The timing of spring bud break is a key economic trait in tea (Camellia sinensis) production, as early-harvested tea leaves possess substantially higher commercial value. While CsDREB17 has been implicated in the regulation of bud break, the mechanisms underlying its transcriptional control remain largely unresolved. In this study, we identified CsWRKY21 as a upstream transcription factor of CsDREB17 and demonstrated that CsWRKY21 directly binds to the CsDREB17 promoter and activates its transcription, using yeast one-hybrid, electrophoretic mobility shift assays (EMSA), and dual-luciferase reporter assays. Furthermore, both exogenous abscisic acid (ABA) and low temperature were found to upregulate CsWRKY21 expression and enhance its promoter activity, as revealed by qRT-PCR and GUS histochemical staining, respectively. Functional studies in tea plants showed that silencing CsWRKY21 promoted bud break, whereas overexpression of CsWRKY21 in Arabidopsis delayed seed germination, inhibited growth, and increased sensitivity to ABA and cold stress. Collectively, our results reveal that the CsWRKY21-CsDREB17 module plays a crucial role in spring bud dormancy release, providing new insights into the molecular regulation of this important agronomic trait in tea plants.

Huangjincha black tea, a high-amino-acid specialty cultivar, is prized for its refreshing taste and distinctive floral aroma; yet, molecular mechanisms governing flavor formation during withering remain unclear. This study integrated sensory evaluation, metabolomics, transcriptomics, proteomics, and quality-related chemical analyses to systematically elucidate the dynamic shifts and biosynthetic mechanisms underlying flavor formation during withering. Sensory evaluation and quality-related chemical measurements showed that moderate withering reduced bitterness and astringency while enhancing sweetness, umami, and mellowness in the tea infusion. Metabolomic analysis revealed significant accumulation of free amino acids, amino acid derivatives, and phenolic acids, accompanied by decreases in catechins and flavonoids during withering. Integrated transcriptomic and proteomic analyses identify amino acid and secondary metabolism as dominant processes during withering. CsSHMT1, CsCAT1, and CsGABA-T3 were identified as hub genes regulating amino acid metabolism. Notably, the phenylpropanoid pathway was identified as a pivotal metabolic hub that mechanistically links amino acid metabolism with aroma formation, thereby promoting the biosynthesis of key aroma-related compounds, including ferulic acid, coniferyl-aldehyde, and methyleugenol. These findings elucidate the coordinated metabolic and regulatory networks shaping flavor formation during withering, thereby providing a mechanistic basis for the targeted regulation of flavor in high-amino-acid black tea processing.

The tea plant is an economically important perennial crop whose yield and quality are severely constrained by cold stress. With the increasing frequency of extreme weather events, elucidating the molecular basis of cold tolerance is therefore essential for safeguarding tea production and its associated economic value. Catechins contribute to cold tolerance in tea plants, but the underlying regulatory mechanisms remain poorly understood. Here, we integrated transcriptomic, metabolomic, and physiological approaches to identify the CsMYB44-CsICE1 module, which regulates cold-induced flavonoid and catechin biosynthesis to enhance cold tolerance. Weighted gene co-expression network analysis (WGCNA) revealed that CsICE1 was strongly positively correlated with catechin accumulation and cold tolerance, whereas CsMYB44 was negatively correlated with these traits. Overexpression of CsICE1 in Arabidopsis improved cold tolerance by elevating flavonoid levels and upregulating antioxidant and cold-responsive genes, including AtSOD, AtPOD, and AtCBF1. Conversely, overexpression or silencing CsICE1 in tea plants significantly affected cold sensitivity. Overexpression of CsMYB44 reduced cold tolerance in Arabidopsis, while its silencing enhanced tolerance in tea plants. Yeast one-hybrid, electrophoretic mobility shift, and dual-luciferase assays demonstrated that CsMYB44 directly binds to the promoters of CsICE1, CsCHS (chalcone synthase), CsFLS (flavonol synthase), and CsANR (anthocyanidin reductase) to repress their expression. In contrast, CsICE1 activates the transcription of CsCHS, CsFLS, and CsANR. RT-qPCR analysis further indicated that short-term cold stress suppresses CsMYB44 expression, thereby releasing CsICE1, which subsequently upregulates CsCHS, CsFLS, and CsANR, promoting flavonoid and catechin accumulation and ultimately mitigating cold-induced damage. Collectively, these findings uncover a novel cold-tolerance mechanism in tea plants.

Low-temperature (LT) stress severely constrains tea production, yet the molecular mechanisms underlying the integration of jasmonic acid (JA) signaling and antioxidant defense remain elusive. Here, we demonstrate that chilling rapidly activates JA biosynthesis (Allene oxide synthase, CsAOS) and upregulates the WRKY transcription factor CsWRKY42 in Camellia sinensis. Weighted gene co-expression network analysis (WGCNA) identified the AP2/ERF family gene CsDREB2B as a hub co-expressed with CsWRKY42 and CsAOS. Functional studies revealed that CsDREB2B overexpression enhanced chilling tolerance in Arabidopsis by elevating JA levels, antioxidant activity (SOD, POD, APX), and reducing oxidative damage, while silencing CsDREB2B in tea plants heightened sensitivity. Crucially, CsWRKY42 directly activates CsDREB2B and CsAOS transcription by binding to their promoters, as confirmed by yeast one-hybrid (Y1H), dual-luciferase, and electrophoretic mobility shift assays (EMSAs). Silencing CsWRKY42 suppressed JA accumulation, antioxidant defense, and CsDREB2B expression. Exogenous methyl jasmonate (MeJA) rescued chilling tolerance and upregulated CsDREB2B and CsWRKY42. We further identified a superior CsDREB2B allele (Chr7:221282042-GG) and developed a dCAPS marker for germplasm screening. Our work elucidates a novel CsWRKY42-CsDREB2B module that synchronizes JA biosynthesis and antioxidant pathways to confer chilling tolerance, providing both mechanistic insights and a molecular tool for breeding cold-resilient tea cultivars.

The enhanced sensory quality of early spring tea is empirically associated with pre-harvest cold exposure, yet the chemical and mechanistic basis for this enhancement requires further clarification. In this study, we investigated the metabolic changes in tea leaves under cold acclimation (4/0 °C) compared to mild cooling (15/11 °C) using metabolomics, HS-SPME/GC × GC-Q-TOF-MS, gas chromatography-olfactometry (GC-O), and transcriptomic analyses. Results indicated that cold acclimation induced the accumulation of key non-volatile tastants, notably soluble sugars and γ-aminobutyric acid (GABA), driven by the activation of starch hydrolysis and polyamine degradation pathways. This provides the material basis for the sweetness and umami attributes of the tea infusion. Concurrently, volatilomic and GC-O analyses confirmed a shift in the aroma profile. The odor activity values (OAVs) and perceived sensory intensities of specific floral and sweet compounds, including trans-β-ionone, linalool, and (Z)-jasmone, were increased. This aroma development was closely linked to the accumulation of lipid precursors, the activation of jasmonic acid (JA) biosynthesis, and the subsequent upregulation of terpene synthases. Transcriptomic analysis and subsequent molecular validation verified that these carbon, nitrogen, and lipid fluxes are coordinated by transcriptional modules (e.g., CsERF21-CsAMY2), alongside a feedback loop that fine-tunes the signaling response. These findings demonstrate that cold acclimation acts as a natural pre-conditioning step that reprograms the raw leaf matrix, optimizing the chemical precursors essential for tea flavor. Ultimately, these metabolic markers and gene modules offer valuable targets for breeding high-quality tea cultivars and optimizing pre-harvest agricultural practices.

Calcium-dependent protein kinases (CDPKs) are important Ca2+ sensors that play crucial roles in plant responses to environmental stresses. However, the functions of CDPK genes in the tea plant (Camellia sinensis), especially in disease resistance, remain poorly understood. In this study, 32 CsCDPK genes were identified from the tea plant genome and classified into four phylogenetic groups. These genes were unevenly distributed across 14 chromosomes. Analyses of gene structure, conserved motifs, physicochemical properties, promoter cis-elements, and syntenic relationships indicated that the CsCDPK family is highly conserved but also shows some evolutionary divergence. Expression analyses based on transcriptomic data and RT-qPCR revealed that several CsCDPK genes were strongly induced by infection with the gray blight pathogen Pseudopestalotiopsis spp. and by exogenous salicylic acid (SA) and methyl jasmonate (MeJA) treatments. Endogenous SA, jasmonic acid (JA), and MeJA levels also increased rapidly after pathogen infection. Six genes, CsCDPK3, CsCDPK8, CsCDPK11, CsCDPK12, CsCDPK21, and CsCDPK26, were further functionally analyzed using antisense oligodeoxynucleotide-mediated silencing. Silencing of these genes significantly increased lesion size after pathogen inoculation, indicating reduced resistance. These findings suggest that the selected CsCDPK genes are likely involved in tea plant defense against gray blight disease, providing candidate genes for further functional characterization and potential resistance improvement.

Theacrine (1,3,7,9-tetramethyluric acid) is a purine alkaloid detected in multiple wild and specialised tea germplasms (Camellia sinensis) from South China, including Kucha. However, the molecular mechanisms governing its biosynthesis remain poorly understood. Here, we identify CsTcS2 as a novel theacrine synthase in tea plant. Functional assays involving heterologous expression in Nicotiana benthamiana, antisense oligonucleotide-mediated gene silencing, transient overexpression in tea plants and co-expression with caffeine dehydrogenase (CsCDH) confirm its catalytic role in converting caffeine to theacrine. Transcription factors CsTINY and CsWRKY33 directly bind the CsTcS2 promoter and activate its transcription, as demonstrated by yeast one-hybrid, dual-luciferase reporter and electrophoretic mobility shift assays. Further molecular docking, yeast two-hybrid, bimolecular fluorescence complementation, luciferase complementation, co-immunoprecipitation and antisense inhibition experiments reveal a synergistic interaction between CsTINY and CsWRKY33 that regulates CsTcS2 expression and thus controls theacrine biosynthesis. Together, our findings unravel the transcriptional regulatory network underlying theacrine biosynthesis and provide a molecular foundation for breeding tea cultivars with elevated theacrine levels for health-promoting applications.

Theacrine, a purine alkaloid with pharmacological effects such as calming and anti-depressive activities, is biosynthesized through a key rate-limiting enzyme, caffeine oxidase. Despite its importance, the caffeine oxidase gene (CsCDH) in Camellia sinensis has not been cloned to date. We successfully isolated the full-length CsCDH cDNA, which contains a 501-bp open reading frame (ORF) encoding a 166-amino-acid protein with a calculated molecular weight of 18.7 kDa. Molecular docking and dynamics simulations showed that CsCDH binds tightly and stably to caffeine, indicating its catalytic potential in converting caffeine to 1,3,7-trimethyluric acid. The CsCDH fusion protein was expressed in Escherichia coli and purified through affinity chromatography. In vitro enzymatic assays verified that CsCDH catalyzes the conversion of caffeine into 1,3,7-trimethyluric acid. Furthermore, transient expression in tobacco confirmed its caffeine oxidase activity in planta. Finally, antisense oligonucleotide (asODN) interference experiments confirmed that CsCDH exhibits caffeine oxidase activity in tea plants. This study lays the groundwork for unraveling the theacrine biosynthesis pathway and offers new insights into breeding low-caffeine or high-theacrine tea cultivars.

The PIF7 gene is a member of the bHLH family, playing a pivotal role in plant germination. However, its roles in tea plants (Camellia sinensis) remain largely unexplored. In this study, we cloned the phytochrome-interacting factor gene CsPIF7 to elucidate its role in the germination of tea plants. Subcellular localization analysis demonstrated that CsPIF7 was localized in the nucleus. Yeast one-hybrid and dual-luciferase reporter assays demonstrated that CsPIF7 directly bound to a specific region (7-321 bp) of the CsEXP promoter, thereby repressing the expression of CsEXP. These findings suggest that CsPIF7 may modulate the germination of tea plants by inhibiting the expression of CsEXP. Quantitative real-time PCR results showed that both CsPIF7 and CsEXP exhibited high expression levels in tea buds, with different expression patterns in response to abscisic acid (ABA) treatment. Furthermore, both CsPIF7 and CsEXP were upregulated under cold stress at 4 ℃, indicating their involvement in the cold response of tea plants. Taken together, these results suggest that CsPIF7 regulates CsEXP expression in an ABA-dependent manner, thereby influencing the germination of tea plants. This study provides both theoretical and experimental insights into the molecular mechanisms governing the germination of tea plants, laying the groundwork for further exploring the role of PIF7 in plant development and stress responses.

Drought stress significantly alters the metabolic homeostasis of tea plants; however, few studies have examined the role of specific metabolites, particularly tea polyphenols, in drought resistance. This study reveals that the tea polyphenol content in drought-tolerant tea cultivars tends to increase under drought conditions. Notably, in environments characterized by staged and repeated drought, changes in tea polyphenol are significantly positively correlated with drought resistance. To investigate this further, we irrigated the roots with exogenous tea polyphenols before subjecting the plants to drought. Our findings indicated that the absorptive roots of the experimental group exhibited enhanced development, improved cellular integrity, and a significant increase in peroxidase activity. A comprehensive analysis of the transcriptome and metabolome revealed that tea polyphenols are closely associated with the phenylpropanoid metabolism pathway. Notably, CsMYB77 and CsPOD44 genes were identified as highly correlated with this pathway. Overexpression experiments in Arabidopsis thaliana demonstrated that CsMYB77 promotes the expression of phenylpropanoid pathway genes, thereby enhancing drought resistance. Conversely, antisense oligonucleotide silencing of CsMYB77 decreased drought resistance in tea plants. Additional experiments, including yeast one-hybrid assays, luciferase complementation imaging, dual-luciferase assays, and electrophoretic mobility shift assays, confirmed that CsMYB77 positively regulates the expression of CsPOD44. In summary, our findings indicate that the differences in drought tolerance among tea cultivars are closely linked to phenylpropanoid metabolism. Specifically, tea polyphenols may mediate the regulatory network involving CsMYB77 and CsPOD44, thereby enhancing stress resistance by promoting root development. This study offers new insights into the breeding of drought-resistant tea cultivars.

The PIF7 gene is a member of the bHLH family, playing a pivotal role in plant germination. However, its roles in tea plants (Camellia sinensis) remain largely unexplored. In this study, we cloned the phytochrome-interacting factor gene CsPIF7 to elucidate its role in the germination of tea plants. Subcellular localization analysis demonstrated that CsPIF7 was localized in the nucleus. Yeast one-hybrid and dual-luciferase reporter assays demonstrated that CsPIF7 directly bound to a specific region (7-321 bp) of the CsEXP promoter, thereby repressing the expression of CsEXP. These findings suggest that CsPIF7 may modulate the germination of tea plants by inhibiting the expression of CsEXP. Quantitative real-time PCR results showed that both CsPIF7 and CsEXP exhibited high expression levels in tea buds, with different expression patterns in response to abscisic acid (ABA) treatment. Furthermore, both CsPIF7 and CsEXP were upregulated under cold stress at 4 ℃, indicating their involvement in the cold response of tea plants. Taken together, these results suggest that CsPIF7 regulates CsEXP expression in an ABA-dependent manner, thereby influencing the germination of tea plants. This study provides both theoretical and experimental insights into the molecular mechanisms governing the germination of tea plants, laying the groundwork for further exploring the role of PIF7 in plant development and stress responses.

This study focused on the identification and functional analysis of the F-box-LRR (FBXL) protein family in tea tree (Camellia sinensis), aiming to reveal its role in spring bud germination and environmental adaptation. Thirty-seven members of the tea tree F-box-LRR gene family were identified and systematically analyzed for their chromosomal localization, gene structure, conserved motifs, and cis-acting elements by bioinformatics methods. It was found that these genes were distributed on 14 chromosomes, with strong conserved and inter-gene covariance characteristics. Cis-acting element analysis showed that the F-box-LRR family members were associated with signals such as low temperature, gibberellin and growth hormone, which may play a key role in spring low-temperature germination. In addition, the study verified that the CsWRKY40 transcription factor directly binds to the promoter region of the CsFBXL13 gene and significantly activates its expression by subcellular localization, yeast one-hybridization and dual luciferase assays, revealing the important function of the CsWRKY40-CsFBXL13 regulatory axis in low-temperature response and spring bud germination in tea tree. This study not only expands the understanding of the F-box-LRR protein family, but also provides potential molecular targets for improving the resistance and productivity of tea tree through molecular breeding.

Agrobacterium-mediated transformation is a widely used method for plant genetic modification. However, its efficiency in tea plants is notably low, and the underlying molecular mechanisms remain unclear, hindering advancements in the molecular breeding and biology of tea plants. In this study, tobacco was utilized as a model to investigate the effects of various concentrations of epigallocatechin-3-gallate (EGCG) on Agrobacterium transformation efficiency. The results demonstrated that at an EGCG concentration of 0.4 mg/mL, Agrobacterium nearly lost its ability to transform tobacco. Additionally, malondialdehyde content in Agrobacterium was measured before and after EGCG treatment. The findings indicated that EGCG treatment led to an increase in malondialdehyde content. Transcriptome sequencing analysis revealed that differentially expressed genes (DEGs) involved in Agrobacterium flagellar synthesis and secretion systems were down-regulated under EGCG stress. Furthermore, flgE, virB4, and virB6 were identified as hub genes through weighted gene co-expression network analysis (WGCNA). These results elucidate the dynamic mechanisms by which EGCG affects Agrobacterium at both the physicochemical and molecular levels, providing a theoretical basis for optimizing genetic transformation in tea plants.

Theobromine is an important quality component in tea plants (Camellia sinensis), which is produced from 7-methylxanthine by theobromine synthase (CsTbS), the key rate-limiting enzyme in theobromine biosynthetic pathway. Our transcriptomics and widely targeted metabolomics analyses suggested that CsMYB114 acted as a potential hub gene involved in the regulation of theobromine biosynthesis. The inhibition of CsMYB114 expression using antisense oligonucleotides (ASO) led to a 70.21% reduction of theobromine level in leaves of the tea plant, which verified the involvement of CsMYB114 in theobromine biosynthesis. Furthermore, we found that CsMYB114 was located in the nucleus of the cells and showed the characteristic of a transcription factor. The dual luciferase analysis, a yeast one-hybrid assay, and an electrophoretic mobility shift assay (EMSA) showed that CsMYB114 activated the transcription of CsTbS, through binding to CsTbS promoter. In addition, a microRNA, miR828a, was identified that directly cleaved the mRNA of CsMYB114. Therefore, we conclude that CsMYB114, as a transcription factor of CsTbS, promotes the production of theobromine, which is inhibited by miR828a through cleaving the mRNA of CsMYB114.

Caffeine, a primary flavor component in tea, has been the subject of intense research. With the goal of shedding light on the complex regulatory processes governing caffeine biosynthesis in tea plants, liquid chromatography coupled with mass spectrometry (LC-MS), transcriptomics, and small RNA analyses were employed on diverse tea cultivars such as 'Jianghua Kucha' [including 'Xianghong 3' (XH3H) and 'Kucha 3' (KC3H)], 'Fuding Dabaicha' (FDDB), 'Yaoshan Xiulv' (YSXL), and 'Bixiangzao' (BXZ). The results showed that the caffeine level in 'Jianghua Kucha' was significantly higher than that in other tea plant cultivars. In addition, weighted gene co-expression network analysis indicated that that the CsbHLH1 gene might play a pivotal role as a potential hub gene related to the regulation of caffeine biosynthesis. Subcellular localization analysis showed that the CsbHLH1 protein was localized in the nucleus of the cells. Moreover, CsbHLH1 suppresses the transcription of TCS1 by binding to the TCS1 promoter, as evidenced by a yeast one-hybrid assay, an electrophoretic mobility shift assay, and dual luciferase analysis. In addition, a microRNA, miR1446a, was identified that directly cleaves CsbHLH1, leading to an increase in caffeine levels. Therefore, our findings imply that CsbHLH1 binds to the TCS1 promoter (-971 to -1019 bp) to reduce its expression, thereby negatively regulating caffeine biosynthesis. On the other hand, miR1446a enhances the biosynthesis of caffeine by suppressing the expression of CsbHLH1. This work enhances our understanding of the molecular mechanisms of caffeine biosynthesis in tea plants and offers potential directions for manipulating caffeine levels in future tea cultivation.

NUDIX hydrolase belongs to pyrophosphatase, which plays an important role in information transmission,plant growth coordination and responses to adversity stresses. In this study, 43 NUDIX family genes were identified based on the tea（Camellia sinensis） genome, and analyzed by bioinformatics and fluorescence quantitative PCR. The results show that the protein molecular weight of 43 CsNUDXs rang from 11.8～89.2 kDa, with 102 to 342 amino acids. The theoretical isoelectric point was from 4.49 to 9.26, and 18.6% of them were stable proteins. According to the evolutionary relationship, CsNUDXs is divided into six subfamilies. Cis-acting element analysis of promoter shows that CsNUDXs have many functional elements related to hormone response, adversity stress, growth and development.The expression patterns of CsNUDXs in different organs were analyzed. It was found that the expression levels of CsNUDX3 and CsNUDX7 were high in fruits, while the expression levels of CsNUDX22 and CsNUDX25 were extremely low in fruits, and the expression level of CsNUDX30 was extremely low in old leaves. In addition, the results of real-time fluorescence quantitative PCR show that the expression levels of CsNUDXs, such as CsNUDX1,CsNUDX2 and CsNUDX33 increased first, then decreased and then increased under the treatment of 1 mmol·L -1 MeJA. However, under the treatment of 1 mmol·L -1 SA, the expression levels of CsNUDX4, CsNUDX12 and CsNUDX22 decreased first, then increased and then decreased. While under the treatment of 300 mmol·L -1 NaCl, the expression levels of CsNUDX2, CsNUDX4 and CsNUDX22 increased first and then decreased. In summary, the basic characteristics and functions of CsNUDXs were preliminarily analyzed by bioinformatics technology, and it was found that CsNUDXs could respond to high salt stress, MeJA and SA treatments.

咖啡碱是茶树叶片中的重要化学成分,影响茶叶滋味等品质形成,同时还具有重要药理功能.因此,咖啡碱含量是茶树品种选育的重要考察指标.为提高茶树品种选育效率,实现早期鉴定的目的,本研究首先通过生物信息学分析和鉴定了'铁观音'茶树参考基因组中咖啡碱合成酶基因序列,然后基于咖啡碱合成酶基因TCS(TGY007486),通过基因组DNA测序检测了59份具有不同咖啡碱水平的'黄金茶'群体样本,获得各样本的分子变异数据,最后对变异位点的基因型与咖啡碱含量进行关联分析,获得与咖啡碱含量显著相关的变异位点及其基因型.本研究结果为茶树咖啡碱含量相关的分子标记开发奠定了基础,为茶树分子标记辅助选择育种加速咖啡碱靶向的茶树新品种选育进程提供了新方法.

Background Brassinosteroids (BRs) are a type of sterol plant hormone that play an important role in various biochemical and physiological reactions such as promoting cell growth, increasing biomass, and improving stress resistance. Results To investigate the regulatory and molecular mechanism of BRs on the growth and development of tea plants ( Camellia sinensis L.), changes in cell structure and gene expression levels of tea leaves treated with exogenous BRs were analyzed by electron microscopy and high-throughput Illumina RNA-Seq technology. The results showed that the number of starch granules in the chloroplasts and lipid globules increased and thylakoids expanded after BR treatment compared with the control. Transcriptome analysis showed that in the four BR treatments (CAA: BR treatment for 3 h, CAB: BR treatment for 9 h, CAC: BR treatment for 24 h, and CAD: BR treatment for 48 h), 3861 (1867 upregulated and 1994 downregulated), 5030 (2461 upregulated and 2569 downregulated), 1626 (815 upregulated and 811 downregulated), and 2050 (1004 upregulated and 1046 downregulated) differentially expressed genes were detected, respectively, compared with CAK (BR treatment for 0 h). Using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases, metabolic pathway enrichment analysis showed that the differentially expressed genes of CAA vs. CAK, CAB vs. CAK, CAC vs. CAK, and CAD vs. CAK significantly enriched the functional categories of signal transduction, cell cycle regulation, and starch, sucrose, and flavonoid biosynthesis and metabolism pathways. We also found that after spraying BR, the key genes for caffeine synthesis were downregulated. The results of qRT-PCR coincided with the findings of transcriptomic analysis. Conclusions The present study improved our understanding of the effects of BRs on the growth and development of tea leaves and laid the foundation for the in-depth analysis of signal transduction pathways of BRs in tea leaves.

MYB转录因子广泛参与植物的生长发育、生物以及非生物胁迫的应答过程，为探究茶树Cs MYB81的生物学功能，分析其表达模式。本研究以茶树（Camellia sinensis）品种‘碧香早’为材料，克隆和分析了CsMYB81的cDNA全长序列，对其序列和其编码的氨基酸序列进行了生物信息学分析，利用实时荧光定量PCR检测喷施赤霉素后不同部位的该基因表达水平。结果表明，Cs MYB81全长为1 676 bp，开放阅读框（ORF）全长1 632 bp，编码543个氨基酸，蛋白分子量为59.905 5 kD，等电点为4.99；具有高度保守的R2R3结构域和GAMYB特异性基序（BOX1, BOX2），二级结构预测结果表明CsMYB81蛋白含有螺旋-转角-螺旋（HTH）结构，符合MYB基因家族的结构特征。实时荧光定量PCR分析结果表明Cs MYB81在叶片和茶籽中表达较高，在茎、花和花粉中的表达量较低。对茶树喷施赤霉素（GA3），结果发现当用浓度为10 mmol/L的GA3处理叶片0.5 h时，CsMYB81呈显著表达趋势，推测CsMYB81参与茶树响应赤霉素的过程。本研究为探究茶树CsMYB81的生物学功能提供一定的科学依据，并且茶树CsMYB81在种子中高表达提示该基因可能参与了种子的萌发过程。

Trichomes, which develop from epidermal cells, are considered one of the important characteristics of the tea plant [Camellia sinensis (L.) O. Kuntze]. Many nutritional and metabolomic studies have indicated the important contributions of trichomes to tea products quality. However, understanding the regulation of trichome formation at the molecular level remains elusive in tea plants. Herein, we present a genome-wide comparative transcriptome analysis between the hairless Chuyeqi (CYQ) with fewer trichomes and the hairy Budiaomao (BDM) with more trichomes tea plant genotypes, toward the identification of biological processes and functional gene activities that occur during trichome development. In the present study, trichomes in both cultivars CYQ and BDM were unicellular, unbranched, straight, and soft-structured. The density of trichomes was the highest in the bud and tender leaf periods. Further, using the high-throughput sequencing method, we identified 48,856 unigenes, of which 31,574 were differentially expressed. In an analysis of 208 differentially expressed genes (DEGs) encoding transcription factors (TFs), five may involve in trichome development. In addition, on the basis of the Gene Ontology (GO) annotation and the weighted gene co-expression network analysis (WGCNA) results, we screened several DEGs that may contribute to trichome growth, including 66 DEGs related to plant resistance genes (PRGs), 172 DEGs related to cell wall biosynthesis pathway, 29 DEGs related to cell cycle pathway, and 45 DEGs related to cytoskeleton biosynthesis. Collectively, this study provided high-quality RNA-seq information to improve our understanding of the molecular regulatory mechanism of trichome development and lay a foundation for additional trichome studies in tea plants.