Galindo-Trigo Sergio, Bågman Anne-Maarit, Ishida Takashi, Sawa Shinichiro, Brady Siobhán M, Butenko Melinka A
Section for Genetics and Evolutionary Biology, Department of Biosciences, University of Oslo, Norway.
Department of Plant Biology and Genome Center, University of California, Davis, CA, USA.
J Exp Bot. 2024 Apr 15;75(8):2417-2434. doi: 10.1093/jxb/erae014.
Plants shed organs such as leaves, petals, or fruits through the process of abscission. Monitoring cues such as age, resource availability, and biotic and abiotic stresses allow plants to abscise organs in a timely manner. How these signals are integrated into the molecular pathways that drive abscission is largely unknown. The INFLORESCENCE DEFICIENT IN ABSCISSION (IDA) gene is one of the main drivers of floral organ abscission in Arabidopsis and is known to transcriptionally respond to most abscission-regulating cues. By interrogating the IDA promoter in silico and in vitro, we identified transcription factors that could potentially modulate IDA expression. We probed the importance of ERF- and WRKY-binding sites for IDA expression during floral organ abscission, with WRKYs being of special relevance to mediate IDA up-regulation in response to biotic stress in tissues destined for separation. We further characterized WRKY57 as a positive regulator of IDA and IDA-like gene expression in abscission zones. Our findings highlight the promise of promoter element-targeted approaches to modulate the responsiveness of the IDA signaling pathway to harness controlled abscission timing for improved crop productivity.
植物通过脱落过程脱落叶子、花瓣或果实等器官。诸如年龄、资源可用性以及生物和非生物胁迫等监测线索使植物能够及时脱落器官。这些信号如何整合到驱动脱落的分子途径中在很大程度上尚不清楚。脱落缺陷花序（IDA）基因是拟南芥花器官脱落的主要驱动因素之一，已知其在转录水平上对大多数脱落调节线索作出反应。通过在计算机上和体外研究IDA启动子，我们鉴定出了可能调节IDA表达的转录因子。我们探究了ERF和WRKY结合位点在花器官脱落过程中对IDA表达的重要性，其中WRKYs在介导IDA上调以响应注定要分离的组织中的生物胁迫方面具有特殊相关性。我们进一步将WRKY57鉴定为脱落区中IDA和类IDA基因表达的正调控因子。我们的研究结果突出了针对启动子元件的方法在调节IDA信号通路响应性方面的前景，以便利用可控的脱落时间来提高作物产量。
