叶膜泄漏和树叶液压故障定义了Cupressus sempervirens干旱引起的树木死亡无回归点
Asaf Alon1,2,3, Shabtai Cohen2, Regis Burlett4
1Institute of Plant Sciences, Volcani Center, Agricultural Research Organization, Rishon LeZion, Israel.
Physiologia plantarum
|August 14, 2024
概括
干旱期间Cupressus sempervirens幼苗的死亡率与膜完整性损失有关,而不仅仅是体栓塞. 这发生在临界水位值达到之前,影响了液压功能.
科学领域:
- 植物生理学 植物生理学
- 干旱压力反应反应干旱压力反应
- 树木死亡机制的机制
背景情况:
- 常春 (Cupressus sempervirens) 具有较高的抗氧体栓塞性,P50约为-10 MPa,具有较高的抗氧体栓塞性.
- 半干旱地区的实地观察表明,死亡率发生在低于预期的栓塞水平.
- 栓塞,液压故障和植物死亡率之间的关系需要进一步研究.
研究的目的:
- 在受控制的干旱条件下,研究Cupressus sempervirens的西栓塞和幼苗死亡率之间的相互作用.
- 为了比较当地的种子来源 (S型) 和抗旱克隆 (C型) 的干旱反应.
主要方法:
- 对S型和C型Cupressus sempervirens种子进行受控干旱实验.
- 测量包括血栓阻力 (P50),叶片相对含水量 (RWC),水潜力,光合作用,电解质泄漏 (EL),水损失,叶片液压导电性和非结构性碳水化合物 (NSC).
- 在整个实验期间,对幼苗的存活率和死亡率进行了监测.
主要成果:
- 两种类型的幼苗死亡率发生在相似的门:52-55%的叶子RWC,55% (S型) 和18.5% (C型) 的导电性损失 (PLC).
- 死亡时的电解质泄漏 (EL) 值为48% (S型) 和37% (C型),表明膜损伤.
- 虽然C型NSC随着干旱而增加,但在活生生的幼苗和死的幼苗之间没有发现NSC的差异.
结论:
- 在Cupressus sempervirens中,幼苗的死亡率与发生在临界体水潜力之前或临界体水潜力之前的膜完整性损失 (用EL表示) 有关.
- 导致死亡的液压故障与超越仅仅栓塞水平的生理值有关.
- 研究结果表明,膜损伤在干旱引起的树木死亡中起着至关重要的作用,这可能解释了现场观测.
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