Bharadwaj Priyanka S, Sanchez Lizbeth, Li Dongdong, Enyi Divine, Van de Poel Bram, Chang Caren
Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, United States.
Division of Crop Biotechnics, Department of Biosystems, University of Leuven, Leuven, Belgium.
Front Plant Sci. 2022 Oct 18;13:998267. doi: 10.3389/fpls.2022.998267. eCollection 2022.
Plants are often faced with an array of adverse environmental conditions and must respond appropriately to grow and develop. In angiosperms, the plant hormone ethylene is known to play a protective role in responses to abiotic stress. Here we investigated whether ethylene mediates resistance to abiotic stress in the liverwort , one of the most distant land plant relatives of angiosperms. Using existing knockout mutants of Mp, and Mp, two genes in the ethylene signaling pathway, we examined responses to heat, salinity, nutrient deficiency, and continuous far-red light. The Mp and Mp mutants were previously shown to confer ethylene insensitivity and constitutive ethylene responses, respectively. Using mild or sub-lethal doses of each stress treatment, we found that Mp mutants displayed stress resilience similar to or greater than the wild type. In contrast, Mp mutants showed less resilience than the wild type. Consistent with ethylene being a stress hormone, we demonstrated that ethylene production is enhanced by each stress treatment. These results suggest that ethylene plays a role in protecting against abiotic stress in , and that ethylene has likely been conserved as a stress hormone since before the evolutionary divergence of bryophytes from the land plant lineage approximately 450 Ma.
植物常常面临一系列不利的环境条件，必须做出适当反应才能生长和发育。在被子植物中，已知植物激素乙烯在对非生物胁迫的反应中起保护作用。在这里，我们研究了乙烯是否介导了地钱（被子植物最遥远的陆地植物亲属之一）对非生物胁迫的抗性。利用乙烯信号通路中两个基因Mp和Mp的现有敲除突变体，我们检测了对热、盐度、营养缺乏和持续远红光的反应。先前已表明，Mp突变体分别表现出乙烯不敏感性和组成型乙烯反应。使用每种胁迫处理的温和或亚致死剂量，我们发现Mp突变体表现出与野生型相似或更强的胁迫恢复力。相比之下，Mp突变体的恢复力比野生型弱。与乙烯作为一种胁迫激素一致，我们证明每种胁迫处理都会增强乙烯的产生。这些结果表明，乙烯在保护地钱免受非生物胁迫中起作用，并且自大约4.5亿年前苔藓植物从陆地植物谱系进化分化之前，乙烯可能就一直作为一种胁迫激素被保留下来。
