PSC, Shanghai Center for Plant Stress Biology, and CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China.
Institute for Water Research and Department of Microbiology, University of Granada, Granada, Spain.
Plant Signal Behav. 2020 Apr 2;15(4):1740872. doi: 10.1080/15592324.2020.1740872. Epub 2020 Mar 17.
Plant growth-promoting rhizobacteria (PGPR) are naturally occurring soil microorganisms that colonize roots and stimulate plant growth. Some PGPR strains can directly regulate plant growth in the absence of physical contact with the plant, via volatile organic compounds (VOCs) emissions. Recently, we have described that respond differentially to diacetyl, a VOC from strain GB03 (GB03), through integral modulation of the immune system and the phosphate-starvation response (PSR) system, resulting in either mutualism or immunity. Under phosphate deficient conditions, diacetyl enhances salicylic acid- and jasmonic acid-mediated immunity and consequently causes plant hyper-sensitivity to phosphate deficiency. Here, we show that application of exogenous gibberellin (GA) partially alleviates the deleterious effect caused by either GB03 VOCs or diacetyl in under phosphate deficient conditions, while DELLA quadruple mutant exposed to GB03 VOCs exhibits a partial reduction on the stress symptoms. Moreover, diacetyl appears to enhance DELLA protein accumulation and increase the expression of several GA deactivation-related genes. These findings suggest that the DELLA-mediated GA signaling pathway is involved in the role of GB03 VOCs in regulating plant growth.
植物促生根际细菌（PGPR）是天然存在于土壤中的微生物，它们定殖在植物根部并刺激植物生长。一些 PGPR 菌株可以通过挥发性有机化合物（VOC）的排放，在与植物没有物理接触的情况下直接调节植物的生长。最近，我们描述了 通过对免疫系统和磷酸盐饥饿反应（PSR）系统的整体调节，对来自 菌株 GB03（GB03）的 VOC 二乙酰基做出不同的反应，从而导致共生或免疫。在缺磷条件下，二乙酰基增强了水杨酸和茉莉酸介导的免疫，从而导致植物对缺磷过度敏感。在这里，我们表明，外源性赤霉素（GA）的应用部分缓解了在缺磷条件下 无论是 GB03 VOC 还是二乙酰基引起的有害影响，而暴露于 GB03 VOC 的 DELLA 四重突变体则表现出对胁迫症状的部分减轻。此外，二乙酰基似乎增强了 DELLA 蛋白的积累，并增加了几个与 GA 失活相关的基因的表达。这些发现表明，DELLA 介导的 GA 信号通路参与了 GB03 VOC 调节植物生长的作用。
