Silva-E-Costa Juliana da C, Luizi-Ponzo Andrea P, McLetchie David Nicholas
Department of Botany, Federal University of Juiz de Fora, Juiz de Fora 36036-900, MG, Brazil.
Department of Biology, University of Kentucky, Lexington, KY 40506-0225, USA.
Plants (Basel). 2022 Feb 10;11(4):478. doi: 10.3390/plants11040478.
Water scarcity, a common stress factor, negatively impacts plant performance. Strategies to cope with it, such as desiccation tolerance, are becoming increasingly important to investigate. However, phenomena, such as intraspecific variation in stress responses have not received much attention. Knowledge of this variability and the environmental drivers can be leveraged to further investigate the mechanisms of desiccation tolerance. Here we tested for variation in desiccation tolerance in among colonies and sexes within the same riparian zone. Field-collected dehardened plants were subjected to a desiccation event, under controlled conditions and then rehydrated. Plant water status, photosynthetic rates, net carbon gain, and efficiency of photosystem II (PSII) were assayed to evaluate tissue desiccation, basic metabolic processes and plant recovery. To establish a linkage between plant response and environmental factors, field light conditions were measured. We detected intraspecific variation, where a more exposed colony (high percentage of open sky, large temporal range of light quantity, and high red/far-red ratio) showed sex differences in desiccation tolerance and recovery. Overall, PSII recovery occurred by 72 h after rehydration, with a positive carbon gain occurring by day 30. This within species variation suggests plastic or genetic effects, and likely association with light conditions.
水资源短缺是一种常见的胁迫因素，会对植物生长产生负面影响。应对水资源短缺的策略，如耐旱性，正变得越来越重要，值得深入研究。然而，种内胁迫反应的差异等现象并未得到太多关注。了解这种变异性及其环境驱动因素有助于进一步探究耐旱性机制。在此，我们测试了同一河岸带内不同群落和性别的耐旱性差异。在可控条件下，对野外采集的已脱硬化植株进行干旱处理，随后再进行复水。测定了植株的水分状况、光合速率、净碳增益以及光系统II（PSII）的效率，以评估组织脱水、基本代谢过程和植株恢复情况。为了建立植物反应与环境因素之间的联系，我们测量了野外光照条件。我们检测到种内差异，即一个受光更多的群落（天空开阔百分比高、光量的时间范围大、红/远红比率高）在耐旱性和恢复能力上存在性别差异。总体而言，复水72小时后PSII恢复，到第30天出现正碳增益。这种种内变异表明存在可塑性或遗传效应，并且可能与光照条件有关。
