Wang Lu, Wang Guilin, Wang Feifei, Chen Zhiguo, Wang Xinyu, Guo Wangzhen
State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China; Engineering Research Center of Ministry of Education for Cotton Germplasm Enhancement and Application, Nanjing Agricultural University, Nanjing 210095, China.
College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.
Plant Sci. 2025 Oct;359:112663. doi: 10.1016/j.plantsci.2025.112663. Epub 2025 Jul 9.
As a family of plant-specific transcription factors, the TEOSINTE BRANCHED 1, CYCLOIDEA, and PROLIFERATING CELL FACTOR (TCP) family plays a pivotal role in biotic stress responses. Verticillium dahliae, a devastating soil-borne fungal pathogen, causes severe vascular wilt in numerous crops. Several studies have reported that TCPs modulate defense signaling against various pathogens, while their molecular mechanisms in regulating the resistance to V. dahliae remain poorly characterized. In this study, we identified a TCP transcription factor in Gossypium barbadense acc. Hai7124, GbTCP20, that positively regulates V. dahliae resistance. The transcript level of GbTCP20 was significantly upregulated upon V. dahliae attack. Silencing GbTCP20 compromised the cotton resistance to V. dahliae, while overexpressing GbTCP20 in Arabidopsis significantly enhanced plant wilt resistance. Cis-acting element analysis of promoters from differentially expressed genes obtained by comparing root transcriptomes between GbTCP20-silenced and control plants, identified GbERF4 and GbCOMT as candidate downstream genes of GbTCP20, which GbERF4 encodes an AP2/ERF transcription factor involved in modulating 1-aminocyclopropane-1-carboxylic acid (ACC) biosynthesis pathway, and GbCOMT encodes caffeic acid O-methyltransferase, a pivotal enzyme in the lignin biosynthesis pathway. The Dual-Luciferase reporter assay confirmed that GbTCP20 enhances GbERF4 and GbCOMT expression via direct binding to their promoters. Overexpressing GbTCP20 in Arabidopsis elevated the expression of AtERF4, leading to increased AtACS2 and AtACS6 transcript level. Silencing GbTCP20 in G. barbadense acc. Hai7124 inhibited the expression of GbCOMT, leading to decreased lignin content in the stem. Our study reveals that GbTCP20 confers dual defense strategies against Verticillium wilt through both ACC-mediated chemical defense and lignin-based physical barriers in cotton.
作为植物特有的转录因子家族，TEOSINTE BRANCHED 1、CYCLOIDEA和PROLIFERATING CELL FACTOR（TCP）家族在生物胁迫反应中起关键作用。大丽轮枝菌是一种具有毁灭性的土传真菌病原体，可导致多种作物严重的维管束萎蔫病。多项研究报道，TCPs可调节针对各种病原体的防御信号传导，但其调节对大丽轮枝菌抗性的分子机制仍不清楚。在本研究中，我们在海岛棉（Gossypium barbadense）品种Hai7124中鉴定出一个TCP转录因子GbTCP20，它正向调节对大丽轮枝菌的抗性。在受到大丽轮枝菌攻击后，GbTCP20的转录水平显著上调。沉默GbTCP20会削弱棉花对大丽轮枝菌的抗性，而在拟南芥中过表达GbTCP20则显著增强了植物的萎蔫抗性。通过比较GbTCP20沉默植株和对照植株的根系转录组，对差异表达基因的启动子进行顺式作用元件分析，确定GbERF4和GbCOMT为GbTCP20的候选下游基因，其中GbERF4编码一种参与调节1-氨基环丙烷-1-羧酸（ACC）生物合成途径的AP2/ERF转录因子，GbCOMT编码咖啡酸O-甲基转移酶，这是木质素生物合成途径中的一种关键酶。双荧光素酶报告基因检测证实，GbTCP20通过直接结合GbERF4和GbCOMT的启动子来增强它们的表达。在拟南芥中过表达GbTCP20可提高AtERF4的表达，导致AtACS2和AtACS6转录水平增加。在海岛棉品种Hai7124中沉默GbTCP20会抑制GbCOMT的表达，导致茎中木质素含量降低。我们的研究表明，GbTCP20通过ACC介导的化学防御和基于木质素的物理屏障，赋予棉花对黄萎病的双重防御策略。
