Abscisic acid (ABA) is an important phytohormone responsible for activating drought resistance, but the regulation mechanism of exogenous ABA on tea plants under drought stress was rarely reported. Here, we analyzed the effects of exogenous ABA on genes and metabolites of tea leaves under drought stress using transcriptomic and metabolomic analysis. The results showed that the exogenous ABA significantly induced the metabolic pathways of tea leaves under drought stress, including energy metabolism, amino acid metabolism, lipid metabolism and flavonoids biosynthesis. In which, the exogenous ABA could clearly affect the expression of genes involved in lipid metabolism and flavonoid biosynthesis. Meanwhile, it also increased the contents of flavone, anthocyanins, flavonol, isoflavone of tea leaves under drought stress, including, kaempferitrin, sakuranetin, kaempferol, and decreased the contents of glycerophospholipids, glycerolipids and fatty acids of tea leaves under drought stress. The results suggested that the exogenous ABA could alleviate the damages of tea leaves under drought stress through inducing the expression of the genes and altering the contents of metabolites in response to drought stress. This study will be helpful to understand the mechanism of resilience to abiotic stress in tea plant and provide novel insights into enhancing drought tolerance in the future.

Background: Different mulches have variable effects on soil physicochemical characteristics, bacterial and fungal communities and ecosystem functions. However, the information about soil microbial diversity, community structure and ecosystem function in tea plantation under different mulching patterns was limited. In this study, we investigated bacterial and fungal communities of tea plantation soils under polyethylene film and peanut hull mulching using high-throughput 16S rRNA and ITS rDNA gene Illumina sequencing. Results: The results showed that the dominant bacterial phyla were Proteobacteria, Actinobacteria, Acidobacteria and Chloroflexi, and the dominant fungal phyla were Ascomycota, Mortierellomycota and Basidiomycota in all samples, but different mulching patterns affected the distribution of microbial communities. At the phylum level, the relative abundance of Nitrospirae in peanut hull mulching soils (3.24%) was significantly higher than that in polyethylene film mulching soils (1.21%) in bacterial communities, and the relative abundances of Mortierellomycota and Basidiomycota in peanut hull mulching soils (33.72, 21.93%) was significantly higher than that in polyethylene film mulching soils (14.88, 6.53%) in fungal communities. Peanut hull mulching increased the diversity of fungal communities in 0-20 cm soils and the diversity of bacterial communities in 20-40 cm soils. At the microbial functional level, there was an enrichment of bacterial functional features, including amino acid transport and metabolism and energy production and conversion, and there was an enrichment of fungal functional features, including undefined saprotrophs, plant pathogens and soils aprotrophs. Conclusions: Unique distributions of bacterial and fungal communities were observed in soils under organic mulching. Thus, we believe that the organic mulching has a positive regulatory effect on the soil bacterial and fungal communities and ecosystem functions, and so, is more suitable for tea plantation.

Background: Fulvic acid (FA) is a kind of plant growth regulator, which can promote plant growth, play an important role in fighting against drought, improve plant stress resistance, increase production and improve quality. However, the function of FA in tea plants during drought stress remain largely unknown. Results: Here, we examined the effects of 0.1 g/L FA on genes and metabolites in tea plants at different periods of drought stress using transcriptomics and metabolomics profiles. Totally, 30,702 genes and 892 metabolites were identified. Compared with controlled groups, 604 and 3331 differentially expressed metabolite genes (DEGs) were found in FA-treated tea plants at 4 days and 8 days under drought stress, respectively; 54 and 125 differentially expressed metabolites (DEMs) were also found at two time points, respectively. Bioinformatics analysis showed that DEGs and DEMs participated in diverse biological processes such as ascorbate metabolism (GME, AO, ALDH and Lascorbate), glutathione metabolism (GST, G6PDH, glutathione reduced form and CYS-GYL), and flavonoids biosynthesis (C4H, CHS, F3'5'H, F3H, kaempferol, quercetin and myricetin). Moreover, the results of co-expression analysis showed that the interactions of identified DEGs and DEMs diversely involved in ascorbate metabolism, glutathione metabolism, and flavonoids biosynthesis, indicating that FA may be involved in the regulation of these processes during drought stress. Conclusion: The results indicated that FA enhanced the drought tolerance of tea plants by (i) enhancement of the ascorbate metabolism, (ii) improvement of the glutathione metabolism, as well as (iii) promotion of the flavonoids biosynthesis that significantly improved the antioxidant defense of tea plants during drought stress. This study not only confirmed the main strategies of FA to protect tea plants from drought stress, but also deepened the understanding of the complex molecular mechanism of FA to deal with tea plants to better avoid drought damage.

Drought and heat stresses can influence the expressions of genes, and thereby affect the growth and development of plants. Alternative splicing (AS) of genes plays crucial roles through increasing transcriptome diversity in plant stress responses. Tea plants, widely cultivated in the tropics and subtropics, are often simultaneously exposed to drought and heat stresses. In the present study, we performed a global transcriptome of tea leaves treated with drought, heat or their combination. In total, 19,019, 20,025 and 20,253 genes underwent AS in response to drought (DT), heat (HT) and their combined stress (HD), respectively, of which 12,178, 11,912 and 14,413 genes differentially spliced in response to DT, HT and HD, respectively. Also, 2,447 specific differentially spliced genes (DSGs) were found only in response to HD. All DSGs accounted for  48% of the annotated genes in tea tree genome. Comparison of DSGs and differentially expressive genes (DEGs) showed that the proportions of HT and HD-induced DSGs were 13.4% and 9.2%, while the proportion of DT increased to 28.1%. Moreover, the DEG-DSG overlapped genes tended to be enriched in a wide large of pathways in response to DT. The results indicated that the AS of genes in tea leaves was extensively triggered by drought, heat and their combined stresses. In addition, the AS enhanced the transcriptome adaption in response to drought and heat stresses, and the AS also provoked specific molecular functions in response to drought and heat synergy stress. The study might have practical significance for molecular genetic breeding of tea plants with stress resistance.

Drought stress often affects the expression of genes and proteins in tea plants. However, the global profiling of ubiquitinated (Kub) proteins in tea plants remains unearthed. Here, we performed the ubiquitome in tea leaves under drought stress using antibody-based affinity enrichment coupled with LC-MS/MS analysis. In total, 1,409 lysine Kub sites in 781 proteins were identified, of which 14 sites in 12 proteins were up-regulated and 123 sites in 91 proteins down-regulated under drought stress. The identified Kub proteins were mainly located in the cytosol (31%), chloroplast (27%) and nuclear (19%). Moreover, 5 conserved motifs in EKub, EXXXKub, KubD, KubE and KubA were extracted. Several Kub sites in ubiquitin-mediated proteolysis-related proteins, including RGLG2, UBC36, UEV1D, RPN10 and PSMC2, might affect protein degradation and DNA repair. Plenty of Kub proteins related to catechins biosynthesis, including PAL, CHS, CHI and F3H, were positively correlated with each other due to their co-expression and co-localization. Furthermore, some Kub proteins involved in carbohydrate and amino acid metabolism, including FBPase, FBA and GAD1, might promote sucrose, fructose and GABA accumulation in tea leaves under drought stress. Our study preliminarily revealed the global profiling of Kub proteins in metabolic pathways and provided an important resource for further study on the functions of Kub proteins in tea plants.

Abstract. The effects of hydrogen sulfide (H 2 S) on cancer are controversial. Our group previously demonstrated that exogenous H 2 S promotes the development of cancer via amplifying the activation of the nuclear factor-κB signaling pathway in hepatocellular carcinoma (HCC) cells

Background: This research aims to study the efficacy of an integrated approach to prevent and treat the recurrence of intrauterine adhesions (IUA) after hysteroscopic adhesiolysis.Methods: A total of 96 patients diagnosed with moderate-to-severe intrauterine adhesions (IUA) in Nantong Maternal and Child Health Hospital from January 2016 to December 2019 were included in this parallel, randomized and single-center trial. Moderate (48 cases) and severe (48 cases) patients were randomly divided into three groups by a computer random generator: Group A (IUD, n=16), Group B, (Foley1w+IUD, n=16) and Group C (Foley1m+IUD, n=16). All patients received sequential treatment of estrogen and progesterone on the day of operation. Follow-up was performed at 1 and 3 months after treatment of uterine cavity, endometrial thickness, menstruation and pregnancy. Surgeons who performed the second-look and third-look hysteroscopy and postsurgical assessors were blinded to the randomization.Results: In total, 96 patients (48 cases in each degree) were included in the final analysis, with 16 cases in each group. No cases were lost to follow up. The primary outcome measure was AFS score, which was significantly lower in Group C than that of women in group A and Group B at 1 month (P<0.05). Similar results were observed at 3-month follow up. In patients with moderate adhesions, the pregnancy rate in Group C (Foley1m+IUD) was higher than that in Group A and Group B (P<0.05). However, in patients with severe adhesions, there was no significant difference in the pregnancy rate among the three groups (P>0.05).There was no statistical significance in infection indicators among the three groups of moderate and severe patients (P>0.05). Postoperative complications such as uterine perforation, severe bleeding, water poisoning and intrauterine infection were not observed. Conclusions:The effect of a Foley intrauterine balloon combined with IUD in preventing re-adhesion was better than that of an IUD alone. For patients with moderate adhesion, the prolongation of placement time could prevent intrauterine re-adhesion and significantly improve the pregnancy rate with strong safety.However, for patients with severe adhesions, the prolongation of intrauterine Foley balloon placement did not better prevent intrauterine re-adhesions, improve menstruation, or improve pregnancy rates.

Cysteine S-nitrosylation is a reversible protein post-translational modification and critically regulates the activity, localization and stability of proteins. Tea (Camellia sinensis (L.) O. Kuntze) is one of the most thoroughly studied evergreen crop due to its broad non-alcoholic beverage and huge economic impact in the world. However, little is known about the S-nitrosylome in this plant. Here, we performed a global analysis of cysteine S-nitrosylation in tea leaves. In total, 228 cysteine S-nitrosylation sites were identified in 191 proteins, representing the first extensive data on the S-nitrosylome in tea plants. These S-nitrosylated proteins were located in various subcellular compartments, especially in the chloroplast and cytoplasm. Furthermore, the analysis of functional enrichment and PPI network revealed that the S-nitrosylated proteins were mainly involved in multiple metabolic pathways, including glycolysis, pyruvate metabolism, Calvin cycle and TCA cycle. Overall, this study not only systematically identified the proteins of S-nitrosylation in cysteines of tea leaves, but also laid the solid foundation for further verifying the roles of S-nitrosylation in cysteines of tea plants.