Zhao Qing, Chen Jinliang, Kang Jian, Kang Shaozhong
State Key Laboratory of Efficient Utilization of Agricultural Water Resources, Beijing 100083, China.
National Field Scientific Observation and Research Station on Efficient Water Use of Oasis Agriculture in Wuwei of Gansu Province, Wuwei 733009, China.
Plants (Basel). 2025 Jan 20;14(2):298. doi: 10.3390/plants14020298.
Plants respond to environmental changes by altering the anatomical structure of the xylem and its hydraulic properties. While numerous studies have explored the effects of individual environmental factors on crops, the combined interactions of these factors remain underexplored. As climate change intensifies, the occurrence of salt stress is becoming more frequent, alongside a rise in atmospheric CO concentration. This study aims to investigate the effects of elevated CO and salt stress on the hydraulic traits and xylem anatomical structures of cotton stems. Potted cotton plants were exposed to different CO concentrations (aC: 400 ppm; eC: 800 ppm) and salinity levels (aS: 0‱ soil salinity; eS: 6‱ soil salinity). The study found that under eC and eS conditions, a trade-off exists between hydraulic efficiency and safety in cotton stems, which may be partially attributed to xylem anatomical structures. Specifically, eS significantly reduced stem hydraulic conductivity under aC conditions and decreased vessel diameter but increased the proportion of small-diameter vessels and enhanced implosion resistance ((t/b)), which strengthened the xylem's resistance to salt-induced embolism. eC altered the response pattern of xylem hydraulic conductivity and embolism resistance to salt stress, with increased vessel diameter enhancing hydraulic conductivity but reducing xylem resistance to embolism. These findings enhance our comprehension of plant hydraulic adaptation under future climatic conditions and provide new insights into the trade-offs between xylem structure and function.
植物通过改变木质部的解剖结构及其水力特性来响应环境变化。虽然众多研究探讨了单个环境因素对作物的影响，但这些因素的综合相互作用仍未得到充分研究。随着气候变化加剧，盐胁迫的发生越来越频繁，同时大气中二氧化碳浓度也在上升。本研究旨在探究二氧化碳浓度升高和盐胁迫对棉花茎水力特征及木质部解剖结构的影响。将盆栽棉花植株暴露于不同的二氧化碳浓度（aC：400 ppm；eC：800 ppm）和盐度水平（aS：0‰土壤盐度；eS：6‰土壤盐度）下。研究发现，在eC和eS条件下，棉花茎的水力效率和安全性之间存在权衡，这可能部分归因于木质部解剖结构。具体而言，在aC条件下，eS显著降低了茎的水力传导率，减小了导管直径，但增加了小直径导管的比例并提高了抗爆能力（(t/b)），从而增强了木质部对盐诱导栓塞的抗性。eC改变了木质部水力传导率和栓塞抗性对盐胁迫的响应模式，导管直径增加提高了水力传导率，但降低了木质部对栓塞的抗性。这些发现增强了我们对未来气候条件下植物水力适应性的理解，并为木质部结构与功能之间的权衡提供了新的见解。
