Department of Biology, Washington University, St. Louis, MO 63130, USA.
Center for Biomolecular Condensates, Washington University, St. Louis, MO 63130, USA.
Development. 2023 Dec 1;150(23). doi: 10.1242/dev.202106. Epub 2023 Nov 30.
In concert with other phytohormones, auxin regulates plant growth and development. However, how auxin and other phytohormones coordinately regulate distinct processes is not fully understood. In this work, we uncover an auxin-abscisic acid (ABA) interaction module in Arabidopsis that is specific to coordinating activities of these hormones in the hypocotyl. From our forward genetics screen, we determine that ABA biosynthesis is required for the full effects of auxin on hypocotyl elongation. Our data also suggest that ABA biosynthesis is not required for the inhibitory effects of auxin treatment on root elongation. Our transcriptome analysis identified distinct auxin-responsive genes in root and shoot tissues, which is consistent with differential regulation of growth in these tissues. Further, our data suggest that many gene targets repressed upon auxin treatment require an intact ABA pathway for full repression. Our results support a model in which auxin stimulates ABA biosynthesis to fully regulate hypocotyl elongation.
与其他植物激素协同作用，生长素调节植物的生长和发育。然而，生长素和其他植物激素如何协调调节不同的过程还不完全清楚。在这项工作中，我们在拟南芥中发现了一个生长素-脱落酸（ABA）相互作用模块，该模块专门协调这些激素在胚轴中的作用。从正向遗传学筛选中，我们确定 ABA 生物合成是生长素对胚轴伸长的全部作用所必需的。我们的数据还表明，ABA 生物合成对于生长素处理对根伸长的抑制作用不是必需的。我们的转录组分析在根和茎组织中鉴定出了不同的生长素反应基因，这与这些组织中生长的差异调节一致。此外，我们的数据表明，许多在生长素处理后被抑制的基因靶标需要一个完整的 ABA 途径来完全抑制。我们的结果支持这样一种模型，即生长素刺激 ABA 生物合成以完全调节胚轴伸长。
