Mutation breeding is one of the most promising approaches for increasing genetic and phenotypic variability in a short period of time. In order to explore the feasibility of creating a mango mutant gene library through mutagenesis. The study used Keitt mango as test materials, irradiated branches with ⁶⁰Co-γ ray and soaked seeds in EMS solution to create a mutagenesis population, and analyzed the Genetic diversity by SC-SSR molecular markers. The results indicated that the seemi-lethal dose of ⁶⁰Co-γ ray radiation is 31.37 Gy, and the semi-lethal time of immersion in 0.2% EMS solution is 5.9 hours. The genetic diversity of 100 mutagenized materials and Keitt material was analyzed through 16 pairs of SC-SSR primers, and a total of 117 polymorphic sites were detected. The average values of sexual locus, primer percentage of polymorphism bands, polymorphism information content (PIC), number of observed alleles (N_a), number of effective alleles (N_e), Nei's gene diversity index (H) and Shannon's information index (I) were 93.18%, 0.610, 1.923,1.583,0.334 and 0.493, respectively. The genetic similarity coefficient among test materials ranged from 0.373 to 0.984, with an average of 0.779. The study indicated that mutagenesis significantly enhanced genetic diversity in mango, among which EMS mutagenesis seed variation was greater, and the results lay a solid theoretical foundation for mango mutation breeding.

The study was aimed to explore the molecular mechanism of detoxification of prochloraz by Lasiodiplodia theobromae from mango and to screen related functional genes. In this study, RNA-seq technology was used to analyze the transcriptome sequencing and functional annotation of prochloraz-treated and untreated strains of L. theobromae. Prochloraz had significant inhibitory activity against the sensitive strain with an EC₅₀ value of 0.12 mg/L. The EC₅₀ value of the two resistant strains was 7.67 and 32.67 times higher than that of the sensitive strain, respectively. GO functional enrichment and KEGG signaling pathway enrichment analyses were performed for differentially expressed genes (DEGs) between prochloraz-sensitive strains (DF04) and -resistant strains (HL02 and M108). Compared with the untreated (CK) with prochloraz, there were 5342, 1148, and 2568 DEGs in DF04, HL02, and M108, respectively, after 10 mg/L prochloraz treatment. Among them, a total of 566 DEGs were overlapped among the three strains. Compared with the sensitive strains, the resistant strains had 2078 and 3096 DEGs up-regulated and 1527 and 1793 down-regulated expression, respectively. GO enrichment showed that the highest number of genes were involved in cellular process and metabolic process between resistant and sensitive strains after prochloraz treatment, accounting for 18% and 16%, 17% and 15% in HL02 and M108, respectively. KEGG enrichment showed that DEGs were significantly enriched in metabolic pathways between resistant and sensitive strains after prochloraz treatment, with 64.98% and 63.39% in HL02 and M108, respectively. The analysis for DEGs related to detoxification metabolism identified 27, 17 and 59 cytochrome P450 (Cytochrome P450), glutathione transferase (GST) and ABC transporter protein (ABC transporter) genes, respectively. Eight genes were randomly screened for quantitative real-time PCR validation, and the results confirmed that the trends in the relative expression of these genes were consistent with the transcriptome data. Based on the significantly up-regulated expression of DEGS in the resistant strains, the final screening of 7 P450s genes, 8 GSTs genes and 11 ABC transporter protein genes may be related to the metabolic resistance mechanism of L. theobromae to prochloraz. The results would provide new insights into the mechanism of fungicide resistance and lay the foundation for in-depth analysis of the molecular mechanism of metabolic resistance to prochloraz.

The soil ecological restoration and land recycling of the closed tailings reservoir not only avoid the risk of random discharge, but also increase the land use area. Mulberry has strong root system, strong stress resistance, large biomass and wide application. It has great potential in the remediation and reuse of heavy metals in mines. In this study, the growth of one-year-old seedlings of three mulberry varieties (Y120, G12 and G62) after 60 days of planting in arsenic and nickel combined pollution soil in the mining area and the enrichment of arsenic and nickel in different parts were compared by the original soil pot method. At the same time, the difference of rhizosphere soil microorganisms was analyzed by metagenomics to preliminarily elucidate the adaptability of different mulberry varieties to arsenic and nickel combined pollution mine soil and its relationship with rhizosphere soil microbial diversity. The results showed that after 60 days of planting, the pollution index of nickel in the rhizosphere soil of the three varieties decreased from moderate to mild before planting, and the pollution index of arsenic in the rhizosphere soil of G62 decreased from severe pollution to moderate pollution. The shoot and root growth of the three mulberry varieties were inhibited, but the growth of G62 was better than that of Y120 and G12, and the growth of G12 was worse. The transport coefficient and enrichment coefficient of arsenic in the three mulberry varieties were less than that of nickel. The enrichment ability of arsenic was root>leaf>stem. The accumulation of arsenic in roots accounted for 47.33%-50.52% of the total plant, and the difference between varieties was not significant. However, the enrichment ability of nickel was different among different varieties. The accumulation of nickel in roots accounted for 25.67% (G12), 38.46% (G62) and 47.14% (Y120) of the total plant, and the difference between varieties was significant. The richness of Nocardioides, Thiomonas and Rhizobium in the rhizosphere soil of G62 with better growth was significantly higher than that of G12 and Y120, and the richness of Thiomonas sp. in G62 was the highest. Combined with the fact that the arsenic pollution index of G62 rhizosphere soil decreased more, these genera and species may be more involved in the barrier absorption or detoxification of arsenic in mulberry rhizosphere. The richness of Sphingopyxis sp. was the highest in G12, and the variety had the lowest arsenic and nickel transferred and enriched in the body, which may be related to its more participation in the detoxification of arsenic and nickel combined pollution in mulberry. The results of this study will lay a foundation for the screening of mulberry varieties resistant to compound heavy metals that are suitable for the growth of mining areas and the screening and utilization of strains that can promote the growth of mulberry in the soil of arsenic and nickel combined pollution mines.

The aim of the study was to explore the anti-inflammatory activity of Qi-Nan essential oil (QEO) based on component analysis combined with the cellular inflammation model. The volatile components of QEO were analyzed by GC-MS. The antioxidant activity of QEO was detected by the measurement of DPPH radical scavenging and total antioxidant capacity. Bioinformatics was used to predict the targets and signaling pathways of QEO related to inflammation. NO and ROS levels were detected by fluorescent probe method. ELISA was used to detect the levels of inflammatory factors TNF-α, IL-6 and IL-1β. Western blot was used to detect the expressions of P-P65, P65, IκB-α and P-IκB-α. The main components of Qinan essential oil were 2-phenethyl-4H-chromen-4-one (50.08%), (-)-caryophyllene oxide (8.45%), patchulane (6.46%), elemol (3.88%), 2-methyl-6-(2-propenyl)-phenol (2.78%). The DPPH radicals scavenging of QEO was 51.98% at a concentration of 1 mg/mL and the total antioxidant capacity increased with the increase of QEO in the concentration range of 1-10 mg/mL. There were 533 intersecting targets of QEO and inflammation, and KEGG enrichment analysis showed that the main signaling pathways involved were MAPK, NF-κB and PI3K-Akt pathways. QEO significantly reduced the production and expression levels of NO, ROS, TNF-α, IL-6 and IL-1β (P<0.001). Meanwhile, the results of western blot showed that QEO also inhibited the expression of P-P65 and P-IκB-α proteins (P<0.001). Therefore, QEO can achieve anti-inflammatory activity through reducing the production of ROS, thereby inhibiting the activation of NF-κB signaling pathway and further drastically decrease the release of pro-inflammatory cytokines. The results demonstrate that QEO has the potential to be developed as an inflammation inhibitor.

GRAS is a plant-specific transcription factor, which plays an important regulatory role in plant growth and development, and abiotic stress response. GRAS gene family has not been reported in Hevea brasiliensis. In this study, bioinformatics tools were used to analyze the physicochemical properties, phylogenetic relationships, gene structures, chromosome positions, and cis-acting elements of promoters of GRAS gene family members in H. brasiliensis. The expression patterns of HbGRAS were analyzed by transcriptome data and real-time quantitative PCR (qPCR). A total of 91 GRAS family members were identified from H. brasiliensis genome, named HbGRAS1–HbGRAS91, with molecular weights ranging from 14.07–89.46 kDa. The results of subcellular localization prediction showed that HbGRAS was mainly localized in the nucleus and chloroplast. Those proteins were divided into 14 subfamilies based on phylogenetic analysis. The gene structures and motif compositions within the same subfamily were relatively conserved. The 91 GRAS family members were distributed in 17 chromosomes and two scaffolds except for chromosome 11 in rubber tree. We found that 17 HbGRAS genes were involved in 10 tandem repeat events. Collinearity analysis revealed the segmental duplication regions containing 87 HbGRAS genes, suggested that gene fragment duplication may be the major driver of GRAS gene expansion in H. brasiliensis. Cis-acting element prediction showed that HbGRAS family contained multiple phytohormone and stress-responsive elements. The expression patterns of HbGRAS genes had tissue specificity and were associated with leaf development. The expressions of DELLA genes, a member of the GRAS subfamily, were related to the xylem development and were repressed by gibberellin (GA). Those results provide a reference for functional research on the GRAS genes in rubber trees.

Fruit abscission in off-season longan is very serious during fruit development in Hainan, China, and severely affectse the formation of production. However, the research on the regulation of longan fruit abscission mainly is focused on fruit thinning, and there are very few studies on fruit preservation. The mechanism of abscission is mainly focused on hydrolase genes and reactive oxygen species, there is no report of fruit respiration on carbohydrate metabolism affecting fruit abscission. Previous studies showed that the decrease in carbohydrate level in fruit was closely related to fruit abscission. In order to further understand the relationship of carbohydrate metabolism and abscission, fruit clusters of off-season Chuliang longan were detached from tree body, the peduncles were immediately inserted into pure water and defoliation treatmented after detachment, which caused starvation stress and induced fruit abscission. Therefore, detachment of the fruit clusters from the tree served as starvation stress treatment. Change in the fruit abscission rate in the starvation stressed fruit clusters, respiratory oxygen consumption rate and fruit removal force in the three developmental stages under detachment were examined, and the effects of different light intensity on fruit respiration in the three stages were analyzed. It was found that longan fruit at different developmental stages differed in sensitivity to starvation stress, which rapidly initiated the fruit abscission response in all the three stages, but there were large differences in speed of fruit shedding. Young fruits responded to starvation stress for two days later than those in the middle and the late fruit development stage would lead to more intense fruit abscission response in the middle and the late stages. Respiratory oxygen consumption rate was the lowest in the young fruit stage. With the increase of light intensity, the respiration of young fruits did not cause a decrease in oxygen, but rather a release of oxygen. The decrease in the fruit removal force was also slower than that in the middle and late stages of fruit development. Therefore, it is concluded that fruit respiration was closely related to fruit abscission under starvation stress. Stronger fruit respiration intensity would result in faster fruit abscission under starvation stress and faster fruit removal force decreases. Young green fruits may carry out photosynthesis, which partially compensates for the respiratory consumption of carbohydrates in fruit, resulting in slower fruit abscission under starvation treatment. In the longan young fruit stage, the main reasons of slow fruit abscission under starvation stress are low respiratory oxygen consumption rate and certain photosynthetic capacity. Therefore, it is conclude that the young longan fruit is a partially autotrophic organ.

Chelonus formosanus is an important parasitic natural enemy of Noctuidae pests in Lepidoptera. In order to clarify the effects of different treatment of antennae on the behavioral response of C. formosanus, and the number of sensilla in antennae, the effects of antennae-excision of C. formosanus on the search for the honey sources and hosts, the longevity of the male and female wasps, the parasitism rate of the female wasps and the hatching rate of the host offspring were investigated, and the number of antennae receptors in different treatments was compared by using the scanning electron microscopy (SEM). The search time for honey sources of both the male and female wasps was the fastest when 1/3 of the flagella was removed, (79.59±23.22)s for female wasps and (106.52±26.71)s for male wasps. The search time for hosts of the female wasps was the fastest in the control group (204.38±24.01)s. However, no host could be found by wasps in the treatment groups with all antennae and all flagellum excised. In addition, compared with the control groups, the longevity of male and female wasps, the parasitism rate of female wasp, and the hatching rate of offspring were not significantly different under the different proportions of antennae excision. The SEM results showed that there were significant differences in the sensilla trichodea, the sensilla placodea, the sensilla basiconica, and the sensilla squamiformia between the different excision treatments. The results indicate that higher proportion of antennae removed would lead to greater impact on the search for honey source and host, indicating antennal sensilla played an important role in the search, localization and parasitism behaviors of C. formosanus.

The present study assessed the control efficiency of a predator, Cryptolaemus montrouzieri (Mulsant), on four mealybugs damaging tropical crops, including Paracoccus marginatus (Williams & Granara de Willink), Planococcus minor (Maskell), Planococcus citri (Risso), and Dysmicoccus neobrevipes (Beardsley). The daily predation of the 1st-4th instar larvae and adult C. montrouzieri on the 1st-3rd instar nymphs and adults of the four mealybug species, was observed indoors. The adult and high-age larvae of C. montrouzieri exhibited a high predation rate on the early instar nymphs of the four mealybug species. Notably, the predation rates were significantly higher on P. minor and P. marginatus compared to P. citri and D. neobrevipes. The first instar nymphs of C. montrouzieri did not prey on the adult and third instar nymphs of the four mealybug species, while the second instar nymphs lacked the ability to prey on mealybug adults. The predation ability of C. montrouzieri was ranked as follows: adults>fourth instar larvae>third instar larvae>second instar larvae>first instar larvae. Correspondingly, for the same instar of the ladybird, the predation rate on mealybugs of different instars followed the order: first instar nymphs>second instar nymphs>third instar nymphs>adults. In conclusion, C. montrouzieri demonstrates strong control capabilities on the four mealybugs damaging tropical crops.

Drought, high salinity and low temperature severely damage plant cells, inhibit plant growth, and significantly reduce crop yields. Ethylene-responsive factors (ERFs) in the AP2/ERF superfamily play a key role in plant growth and development, and in stress responses. To investigate the role of MeERF127 in the response of cassava to abiotic stress, this study cloned the MeERF127 gene from cassava and conducted sequence alignment, subcellular localization, transcriptional activity analysis, and expression pattern analysis. A gene-edited vector for MeERF127 was constructed to obtain transgenic cassava, and the phenotype and physiological indicators after drought, salt and cold stress treatments were analyzed, along with the expression of stress-responsive genes. The results showed that the full-length CDS region of the MeERF127 gene was 711 bp, and the amino acid sequence contained YRG and RAYD elements at the N- and C-termini, respectively, with alanine and aspartic acid at positions 14 and 19, indicating that MeERF127 belonging to the ERF subfamily. MeERF127 was localized in the nucleus and had transcription factor activity. MeERF127 was most highly expressed in stems, with the lowest expression in callus tissues, and its expression peaks during the tuber formation stage (80 days after planting). Its expression level increased after drought and salt stress and slightly decreased after cold stress. A gene-edited vector was constructed, and Agrobacterium-mediated transformation of cassava callus tissues resulted in MeERF127 gene-edited lines with 22 and 3 base pair deletions, as confirmed by Hi-TOM high-throughput sequencing. After drought and salt stress treatments, the gene-edited cassava did not wilt, while the wild-type cassava showed significant wilting. The gene-edited cassava had significantly higher SOD and POD enzyme activities and Pro content, and significantly lower MDA content compared to the wild-type cassava. The leaf color of the gene-edited cassava was lighter, and the expression levels of stress-responsive genes SOD and WRKY31 were significantly higher in the gene-edited cassava than those in the wild-type. After cold stress, both gene-edited and wild-type cassava wilted, with no significant differences in SOD and POD enzyme activities, MDA content, leaf color and stress-responsive gene expression between the gene-edited and wild-type cassava. These results suggest that the gene-edited MeERF127 enhances the drought and salt tolerance of cassava but does not respond to cold stress, indicating that MeERF127 may regulate the SOD and WRKY31 genes to respond to drought and salt stress. The findings of this study would provide insights into the role of the MeERF127 gene in cassava's response to drought and salt stress.

The changing patterns of soil chemical properties, enzyme activity, and microbial diversity in rubber plantations intercropped with three potato varieties (Jianchuanhong or JCH, Zishu or ZS, Daniujiao or DJN) were studied in this study. The results showed that rubber plantation intercropped with potatoes could significantly increase the soil organic matter, total nitrogen, total phosphorus, total potassium, alkaline dissolved nitrogen, effective phosphorus, soil β-glucosidase, N-acetyl β-D-glucosidase, acid phosphatase and aryl sulfatase activities, compared with rubber monoculture. There were significant differences among different potato varieties, with nutrient contents ranked as JCH>ZS>DJN, and enzyme activity ranked as DJN>JCH>ZS. Potatoes intercropped significantly increased the richness and diversity indexes of soil microorgnisms, and no significant differences among potato varieties. However, there was significant difference in the influence of different potato varieties on the abundance of specific microorgnisms in soil. The overall trend was that the abundance of specific bacterial such as Chloroflexi, Desulfobacterota were significantly decreased; the abundance of specific fungal such as Mortierellomycota, Chytridiomycota, and Kickxellomycota were significant increased. LEfSE analyses revealed that some beneficial microorganisms involved in material cycle or antagonistic to plant pathogens were enriched in the intercroppedg soil. DJN, ZS and JCH enriched 16, 26 and 31 marker microorganisms, respectively. Redundancy and correlation analysis showed that soil nutrient and enzyme activity were significantly correlated with the abundance of specific bacteria and fungi in the soil of rubber plantation. The increase of soil nutrients and enzyme activity decreased the abundance of specific bacterial and significantly increased the abundance of specific fungi. In conclusion, potato intercropped significantly increased soil nutrients, enzyme activity and soil microbial community diversity, but decreased the abundance of specific bacteria and increased the abundance of specific fungi. There were significant differences in the effects of different potato varieties on soil nutrients and enzyme activity, which may be related to the enrichment of different beneficial microorganisms. This study would provide a new idea and data support for the intercropping in rubber plantation.