Members of the bacterial genus Azospirillum are root‐associated bacteria that increase yield in cereals by promoting growth and alleviating drought stress. How plants integrate the many bacterium‐derived growth‐promoting stimuli with other environmental factors to generate a coordinated response remains unresolved. Using a commercial Azospirillum strain, A. lipoferum CRT1 and two host maize cultivars, it was observed that bacterization reduced the drought‐induced increase in lateral root growth and enhanced the flood‐induced increase in lateral root growth in the more drought‐ and flood‐sensitive cultivar. In the other one, A. lipoferum CRT1 only elicited a moderate root growth response under low soil water potential. The photosynthetic potential and activity were increased in the earlier cultivar and decreased in the later one, irrespective of the soil water content. No impact of the bacterium was seen on the growth of the leaves of both cultivars under both stresses until the third leaf stage, therefore suggesting that it is a consequence of multiple primary adaptations to biotic and abiotic stresses. It is suggested that host–bacteria recognition leads to a stress‐specific modulation of the root response and a differential stress‐independent effect on photosynthesis. This is the first report of the impact of Azospirillum under flood conditions.

中文翻译：

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土壤水分对玉米对植物促根瘤菌脂铁螺旋藻CRT1响应的影响

固氮螺旋菌属的细菌是与根相关的细菌，通过促进生长和缓解干旱胁迫而增加谷物的产量。植物如何将许多细菌来源的促进生长的刺激与其他环境因素整合，以产生协调的反应尚待解决。使用商业固氮螺菌菌株，A. lipoferum CRT1和两个主机玉米品种，可以观察到bacterization减少在侧根生长干旱诱导增加和增强侧根生长洪水诱导增加更多干旱和洪灾敏感品种。在另一种中，A.lipoferum在低土壤水势下，CRT1仅引起中等程度的根系生长响应。不论土壤含水量如何，早期品种的光合作用潜力和活性增加，而后期品种则降低。直到第三个叶期，在两种胁迫下都没有观察到细菌对两个品种叶片的生长的影响，因此表明这是对生物和非生物胁迫进行多次主要适应的结果。建议宿主细菌的识别导致根响应的胁迫特异性调节，以及对光合作用的胁迫依赖性差异作用。这是关于满天星螺旋藻在洪水条件下影响的第一份报告。