Abstract Jatropha curcas plants were cultivated during 4 months in pots containing soil at 90% of field capacity (FC), in permanent drought at 30% of FC and in extreme drought without any irrigation. The permanent drought clearly resulted in significant reductions of 43% on spongy parenchyma thickness and increase of 170% on stomatal index and 80% in photosynthetic pigments content. The measurements of leaf gas showed that growing in permanent drought condition resulted in decreases of 38% on net CO2 assimilation rate, 81% on stomatal conductance, 69% on transpiration, 30% on intercellular carbon concentration (Ci) and reductions on the capacity to refresh leaves. The plants subjected to extreme drought took a period of 12 days of re-irrigation to recover values of CO2 assimilation and stomatal conductance similar to well-irrigated plants. Some of these morphophysiological changes look as though not to directly result from drought, but from secondary variations unleashed by stomatal closure and intensified by long duration of stressful conditions. This seems to result in plants photosynthetically more efficient with competitive advantage in arid situations. Besides these variations, it was possible to show and evaluate the resilience and extreme tolerance of these plants to survive in harsh environment.

中文翻译：

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麻风树长期干旱引起的叶片形态生理变化解释了对极端干旱的恢复能力

摘要 麻疯树植物在含有 90% 田间持水量 (FC) 土壤的盆中、在 30% FC 的永久性干旱和没有任何灌溉的极端干旱中栽培 4 个月。永久性干旱明显导致海绵状薄壁组织厚度显着减少 43%，气孔指数增加 170%，光合色素含量增加 80%。叶气测量表明，在永久性干旱条件下生长导致净 CO2 同化率降低 38%，气孔导度降低 81%，蒸腾作用降低 69%，细胞间碳浓度 (Ci) 降低 30%，并降低吸收二氧化碳的能力。刷新叶子。遭受极端干旱的植物需要 12 天的重新灌溉时间才能恢复与灌溉良好的植物相似的 CO2 同化值和气孔导度值。其中一些形态生理变化看起来似乎不是由干旱直接引起的，而是由气孔关闭释放的次生变化引起的，并因长期的压力条件而加剧。这似乎导致植物在干旱情况下的光合作用效率更高，具有竞争优势。除了这些变化之外，还可以展示和评估这些植物在恶劣环境中生存的弹性和极端耐受性。