Table 1_Transcriptome sequencing revealed the regulation of stem internode length associated with mechanical harvesting in three tea varieties.xlsx

IntroductionInternode length of tea plant is one of the key traits affecting the mechanical harvesting effect, but there are relatively few reports on their molecular regulatory.
MethodsTranscriptome sequencing (RNA-seq) was performed on it in order to explain its molecular mechanism. GO, KEGG enrichment and WGCNA were used to identify key genes, and their expression levels in three tea tree varieties were validated by qRT-PCR.
ResultIn this study, we measured the internode lengths of the three varieties and found that their internode lengths were ‘Feiyun’ > ‘Qiancha 1’ > ‘Longjing 43’. 10,518 differentially expressed genes were identified through transcriptome sequencing and analysis. GO and KEGG enrichment showed that these differentially expressed genes were mainly enriched in plant hormone signal transduction and DNA-binding transcription factor activity pathways. WGCNA analysis identified two modules significantly correlated with internode length. Combining enrichment analysis with WGCNA results, 28 candidate genes associated with internode length were identified. In addition, it was found that the expression levels of DELLA and GA3ox were highly expressed in ‘Longjing 43’, while GA2ox, WRKY, and ERF were highly expressed in ‘Feiyun’, showing significant positive and negative correlations with internode length, respectively.
DiscussionOur results provide candidate genes for studying the molecular mechanism of stem elongation, and provide a theoretical basis for selection machine harvested tea varieties and improvement of mechanical harvesting efficiency.

引言
茶树节间长度是影响机械采收效果的关键性状之一，但目前针对其分子调控机制的相关研究报道相对较少。
方法
为阐明其分子调控机制，本研究对样本开展转录组测序（RNA-seq）。通过GO富集分析、KEGG富集分析及加权基因共表达网络分析（WGCNA）筛选关键基因，并采用实时荧光定量PCR（qRT-PCR）验证3个茶树品种中关键基因的表达水平。
结果
本研究测定了3个茶树品种的节间长度，结果显示节间长度由高到低依次为‘飞云’＞‘黔茶1号’＞‘龙井43’。通过转录组测序与分析，共鉴定得到10518个差异表达基因。GO和KEGG富集分析结果表明，这些差异表达基因主要富集于植物激素信号转导及DNA结合转录因子活性通路。WGCNA分析筛选得到2个与节间长度显著相关的基因模块。结合富集分析与WGCNA分析结果，最终鉴定得到28个与节间长度相关的候选基因。此外，研究发现DELLA与GA3ox在‘龙井43’中呈高表达，而GA2ox、WRKY及ERF在‘飞云’中呈高表达，其表达水平分别与节间长度呈显著正相关与负相关。
讨论
本研究结果为茎伸长的分子调控机制研究提供了候选基因，同时为适宜机械采收的茶树品种选育及机械采收效率提升提供了理论依据。