Qiao Hualiang, Liu Yongwei, Cheng Lingling, Gu Xuelin, Yin Pengcheng, Li Ke, Zhou Shuo, Wang Geng, Zhou Chunjiang
Ministry of Education Key Laboratory of Molecular and Cell Biology, Hebei Innovation Center for Cell Signaling, College of Life Sciences, Hebei Normal University, Shijiazhuang, China.
Institute of Genetics and Physiology, Hebei Academy of Agriculture and Forestry Sciences/Plant Genetic Engineering Center of Hebei Province, Shijiazhuang, China.
Front Plant Sci. 2021 Sep 1;12:717233. doi: 10.3389/fpls.2021.717233. eCollection 2021.
Leaf senescence is crucial for crop yield and quality. Transcriptional regulation is a key step for integrating various senescence-related signals into the nucleus. However, few regulators of senescence implicating transcriptional events have been functionally characterized in wheat. Based on our RNA-seq data, we identified a WRKY transcription factor, TaWRKY13-A, that predominately expresses at senescent stages. By using the virus-induced gene silencing (VIGS) method, we manifested impaired transcription of leading to a delayed leaf senescence phenotype in wheat. Moreover, the overexpression () of accelerated the onset of leaf senescence under both natural growth condition and darkness in and . Furthermore, by physiological and molecular investigations, we verified that TaWRKY13-A participates in the regulation of leaf senescence jasmonic acid (JA) pathway. The expression of JA biosynthetic genes, including , was altered in -overexpressing . We also demonstrated that TaWRKY13-A can interact with the promoter of and by using the electrophoretic mobility shift assay (EMSA) and luciferase reporter system. Consistently, we detected a higher JA level in -overexpressing lines than that in Col-0. Moreover, our data suggested that TaWRKY13-A is partially functional conserved with AtWRKY53 in age-dependent leaf senescence. Collectively, this study manifests TaWRKY13-A as a positive regulator of JA-related leaf senescence, which could be a new clue for molecular breeding in wheat.
叶片衰老对作物产量和品质至关重要。转录调控是将各种衰老相关信号整合到细胞核中的关键步骤。然而，在小麦中，很少有涉及转录事件的衰老调节因子在功能上得到表征。基于我们的RNA测序数据，我们鉴定了一个WRKY转录因子TaWRKY13-A，它在衰老阶段大量表达。通过使用病毒诱导基因沉默（VIGS）方法，我们发现TaWRKY13-A的转录受损，导致小麦叶片衰老表型延迟。此外，TaWRKY13-A的过表达在拟南芥和小麦的自然生长条件和黑暗条件下均加速了叶片衰老的开始。此外，通过生理和分子研究，我们证实TaWRKY13-A参与了茉莉酸（JA）途径对叶片衰老的调控。在TaWRKY13-A过表达植株中，包括LOX2在内的JA生物合成基因的表达发生了改变。我们还通过电泳迁移率变动分析（EMSA）和荧光素酶报告系统证明TaWRKY13-A可以与LOX2和AOS的启动子相互作用。一致地，我们在TaWRKY13-A过表达株系中检测到比Col-0更高的JA水平。此外，我们的数据表明TaWRKY13-A在年龄依赖性叶片衰老中与AtWRKY53部分功能保守。总的来说，这项研究表明TaWRKY13-A是JA相关叶片衰老的正调控因子，这可能为小麦分子育种提供新的线索。
