZU-5 with quorum quenching activity, the biocontrol effect was verified through experiments on bacterial soft rot of banana fruits and potted seedlings (Dickeya zeae GR-1), and the biocontrol mechanism was verified by measuring the content of biofilm, the ability to remove extracellular polysaccharides, the ability to inhibit the metabolic activity of biofilm, and PCR amplification of QQ enzyme homologous genes. The results showed that GXMZU-5 could effectively degrade acylhomoserine lactone (AHLs) signal molecules and had AHLs quenching ability. In the biocontrol experiment on banana fruits, the surface of the mixed bacteria experimental group was healthier than that of the control group, with no obvious black spots or soft rot signs. The cross-section and longitudinal section results of banana fruits showed that the lesion area of the treatment group was significantly reduced. In the potted plant control experiment, there were no obvious signs of rot at the injection site of the mixed bacteria group, and the natural plant height recovered by 56% compared with the pathogen group, indicating that GXMZU-5 had a significant inhibitory effect on the disease caused by Dickeya zeae GR-1. The results for exploring of the biocontrol mechanism showed that the total content of biofilm and the content of extracellular polysaccharides in the mixed bacteria system were lower than those of the two bacteria cultured separately. The MTT method for measuring biofilm metabolism indicated that GXMZU-5 could effectively reduce the biofilm metabolic activity of Dickeya zeae GR-1 and occupied a dominant position in the mixed bacteria system. The exploration of the biocontrol mechanism indicated that GXMZU-5 could reduce the biomass and vitality of Dickeya zeae GR-1 biofilm through quenching effect, thereby obtaining biocontrol ability. The amplification of QQ enzyme homologous genes showed that GXMZU-5 had the aiiA lactonase gene and could quench AHLs signal molecules. This study verified the biocontrol ability of GXMZU-5 and preliminarily explored its biocontrol mechanism, providing a certain reference basis for the use of quenching bacteria to control plant bacterial diseases.

Wilt caused by Fusarium oxysporum f. sp. Cubense is currently the most serious disease affecting the sustainable and healthy development of the global banana industry. To screen superior arbuscular mycorrhizal (AM) fungi that significantly promote the growth and disease resistance of banana tissue culture seedlings, this study compared the effects of five dominant AM fungi isolated from the main banana producing areas in Guangxi on the growth and Fusarium wilt of banana tissue culture seedlings under pot conditions. The results showed that the mycorrhizal infection rate of banana tissue culture seedlings inoculated with AM fungi ranged from 15.00% to 95.00%, they were as follows: BNMJ-1 (C. etunicatum) > BNTJ-6 (G. mosseae) > HTJ2-60 (C. lamellosum) > BDQJ-2 (G. fulvum) > GZXJ-10 (Paraglomus sp.). All the inoculation treatments significantly promoted the growth of banana tissue culture seedlings except for the GZXJ-10 treatment, and the results of membership function comprehensive analysis showed that the BNMJ-1 treatment had the most significant growth-promoting effect, which increased plant height, stem diameter, number of leaves, maximum root length and total biomass by 68.60%, 44.54%, 40.67%, 12.05% and 65.15%, respectively, compared with the control, followed by the BNTJ-6 treatment. BNMJ-1 treatment was the most effective in wilt control, followed by BNTJ-6 treatment, which decreased the disease index by 93.37% and 89.03% compared to the control and the preventive efficacy reached 93.64% and 88.85%. In summary, among the five AM fungi for testing, the strains with better disease-promoting resistance to banana seedlings grown in tissue culture were BNMJ-1 and BNTJ-6. Therefore, screening to obtain the advantageous AM fungal strains for banana tissue culture seedlings lays the foundation for the later development of banana mycorrhizal seedlings as well as special mycorrhizal fungal fungicides and fungal fertilizers.

Atg26 (or Ugt51) is a UDP-glucose: sterol glucosyltransferase, which regulates the biological process of sterol conversion to sterol glucoside (SG), participates in various cellular autophagy processes, and plays an important role in fungal growth, development and pathogenicity. In order to investigate the role of Atg26 in the growth, development and virulence of Peronophythora litchii, six Atg26 homologous proteins were identified through bioinformatics. The analysis of protein properties showed that the secondary structure of the protein was mainly random curling and had hydrophilic properties. The results of gene and protein structure analysis showed that except PlATG26a, the other ATG26 homologous genes of P. litchii had introns, which were mostly distributed at the end of the gene. All Atg26 homologous proteins contained the CAT catalytic domain, but did not have the PH (pleckstrin homology) and GRAM (glucosyltransferase, Rab-like GTPase activators, and myotubularins) domains that make up the PBD (phosphoinositide binding domain). Further phylogenetic and conserved motif analysis of Atg26 homologous proteins found that diversity existed among the Atg26 homologous proteins in P. litchii, but the CAT domain of Atg26 was conserved in different species. Protein interaction prediction and protein molecular docking analysis showed that the interacting proteins of PlAtg26 were mostly located in the cytoplasm or membrane, concentrated in the process of cell metabolism, and had catalytic activity, REDOX activity or binding ability, which also indicated that PlAtg26 may not require the binding ability of GRAM domain for localization. Quantitative real-time PCR (qRT-PCR) analysis showed that PlATG26b was up-regulated in zoospore stage and early infection, but had no significant difference in sporangium stage and late infection. This result also indicated that Atg26 played an important role in the asexual reproduction and infection of P. litchii. In conclusion, PlAtg26 and Atg26 homologues in fungi have significant structural differences and may show different biological functions from fungi.

Paurocephala sauteri Enderlein is an important pest of tropical and subtropical mulberry, which seriously threatens the diversified development of tropical sericulture industry. Fatty acyl-CoA reductase (FAR) exists in various organisms and participates in the biosynthesis of fatty acid derivatives, and then participates in many life activities such as wax synthesis, reproduction, sexual information recognition and communication. A total of 23 FAR genes were screened in this study. Protein analysis showed that most of them were alkaline proteins with hydrophilicity. Subcellular localization prediction found that 17 FAR proteins were located in the cytoplasm, one FAR proteinin the mitochondria, one FAR protein in the nucleus, and four FAR proteins in the plasma membrane, indicating that the main place for the PsmFAR gene to function was the cytoplasm. Combined with the function of other known insect FAR genes and the expression analysis of FAR genes in nymphs, female adults, male adults and different parts of P. sauteri, it was found that FAR genes could be involved in development, reproduction, wax synthesis, cuticle synthesis, pheromone synthesis and detoxification. In addition to seven genes only involved in wax synthesis, the remaining 16 genes may be involved in multiple biological functions, including 16 genes (69.56%) involved in reproduction, 16 genes (69.56%) involved in wax synthesis, 12 genes (52.17%) involved in cuticle synthesis, and nine genes (39.13%) involved in development. There were five genes (21.74%) related to detoxification and four genes (17.39%) related to pheromone synthesis. In this study, based on the transcriptome sequencing analysis, the identification, sequence composition and expression analysis of the FAR gene family were carried out to explore the function of the FAR gene in the life activities of the P. sauteri, and to provide a theoretical basis for its efficient prevention and control technology and the development and application of targeted insecticides. Further verification of subsequent functions would provide a basis for the development of precise prevention and control agents targeting the FAR gene.

Red fire ant, Solenopsis invicta, a serious invasive pest native to South America, has been widely distributed in China, posing significant threats to agriculture, natural ecosystems, and public health. Effective entry-exit quarantine measures are essential to prevent the invasion and spread of S. invicta, which requires rapid and accurate identification of the pest. Existing detection methods, including morphological identification, DNA barcoding, immunoassay, and loop-mediated isothermal amplification (LAMP) have limitations in simplicity, detection speed and sensitivity. Recombinase polymerase amplification (RPA) is an isothermal amplification technique characterized by its simplicity, high sensitivity, and efficient amplification. To enable rapid and accurate on-site detection of S. invicta, this study developed a visual detection method based on RPA technology. Mitochondrial genome sequences of S. invicta and closely related or morphologically similar species were analyzed using data from the NCBI database. The mitochondrial NADH₂ dehydrogenase gene was selected as the target for amplification, and specific RPA primers were designed. Experimental results confirmed that the primers demonstrated high specificity for S. invicta. Sensitivity testing using agarose gel electrophoresis revealed that the RPA reaction could detect as low as 1.0×10^-4 ng/μL, which is 10³ times more sensitive than conventional PCR. A visual detection method was further developed by incorporating nucleic acid dyes into the reaction, achieving a sensitivity of approximately 1.0×10^-1 ng/μL. Additionally, a rapid DNA extraction method was explored. This method involved grinding ant samples in sterile water followed by heating at 100 ℃ in a water bath for one minute, which successfully yielding crude DNA. The developed method enables gene amplification of S. invicta at 37 ℃, with detection results assessed via fluorescence reactions, completing the entire process within 30 minutes. This approach provides a convenient, rapid, accurate, and reliable technical method for detecting S. invicta, offering valuable technical support for its quarantine, prevention and control.

Pathogenic bacteria are the primary causative agents of economic losses in the aquaculture industry, and biological control is currently regarded as a promising strategy for prevention and management. Algae, as crucial components of marine ecosystems, host diverse and abundant microbial communities within their phycospheres. In order to explore the diversity and potential application value of algae-associated symbiotic or epiphytic actinomycetes resources in South China Sea, the isolation identification and antibacterial activity screening of symbiotic or epiphytic actinomycetes from Caulerpa sertularoides f. Longipes, collected from Lingshui, Hainan, were carried out. Actinomycetes were isolated through dilution coating method and identified according to the 16S rRNA gene sequences alignment and by phylogenetic tree construction. The results revealed that 20 strains were identified as Streptomyces, one as Nocardiopsis, and one as Microbacterium. The antibacterial activity of the fermented crude extracts of the obtained strains was evaluated against nine pathogenic bacteria, including Vibrio owensii using the filter paper method. Results showed that all strains exhibited inhibitory effects on at least one type of bacteria. High-performance liquid chromatography (HPLC) was employed to assess the chemical diversity of the crude extracts. Results showed that strain HZ057 had a higher abundance of secondary metabolites than other strains. To further investigate the salt stress tolerance of the strains, salt tolerance tests were conducted. The results showed that all the strains could grow well on 0%-4% NaCl, HZ054 and HZ057 could still grow at a salt concentration of 12%. The whole genome of HZ057 was sequenced and the functions of each gene cluster were predicted using antiSMASH. The analysis revealed that the genome contained 29 secondary metabolite genes clusters with diverse structural types, indicating that this strain is associated with a rich diversity of secondary metabolites. In this study, strains of Streptomyces, Nocardiopsis and Micrococcus were isolated firstly from the algae Caulerpa sertularoides f. Longipes in the South China Sea, indicating that the algae contained abundant actinomycete resources. Moreover, it was found that the identified strains exhibited significant antibacterial activity and the ability to produce a variety of secondary metabolites, suggesting the potentials for future research and applications.