Plant Stress Resilience, Institute of Environmental Biology, Utrecht University, Utrecht, The Netherlands.
Evolutionary Plant Ecophysiology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands.
Plant Cell Environ. 2024 Nov;47(11):4464-4480. doi: 10.1111/pce.15033. Epub 2024 Jul 16.
Flooding events are highly detrimental to most terrestrial plant species. However, there is an impressive diversity of plant species that thrive in flood-prone regions and represent a treasure trove of unexplored flood-resilience mechanisms. Here we surveyed a panel of four species from the Cardamineae tribe representing a broad tolerance range. This included the flood-tolerant Cardamine pratensis, Rorippa sylvestris and Rorippa palustris and the flood-sensitive species Cardamine hirsuta. All four species displayed a quiescent strategy, evidenced by the repression of shoot growth underwater. Comparative transcriptomics analyses between the four species and the sensitive model species Arabidopsis thaliana were facilitated via de novo transcriptome assembly and identification of 16 902 universal orthogroups at a high resolution. Our results suggest that tolerance likely evolved separately in the Cardamine and Rorippa species. While the Rorippa response was marked by a strong downregulation of cell-cycle genes, Cardamine minimized overall transcriptional regulation. However, a weak starvation response was a universal trait of tolerant species, potentially achieved in multiple ways. It could result from a strong decline in cell-cycle activity, but is also intertwined with autophagy, senescence, day-time photosynthesis and night-time fermentation capacity. Our data set provides a rich source to study adaptational mechanisms of flooding tolerance.
洪水事件对大多数陆生植物物种都有极大的危害。然而，有许多植物物种在洪水泛滥的地区茁壮成长，它们代表了一个尚未探索的抗洪水机制宝库。在这里，我们调查了来自于荠属（Cardamineae）四个物种的样本，它们代表了广泛的耐受范围。这包括耐洪水的荠（Cardamine pratensis）、山苦荬（Rorippa sylvestris）、沼生蔊菜（Rorippa palustris）和洪水敏感物种毛果蔊菜（Cardamine hirsuta）。所有四个物种都表现出一种休眠策略，表现为水下抑制芽的生长。通过从头转录组组装和在高分辨率下鉴定 16902 个通用直系同源物，促进了这四个物种与敏感模式物种拟南芥（Arabidopsis thaliana）之间的比较转录组学分析。我们的结果表明，在荠属和蔊菜属物种中，耐受性可能是分别进化而来的。虽然蔊菜属的反应以细胞周期基因的强烈下调为标志，但荠属则最小化了整体转录调控。然而，弱饥饿反应是耐受物种的普遍特征，可能通过多种方式实现。它可能是由于细胞周期活性的强烈下降，但也与自噬、衰老、白天光合作用和夜间发酵能力交织在一起。我们的数据集为研究洪水耐受适应性机制提供了丰富的资源。
