Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB, Bellaterra, 08193, Barcelona, Spain.
Department of Plant Systems Biology, Department of Plant Biotechnology and Bioinformatics, Flanders Institute for Biotechnology, Ghent University, 9052, Ghent, Belgium.
New Phytol. 2023 Aug;239(4):1281-1299. doi: 10.1111/nph.19022. Epub 2023 Jun 15.
Increasing drought phenomena pose a serious threat to agricultural productivity. Although plants have multiple ways to respond to the complexity of drought stress, the underlying mechanisms of stress sensing and signaling remain unclear. The role of the vasculature, in particular the phloem, in facilitating inter-organ communication is critical and poorly understood. Combining genetic, proteomic and physiological approaches, we investigated the role of AtMC3, a phloem-specific member of the metacaspase family, in osmotic stress responses in Arabidopsis thaliana. Analyses of the proteome in plants with altered AtMC3 levels revealed differential abundance of proteins related to osmotic stress pointing into a role of the protein in water-stress-related responses. Overexpression of AtMC3 conferred drought tolerance by enhancing the differentiation of specific vascular tissues and maintaining higher levels of vascular-mediated transportation, while plants lacking the protein showed an impaired response to drought and inability to respond effectively to the hormone abscisic acid. Overall, our data highlight the importance of AtMC3 and vascular plasticity in fine-tuning early drought responses at the whole plant level without affecting growth or yield.
日益增多的干旱现象对农业生产力构成了严重威胁。尽管植物有多种方法来应对复杂的干旱胁迫，但胁迫感应和信号转导的潜在机制仍不清楚。脉管系统，特别是韧皮部，在促进器官间通讯方面的作用至关重要，但却知之甚少。本研究结合遗传、蛋白质组学和生理学方法，研究了拟南芥中韧皮部特异性 metacaspase 家族成员 AtMC3 在渗透胁迫反应中的作用。对 AtMC3 水平改变的植物的蛋白质组分析揭示了与渗透胁迫相关的蛋白质的丰度差异，表明该蛋白在与水胁迫相关的反应中发挥作用。AtMC3 的过表达通过增强特定维管束组织的分化和维持更高水平的维管束介导的运输来赋予耐旱性，而缺乏该蛋白的植物对干旱的反应受损，并且无法有效响应激素脱落酸。总体而言，我们的数据强调了 AtMC3 和血管可塑性在精细调节整个植物水平早期干旱反应方面的重要性，而不会影响生长或产量。
