Lucas Jose Antonio, Garcia-Villaraco Ana, Montero-Palmero Maria Belen, Montalban Blanca, Ramos Solano Beatriz, Gutierrez-Mañero Francisco Javier
Plant Physiology, Pharmaceutical and Health Sciences Department, Faculty of Pharmacy, Universidad San Pablo-CEU, CEU-Universities, 28668 Boadilla del Monte, Spain.
Biology (Basel). 2023 Jun 23;12(7):901. doi: 10.3390/biology12070901.
Physiological, metabolic, and genetic changes produced by two plant growth promoting rhizobacteria (PGPR) sp. (internal code of the laboratory: N 5.12 and N 21.24) inoculated in tomato plants subjected to moderate water stress (10% polyethylene glycol-6000; PEG) were studied. Photosynthesis efficiency, photosynthetic pigments, compatible osmolytes, reactive oxygen species (ROS) scavenging enzymes activities, oxidative stress level and expression of genes related to abscisic acid synthesis (ABA; 9-cis-epoxycarotenoid dioxygenase gene), proline synthesis (Pyrroline-5-carboxylate synthase gene), and plasma membrane ATPase ( gene) were measured. Photosynthetic efficiency was compromised by PEG, but bacterial-inoculated plants reversed the effects: while N5.12 increased carbon fixation (37.5%) maintaining transpiration, N21.24 increased both (14.2% and 31%), negatively affecting stomatal closure, despite the enhanced expression of NCDE1 and plasma membrane ATPase genes, evidencing the activation of different adaptive mechanisms. Among all parameters evaluated, photosynthetic pigments and antioxidant enzymes guaiacol peroxidase (GPX) and ascorbate peroxidase (APX) responded differently to both strains. N 5.12 increased photosynthetic pigments (70% chlorophyll a, 69% chlorophyll b, and 65% carotenoids), proline (33%), glycine betaine (4.3%), and phenolic compounds (21.5%) to a greater extent, thereby decreasing oxidative stress (12.5% in Malondialdehyde, MDA). Both bacteria have highly beneficial effects on tomato plants subjected to moderate water stress, improving their physiological state. The use of these bacteria in agricultural production systems could reduce the amount of water for agricultural irrigation without having a negative impact on food production.
研究了两种植物促生根际细菌（PGPR）菌株（实验室内部编号：N 5.12和N 21.24）接种到遭受中度水分胁迫（10%聚乙二醇-6000；PEG）的番茄植株后所产生的生理、代谢和遗传变化。测量了光合作用效率、光合色素、相容性渗透剂、活性氧（ROS）清除酶活性、氧化应激水平以及与脱落酸合成相关的基因（ABA；9-顺式环氧类胡萝卜素双加氧酶基因）、脯氨酸合成相关的基因（吡咯啉-5-羧酸合成酶基因）和质膜ATP酶（基因）的表达。PEG降低了光合作用效率，但接种细菌的植株逆转了这种影响：N5.12增加了碳固定（37.5%）并维持蒸腾作用，N21.24同时增加了碳固定（14.2%）和蒸腾作用（31%），尽管NCDE1和质膜ATP酶基因表达增强，但对气孔关闭产生了负面影响，这证明了不同适应机制的激活。在所有评估参数中，光合色素以及抗氧化酶愈创木酚过氧化物酶（GPX）和抗坏血酸过氧化物酶（APX）对两种菌株的反应不同。N 5.12在更大程度上增加了光合色素（叶绿素a增加70%、叶绿素b增加69%、类胡萝卜素增加65%）、脯氨酸（33%）、甘氨酸甜菜碱（4.3%）和酚类化合物（21.5%），从而降低了氧化应激（丙二醛，MDA降低12.5%）。这两种细菌对遭受中度水分胁迫的番茄植株都有非常有益的影响，改善了它们的生理状态。在农业生产系统中使用这些细菌可以减少农业灌溉用水量，而不会对粮食生产产生负面影响。
