Photosynthetic limitations in response to water stress and recovery in Mediterranean plants with different growth forms
Photosynthetic limitations in response to water stress and recovery in Mediterranean plants with different growth forms
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DOI：
10.1111/j.1469-8137.2007.02087.x
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发表时间：
2007-01-01
期刊：
影响因子：
9.4
通讯作者：
Flexas, Jaume
中科院分区：
文献类型：
--
作者：
Galmes, Jeroni;Medrano, Hipolito;Flexas, Jaume
光合作用是否是有限的，因为扩散或生物化学因素在水分胁迫和恢复仍然是有争议的，并出现明显的矛盾时，对不同的生长形式的物种的各种研究进行了比较。10个地中海物种，代表不同的生长形式，受到不同程度的水分胁迫，最严重的其次是复水。采用定量限制分析方法，研究了水分胁迫对C3植物气孔导度（S-L）、叶肉导度（MCL）和生化限制（B-L）的影响，结果表明，以气孔导度（g（s））为参考参数，C3植物光合作用对水分胁迫的响应具有普遍性。随着g（s）值从最大值降至约0.05 molH_2O m（-2）s（-1）时，总光合限制由0上升到约1000. 70%，这是由S-L和MCL限制的逐渐增加引起的，而B-L仍然可以忽略不计。当g（s）值较低时（总光合限制从70%增加到100%），S-L的贡献下降，而MCL仍在增加，B-L对总限制的贡献显著（20-50%）。
Whether photosynthesis is limited during water stress and recovery because of diffusive or biochemical factors is still open to debate, and apparent contradictions appear when various studies on species with different growth forms are compared.Ten Mediterranean species, representing different growth forms, were subjected to different levels of water stress, the most severe followed by rewatering. A quantitative limitation analysis was applied to estimate the effects of water stress on stomatal (S-L), mesophyll conductance (MCL) and biochemical limitations (B-L).Results confirmed a general pattern of photosynthetic response to water stress among C-3 plants when stomatal conductance (g(s)) is used as a reference parameter. As g(s) values decreased from a maximum to approx. 0.05 mol H2O m(-2) s(-1), the total photosynthetic limitation rose from 0 to approx. 70%, and this was caused by a progressive increase of both S-L and MCL limitations, while B-L remained negligible. When lower values of g(s) were achieved (total photosynthetic limitation increased from 70 to 100%), the contribution of S-L declined, while MCL still increased and B-L contributed significantly (20-50%) to the total limitation.Photosynthetic recovery of severely stressed plants after rewatering showed a dominant role of MCL, irrespective of the degree of photosynthesis recovery.