Sucrose phosphate synthase (SPS) plays a crucial role in the sucrose synthesis process, and investigating the biological functions of the SPS family in durian (Durio zibethinus Murr.) can contribute to enhancing fruit quality. In the durian genome, 10 SPS members were identified and designated as DzSPS1 to DzSPS10. The results indicated that the average hydrophobicity coefficient was less than 0, with isoelectric points ranging from 5.70 to 6.68, suggesting that they are hydrophilic acidic proteins. Subcellular localization predictions primarily placed them on the cell membrane and nucleus. Analysis of conserved motifs within the gene family revealed variations in the number and distribution of motifs among durian SPS members, although all contained motif 3, indicating that motif 3 is a significant conserved domain within the durian SPS gene family. Gene structure analysis showed that durian SPS genes were structurally similar, containing 8 to 15 exons and 7 to 13 introns. Phylogenetic tree analysis demonstrated that durian SPS genes could be divided into two subfamilies, with subfamily Ⅱ comprising nine members and subfamily Ⅰ containing one member. Compared to SPS genes in horticultural fruit trees such as cacao and citrus, durian SPS genes exhibited closer phylogenetic relationships with Arabidopsis and rice SPS genes. Seven members of the durian SPS family shared high spatial structural similarity, with secondary structures predominantly consisting of α-helices and random coils. Cis-acting element analysis suggested that durian SPS genes may be readily induced by response elements related to light, low temperature, drought, and gibberellin. This study detected that the primary soluble sugars in durian fruit are sucrose, fructose, and glucose, with sucrose content significantly higher than that of fructose and glucose, and notable differences observed among different varieties. Fluorescence quantitative analysis revealed significant variations in SPS expression levels among different durian varieties, with the expression patterns of DzSPS3 and DzSPS7 correlating with changes in total sugar content between varieties, suggesting that DzSPS3 and DzSPS7 may be key members involved in sugar accumulation. By analyzing the structure and physicochemical properties of durian SPS genes and exploring the SPS accumulation characteristics in different varieties, this study would provide a reference for further investigation into the biological functions of the SPS family in durian.

In order to explore the characteristics and molecular regulation mechanism of high temperature albinism of tea variety Yaoqiu (YQ) and its molecular regulation mechanism, the effects of low temperature albinism on the shoot with one bud and two leaves of tea variety YQ in spring (YQC), summer (YQX), autumn albinism (YQQ) and autumn green (YQQL), and Baiye No. 1 (BY1H) in spring albinism (BY1HC), their biochemical components, and transcriptome sequencing were carried out on the new shoots in summer (BY1HX) and autumn (BY1HQ). The results of biochemical analysis showed that the total free amino acid content and tea polyphenols content of YQQ albino fresh leaves were lower than those of YQC green fresh leaves, and the difference of total free amino acid content was significant; while the total free amino acid content of BY1HC albino fresh leaves was significantly higher than that of BY1HQ green fresh leaves, and the tea polyphenols content was significantly lower than that of BY1HQ green fresh leaves. Cluster analysis revealed that the gene expression profiles of YQQ albino fresh leaves formed a distinct cluster. The comparison between YQQ and BY1HQ exhibited the highest number of differentially expressed genes. The new shoot leaves of YQ showed an albino phenotype induced by high-temperature stress in late summer and early autumn. This stress affected the structure of microtubules, cells, and subcellular components, leading to a reduction in the contents of amino acids and polyphenols. The three functional categories exhibiting the most significant gene enrichment were microtubule binding, movement of cellular or subcellular components, and non-membrane-bound organelles. Similarly, the top three pathways with the highest significance in gene enrichment were the flavonoid biosynthesis pathway, the starch and sucrose metabolism pathway, and the amino sugar and nucleotide sugar metabolism pathway. Through gene co-expression network analysis, modules exhibiting high expression levels were identified. Subsequently, the ten genes demonstrating the highest total connectivity (K value) were selected for further analysis and annotation. Notably, the functions of genes TGY042732 and the novel gene designated as novel.276 could not be predicted. These findings would provide a theoretical foundation for understanding the phenomenon of albinism in tea resources under conditions of elevated temperature.

The diversity of orchid labellum, a specialized petal, has great ornamental and biological value, but the formation mechanism has not been solved so far. APETALA3-3 (AP3-3) is a floral organ identity gene, which is related to the formation of orchid labellum, but there is no report on how it regulating the formation mechanism of orchid labellum diversity. In this project, wild type and DoAP3-3 overexpressing floral organs of Dendrobium officinale were used as the research objects to explore the formation mechanism from the perspective of transcription factor DoAP3-3 regulating downstream target genes through DAP-seq and RNA-seq joint analysis. The results showed that a total of 7 key candidate target genes, MADS6, NAC029, NAC054, WOX3, AS2, ERECTA, AG were identified, which may regulate floral organ development and floral morphogenesis development under the action of DoAP3-3 by specific regulation or interaction with other genes. The interaction between transcription factor DoAP3-3 and MADS6 was verified by yeast one-hybrid experiment, which further affecting floral morphogenesis development. This study would lay a foundation for preliminary analysis of the regulatory mechanism between DoAP3-3 and its target genes, and exploring the formation mechanism of highly specialized and diversified flower morphology in Orchidaceae.

Genetic engineering technology serves as an effective method to shorten crop breeding cycles, specifically cultivate new crop varieties, and identify plant gene functions. Induced promoters are important tools in genetic engineering research, among which thermally inducible promoters being extensively utilized in plant molecular biology owing to the simple vector structure, convenient induction, and low cost. At present, the development of genetic engineering technology in rubber trees lags behind. Functional studies of target genes typically use constitutive promoters, which limits the progress of related work. In this study, rubber tree calli were treated by heat. Through transcriptome sequencing analysis, identified eight genes that were non-expressed or minimally expressed, but exhibited high level expression after heat induction in calli. After heat induced expression changes and specificity evaluation, two candidate genes HbHSP17.6C and HbHSP17.6B that specifically respond to heat treatment were identified. Further through nested PCR, we cloned the 1962 nt sequence upstream of the start codon of the heat shock protein gene HbHSP17.6C. Confirm that it is composed of a core transcription region and multiple cis acting elements, and is named pHbHSP17.6C. It is inferred that this promoter could be used for gene function research in rubber trees and other closely related plants, which is expected to provide new tool options for related research.

Hyphal polarized growth in filamentous fungi requires tip-directed secretion of growth-related substances, and previous studies have shown that exocyst complex plays an important role in the processes of fungal secretion and polar growth. However, there are few researches on the hyphal polarized growth and pathogenic mechanism of obligate biotrophic fungi at present. Rubber tree (Hevea brasiliensis) is the most important source of natural rubber. Powdery mildew is one of the most serious diseases of H. brasiliensis, and its pathogen Erysiphe quercicola belongs to obligate parasitic fungi. In this study, EqExo70, a subunit of the exocyst complex, was identified in E. quercicola. The GFP labeled EqExo70 was expressed in the E. quercicola by electrotransformation method, and it was found that the protein showed fluorescence aggregation at the hyphal tip, suggesting that EqExo70 may be related to hyphal polarized growth. In addition, we silenced the EqExo70 by electroporating the reverse complementary sequence of EqExo70 into the E. quercicola, it was found that the pathogenic ability of E. quercicola decreased and the growth of hypha slowed down, suggesting that EqExo70 affects the pathogenicity of E. quercicola. The level of callose deposition and reactive oxygen species burst in H. brasiliensis significantly increased upon infection with the EqExo70-silenced strain, indicating that EqExo70 contributes to suppressing host immune response. The results indicated that EqExo70 is a key factor affecting pathogenicity of E. quercicola, and may be involved in the interaction with H. brasiliensis, as well as the hyphal polarized growth.

Natural rubber (NR) is an important industrial material and strategic resource. Its composition, structure, and properties are influenced by factors such as the rubber tree cultivar and processing methods, leading to significant variations in quality stability. By studying the changes in particle size and molecular weight of natural rubber prepared through different centrifugation cycles, this research explored the effects on rubber composition and performance, which is crucial for obtaining high-quality rubber. In this study, two rubber cultivars, Reyan 73397 and PR107, were selected to investigate the impact of different centrifugation cycles on the particle size of latex, molecular weight, physicochemical properties of raw rubber, and vulcanized rubber properties. After centrifugation, the particle size of the latex from both cultivars increased with the number of centrifugation cycles, and the particle size distribution became more concentrated, with Reyan 73397 having a larger particle size than PR107. The molecular weight decreased, and the molecular weight distribution narrowed as the centrifugation cycles increased. With more centrifugation cycles, the ash content, gel content, nitrogen content, and Mooney viscosity of both cultivars decreased, the vulcanization time extended, but the resistance to storage hardening increased. However, the tensile strength and tear strength were reduced. The aging resistance of the vulcanized rubber from both cultivars decreased with the increase of centrifugation cycles. Furthermore, centrifugal treatment increased the glass transition temperature (T_g) of the rubber, enhanced its resistance to wet sliding, and increased the rolling resistance and heat build-up of the rubber.

Tea plants (Camellia sinensis) is an essential economic crop in China with significant genetic diversity. Polyploidization, a key driver in species evolution, plays a crucial role in enhancing the economic traits of tea plants, providing new avenues for breeding improved varieties. This study aims to explore the ploidy differences between diploid and triploid tea plants by investigating the morphological, physiological, biochemical and metabolic traits. Utilizing flow cytometry, we identified the chromosome ploidy of 165 tea germplasm resources and discovered 11 new triploid tea plant varieties. The 11 triploid varieties, along with 12 diploid varieties, underwent a comparative study focusing on bud, leaf and anatomical characteristics. The results revealed significant differences between diploid and triploid tea plants in several traits, including phenological period, bud weight, leaf area, stomatal size and stomatal density. Triploid tea plants generally exhibited later budding, significantly higher bud weight, larger leaf areas, and larger stomatal dimensions, but lower stomatal density compared to diploid varieties. As the buds and leaves are vital for tea quality, the morphological and physiological differences can influence tea production and its overall quality. Furthermore, metabolomic analysis using UPLC-MS/MS technology was conducted on the triploid variety Xilianno. 1 and its maternal diploid Fuding Dabai (CK). A total of 1203 differential metabolites were detected, with 170 showing significant variation, of which 81 were upregulated and 89 were down regulated. The most abundant metabolites were flavonoids, followed by amino acids and their derivatives. The triploid variety displayed enhanced levels of metabolites associated with improved antioxidant activity and other health-related properties. The study would provide novel insights into the morphological, physiological and metabolic differences between diploid and triploid tea plants, offering valuable references for genetic assessment and breeding strategies. The findings also emphasize the significance of polyploidy in improving tea plant resilience, yield and quality, which is critical for the sustainable development of the tea industry.

Rubber tree latex metabolic processes are regulated by a variety of mechanisms, among which ubiquitination modification is the most significant. The phloem protein PP2 belongs to the F-box protein family and is specifically highly expressed in latex, which may be involved in the regulation of latex regeneration. In this study, bioinformatics and expression pattern analysis were conducted on 17 F-box members of the HbPP2 gene identified in the genome of Hevea brasiliensis. The results revealed that the majority of proteins encoded by the rubber tree PP2 genes were unstable hydrophilic proteins with molecular weights ranging from 9.402 to 61.206 kDa. Phylogenetic analysis showed that the 17 HbPP2 genes in the H. brasiliensis could be divided into three subgroups (Subgroup Ⅰ, Subgroup Ⅱ, Subgroup Ⅲ), in which HbPP2 members were completely absent in subgroup I. Analysis of cis-acting elements revealed that the rubber tree PP2 gene family contained diverse functional elements involved in growth and development regulation, hormone response, and light response. Subcellular localization analysis indicated that PP2 proteins were primarily localized in chloroplasts or cytoplasm. Tissue expression analysis showed that, except for some members with tissue-specific expression, most members of the rubber tree HbPP2 family were expressed in various tissues. In latex, the expression levels of six genes, HbPP2-B1, HbPP2-B1.1, HbPP2-B10.1, HbPP2-A13.2, HbPP2-B13 and HbPP2-A15.1, were relatively high, but tapping treatment significantly upregulated the expression of HbPP2-A13.2 and HbPP2-B13. This study would provide preliminary insights into the physicochemical and expression characteristics of the HbPP2 family members in the H. brasiliensis, laying a foundation for further research on the functions of this genes family in rubber trees latex synthesis and metabolism.

Mango (Mangifera indica L.), as a typical climacteric fruit, undergoes ripening and senescence processes closely related to ethylene. Ethylene-responsive factors (ERF) play crucial roles in plant growth, fruit ripening and ethylene signaling transduction. Mango variety Guifei was used, MiERF20, 492 bp long and encoding 163 amino acids, was cloned and analyzed. Bioinformatics analysis revealed that MiERF20 was an unstable, hydrophilic protein without signal peptides or transmembrane regions, containing 25 phosphorylation sites and one AP2 conserved domain. The secondary structure was dominated by 40.49% irregular coils, 33.13% α-helices, 16.56% extensions and 9.82% β-rotations. Its secondary structure comprised irregular coils, α-helices, extended chains, and β-turns, consistent with AP2 domain features. MiERF20 showed 83.89% homology with ERF20 of Lacertidae pistachio. Subcellular localization indicated that MiERF20 was located in the nucleus and possessed transcriptional activation activity. Prokaryotic expression assays demonstrated that the protein could be inducibly expressed in a prokaryotic system. Real-time fluorescence quantification showed that MiERF20 was ethylene-inducible, suggesting its role in ethylene-regulated fruit ripening. This study would provide a foundation for further analysis of the functions and regulatory mechanisms of ERF transcription factors during postharvest fruit ripening.

Natural rubber in the storage, transport process of rubber molecular chain on the aldehyde group condensaion reaction, results in the plasticity initial value, mooney viscosity and other indicators gradually increased, plasticity retention rate gradually decreased, making it more difficult to increase the plasticizing and mixing processes of natural rubber, and reduces the oxygen aging resistance of the rubber. It is necessary to prepare natural rubber with constant viscosity to reduce the condensation of aldehyde groups in the molecular chain of natural rubber. Alkylhydrazine (OP) solution was used to soak natural rubber by microbial coagulation to analyse the effects of OP solution concentration and wet film soaking time on the physical and chemical indexes, vulcanization characteristics, physical and mechanical properties of natural rubber, plasticity initial value, plasticity retention rate and mooney viscosity hardening value of natural rubber during storage. The results showed that plasticity initial value and mooney viscosity of natural raw rubber increased first and then decreased with the increase of the concentration of OP solution, but the plasticity retention rate was opposite. During the accelerated storage process, the plasticity initial value and mooney viscosity of natural raw rubber soaked in different concentrations of OP solution increased, while its plasticity retention rate decreased. With the increase of OP solution concentration, the hardening value of plasticity initial value, plasticity retention rate and mooney viscosity gradually decreased. With the concentration of OP solution ≥0.5%, the hardening value of plasticity initial value and mooney viscosity were ≤5. The effect of wet film soaking time on the physical and chemical indexes of natural raw rubber and the hardening values of the plasticity initial value, plasticity retention rate and mooney viscosity was not obvious. Compared with the control sample P₀, the natural rubbers (P₇, P₈, and P₉) soaked in 0.5% concentration of OP solution had slightly higher torque difference values ΔM of their blends, the tensile strength and tear strength of vulcanized rubber increased by 4.5%–14.2% and 3.0%–8.5%, respectively. In addition, the soaking time of wet film had a significant effect on the torque difference ΔM of the rubber and the tensile strength and tear strength of the vulcanized rubber. OP solution had a good constant viscosity effect on natural rubber. 0.5% concentration of OP solution soaked natural rubber had excellent physical and mechanical properties, and the production process was simple, not causing the waste of constant viscosity agent and the pollution of the production workshop, surrounding environment, easy to large-scale promotion and application.