College of Tea Sciences, Guizhou University, Guiyang, 550025, China.
Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), College of Life Sciences/Institute of Agro-Bioengineering, Guizhou University, Guiyang, 550025, China.
Sci Rep. 2024 Nov 19;14(1):28620. doi: 10.1038/s41598-024-80143-5.
Tea plants (Camellia sinensis L.) are prone to spring frosts, leading to substantial economic damage. WRKY transcription factors are key in plant abiotic stress responses, yet the role of CsWRKY29 in freezing tolerance is unclear. In this study, quantitative real-time PCR (qRT-PCR) and transient green fluorescent protein assay revealed that CsWRKY29 localizes to the nucleus and its expression is induced by cold and abscisic acid (ABA). CsWRKY29 overexpression in Arabidopsis enhanced freezing tolerance, reduced electrolyte leakage, increased soluble sugars, and boosted superoxide dismutase activity, with upregulated COR genes. These lines also showed heightened ABA and glucose sensitivity. Cold treatment of CsWRKY29-overexpressing lines upregulated AtABI5, AtHXK1, and AtSUS4 compared to wild type, and yeast one-hybrid assays confirmed CsWRKY29 binding to the W-box in the CsABI5 promoter. Furthermore, the application of virus-induced gene silencing (VIGS) technology to reduce CsWRKY29 expression in tea plants revealed a significant decrease in the transcript levels of CsCBFs, CsABI5, CsHXK1, and CsSUS4 in the silenced plants. In summary, our findings indicate that CsWRKY29 may serve as a critical transcription factor that contributes to freezing tolerance, ABA responsiveness, and sugar metabolism within tea plants.
茶树（Camellia sinensis L.）易受春季霜害影响，导致重大经济损失。WRKY 转录因子在植物非生物胁迫反应中起着关键作用，但 CsWRKY29 在抗冻性中的作用尚不清楚。在本研究中，通过定量实时 PCR（qRT-PCR）和瞬时绿色荧光蛋白测定法表明，CsWRKY29 定位于细胞核，其表达受冷和脱落酸（ABA）诱导。在拟南芥中过表达 CsWRKY29 增强了抗冻性，降低了电解质渗漏，增加了可溶性糖，并提高了超氧化物歧化酶活性，同时 COR 基因上调。这些品系还表现出对 ABA 和葡萄糖的敏感性增强。与野生型相比，CsWRKY29 过表达系在冷处理下上调了 AtABI5、AtHXK1 和 AtSUS4，酵母单杂交实验证实 CsWRKY29 与 CsABI5 启动子中的 W 框结合。此外，应用病毒诱导的基因沉默（VIGS）技术降低茶树中的 CsWRKY29 表达水平，导致沉默植株中 CsCBFs、CsABI5、CsHXK1 和 CsSUS4 的转录水平显著降低。总之，我们的研究结果表明，CsWRKY29 可能作为一个关键的转录因子，在茶树中参与抗冻性、ABA 响应和糖代谢。
