Project description:Senescence is initiated immediately in harvested tea leaves, and leads to physiological and biochemical changes, and could affects the final tea products. In the present work, we investigated the relationship between hormones and critical components in harvested tea leaves before withering, changes in hormones including abscisic acid (ABA), salicylic acid (SA), jasmonic acid (JA), and critical components like catechins, theanine, and caffeine were analyzed. Significant changes in these substances were identified and ABA correlated with catechin in harvested tea leaves before withering. RNA-seq transcriptome analysis revealed dramatic differences between tea samples at 1 h and 2 h compared with those at 0 h. The patterns of these three critical components correlated with the expression profiles of differentially expressed genes (DEGs). Weighted correlation network analysis of co-expressed genes revealed that genes in the mediumpurple2 module correlated with ABA and catechins. The results of this study suggest that harvested tea leaves before withering undergo significant hormonal changes (ABA, JA, and SA) and ABA may participate in regulating catechin biosynthesis.
Project description:Cysteine S-nitrosylation is a reversible protein post-translational modification and critically regulates the activity, localization and stability of proteins. Tea (Camellia sinensis (L.)) is one of the most thoroughly studied evergreen crop due to its broad non-alcoholic beverage and huge economic impact in the world. However, to date, 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 multiple subcellular compartments, especially in the chloroplast and cytoplasm. The analysis of functional enrichment and PPI network revealed that the S-nitrosylated proteins were mainly involved in carbon metabolism, especially in Calvin cycle and TCA cycle. These results suggested that S-nitrosylated proteins in tea leaves might play critical regulatory roles in the carbon metabolism. Overall, this study not only globally analyzed the functional annotation of cysteine S-nitrosylation in tea leaves, but also preliminarily provided the valuable information for further investigating the functions of cysteine S-nitrosylation in tea plants.
Project description:Anthracnose disease is caused by Colletotrichum gloeosporioides, and is common in leaves of the tea plant Camellia sinensis. MicroRNAs (miRNAs) have been known as key modulators of gene expression in defense responses; however, the role of miRNAs in tea plant during defensive responses to C. gloeosporioides remains unexplored. Six miRNA sequencing data sets and two degradome data sets were generated from C. gloeosporioides-inoculated and control tea leaves. A total of 485 conserved and 761 novel miRNAs were identified. Of those, 239 known and 369 novel miRNAs exhibited significantly differential expression under C. gloeosporioides stress. 1134 and 596 mRNAs were identified as targets of 389 and 299 novel and conserved miRNAs by degradome analysis, respectively. The expression levels of twelve miRNAs and their targets were validated by quantitative real-time PCR. The predicted targets of five interesting miRNAs were further validated through 5'RLM-RACE. Furthermore, Gene Ontology and metabolism pathway analysis revealed that most of the target genes were involved in translation, carbohydrate metabolism and signal transduction pathways. This study enriches the resources of defense-responsive miRNAs and their targets in C. sinensis, and thus, provides novel insights into the miRNA-mediated regulatory mechanisms underlying immunity responses to biotic stress in tea plant.
Project description:In field conditions, tea plants are often exposed to drought stress, which has profound effects on the growth and development of tea plants. However, most studies on tea plants in response to drought stress focused on single gene or protein expression, and transcriptome or proteome profiles, the impact of drought stress on ubiquitination in proteins remains unearthed. We performed a global profile of ubiquitinated (Kub) proteins in tea leaves under drought stress. 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 were down-regulated compared with drought and control. Furthermore, we analyzed the Kub proteins related to ubiquitin-mediated proteolysis, catechins biosynthesis, and carbohydrate and amino acid metabolism in tea leaves under drought stress. The results indicated that many Kub proteins involved in ubiquitin-mediated proteolysis played important roles in protein degradation. Several Kub proteins related to catechins biosynthesis were positively correlated with each other because of their co-expression and co-localization. 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 under drought stress.
Project description:In this study, we performed deep sequencing and bioinformatics analyses of tea plant leaves to identify and characterize known and novel miRNAs. A total of 26,876,261 raw reads were produced from 2 libraries. We detected 422 known miRNAs belonging to 125 families, and 68 putative novel miRNAs.
Project description:The tea plant (Camellia sinensis (L.) O. Kuntze) is often commercially used as a source of non-alcoholic beverages and is an economically important woody crop (Chen et al., 2007). As living standards have improved, the requirement for high-quality life has increased in modern society. ‘Anji Baicha’ (alias ‘Baiye 1’ or ‘White Leaf 1’) is an excellent tea cultivar with albino phenotype and it is popular in producing high-quality green tea. The traits of ‘Anji Baicha’ are as follows. Young ‘Anji Baicha’ shoots are yellow-green when the early spring temperature is below 20°C. As the leaves fully expand, the leaves become white. The leaves gradually return to green when the environmental temperature increases (Cheng et al., 1999; Li et al., 2002, 2011). Previous reports have suggested a positive correlation between amino acid concentration and albinism as well as a negative correlation between tea polyphenols and albinism (Li et al., 1996; Du et al., 2006; Xiong et al., 2013). Therefore, the quality of ‘Anji Baicha’ is much higher when new shoots become albino due to their rich amino acid content and modest tea polyphenol content. Plants adjust their metabolism in response to environmental stimuli to eventually bring about changes in protein activities and levels, and this adaptive process includes posttranslational protein modifications (PTMs) (Prabakaran et al., 2012). PTMs have been reported to regulate various processes, including DNA interaction, protein-protein interactions, enzyme activation and protein stability. Among the hundreds of different PTMs, lysine acetylation is an abundant, reversible and highly regulated PTM (Zhang et al., 2009; Wu et al., 2011).