Ministry of Education Key Laboratory of Molecular and Cell Biology, Hebei Collaboration Innovation Center for Cell Signaling, College of Life Sciences, Hebei Normal University, Shijiazhuang, China.
Hebei Key Laboratory of Chinese Medicine Research on Cardio-Cerebrovascular Disease, Hebei University of Chinese Medicine, Shijiazhuang, China.
Plant Biol (Stuttg). 2020 Nov;22(6):1072-1085. doi: 10.1111/plb.13155. Epub 2020 Jul 29.
Leaf senescence is a complex and precise regulatory process that is correlated with numerous internal and environmental factors. Leaf senescence is tightly related to the redistribution of nutrients, which significantly affects productivity and quality, especially in crops. Evidence shows that the mediation of transcriptional regulation by WRKY transcription factors is vital for the fine-tuning of leaf senescence. However, the underlying mechanisms of the involvement of WRKY in leaf senescence are still unclear in wheat. Using RNA sequencing data, we isolated a novel WRKY transcription factor, TaWRKY40-D, which localizes in the nucleus and is basically induced by the progression of leaf senescence. TaWRKY40-D is a promoter of natural and dark-induced leaf senescence in transgenic Arabidopsis thaliana and wheat. We also demonstrated a positive response of TaWRKY40-D in wheat upon jasmonic acid (JA) and abscisic acid (ABA) treatment. Consistent with this, the detached leaves of TaWRKY40-D VIGS (virus-induced gene silencing) wheat plants showed a stay-green phenotype, while TaWRKY40-D overexpressing Arabidopsis plants showed premature leaf senescence after JA and ABA treatment. Moreover, our results revealed that TaWRKY40-D positively regulates leaf senescence, possibly by altering the biosynthesis and signalling of JA and ABA pathway genes. Together, our results suggest a new regulator of JA- and ABA-related leaf senescence, as well as a new candidate gene that can be used for molecular breeding in wheat.
叶片衰老是一个复杂而精确的调控过程，与许多内部和环境因素有关。叶片衰老与养分的再分配密切相关，这对作物的生产力和品质有重大影响。有证据表明，WRKY 转录因子对转录调控的介导对精细调控叶片衰老至关重要。然而，WRKY 参与小麦叶片衰老的潜在机制仍不清楚。我们利用 RNA 测序数据分离出一个新的 WRKY 转录因子 TaWRKY40-D，它定位于细胞核中，基本是由叶片衰老的进程诱导的。TaWRKY40-D 是拟南芥和小麦中自然和暗诱导叶片衰老的启动子。我们还证明 TaWRKY40-D 在小麦中对茉莉酸（JA）和脱落酸（ABA）处理有正向响应。与此一致的是，TaWRKY40-D VIGS（病毒诱导基因沉默）小麦叶片的离体叶片表现出绿叶保持的表型，而 TaWRKY40-D 过表达的拟南芥在 JA 和 ABA 处理后表现出过早的叶片衰老。此外，我们的结果表明，TaWRKY40-D 正向调控叶片衰老，可能是通过改变 JA 和 ABA 途径基因的生物合成和信号转导。总之，我们的结果表明 TaWRKY40-D 是 JA 和 ABA 相关叶片衰老的一个新的调节剂，也是小麦分子育种的一个新的候选基因。
