Housh Alexandra Bauer, Noel Randi, Powell Avery, Waller Spenser, Wilder Stacy L, Sopko Stephanie, Benoit Mary, Powell Garren, Schueller Michael J, Ferrieri Richard A
Missouri Research Reactor Center, University of Missouri, Columbia, MO 65211, USA.
Chemistry Department, University of Missouri, Columbia, MO 65211, USA.
Microorganisms. 2023 Jun 30;11(7):1727. doi: 10.3390/microorganisms11071727.
As the use of microbial inoculants in agriculture rises, it becomes important to understand how the environment may influence microbial ability to promote plant growth. This work examines whether there are light dependencies in the biological functions of , a commercialized prolific grass-root colonizer. Though classically defined as non-phototrophic, possesses photoreceptors that could perceive light conducted through its host's roots. Here, we examined the light dependency of atmospheric biological nitrogen fixation (BNF) and auxin biosynthesis along with supporting processes including ATP biosynthesis, and iron and manganese uptake. Functional mutants of were studied in light and dark environments: HM053 (high BNF and auxin production), (capable of BNF, deficient in auxin production), and FP10 (capable of auxin production, deficient in BNF). HM053 exhibited the highest rate of nitrogenase activity with the greatest light dependency comparing iterations in light and dark environments. The mutant showed similar behavior with relatively lower nitrogenase activity observed, while FP10 did not show a light dependency. Auxin biosynthesis showed strong light dependencies in HM053 and FP10 strains, but not for . Ferrous iron is involved in BNF, and a light dependency was observed for microbial Fe uptake in HM053 and , but not FP10. Surprisingly, a light dependency for Mn uptake was only observed in . Finally, ATP biosynthesis was sensitive to light across all three mutants favoring blue light over red light compared to darkness with observed ATP levels in descending order for HM053 > > FP10.
随着农业中微生物接种剂的使用增加，了解环境如何影响微生物促进植物生长的能力变得很重要。这项工作研究了一种商业化的多产草根定殖菌在生物学功能上是否存在对光的依赖性。尽管传统上被定义为非光养型，但该菌拥有能够感知通过其宿主根系传导的光的光感受器。在这里，我们研究了大气生物固氮（BNF）和生长素生物合成的光依赖性以及包括ATP生物合成、铁和锰吸收在内的支持过程。在光照和黑暗环境中研究了该菌的功能突变体：HM053（高BNF和生长素产生）、（能够进行BNF，生长素产生缺陷）和FP10（能够产生生长素，BNF缺陷）。与光照和黑暗环境中的迭代相比，HM053表现出最高的固氮酶活性和对光的最大依赖性。突变体表现出类似的行为，观察到的固氮酶活性相对较低，而FP10没有表现出对光的依赖性。生长素生物合成在HM053和FP10菌株中表现出强烈的光依赖性，但在中没有。亚铁参与BNF，在HM053和中观察到微生物对铁的吸收存在光依赖性，但在FP10中没有。令人惊讶的是，仅在中观察到对锰吸收的光依赖性。最后，在所有三个突变体中，ATP生物合成对光敏感，与黑暗相比，蓝光比红光更有利于ATP生物合成，观察到的ATP水平按HM053 > > FP10的顺序递减。
