Yang Xue, Xie Yongli, Qiao Youming, Chang Feifei, Wang Tian, Li Junxi, Wu Lingling, Li Chen, Gao Ying
College of Agriculture and Animal Husbandry, Qinghai University, Xining, China.
Key Laboratory of Use of Forage Germplasm Resources on Tibetan Plateau of Qinghai Province, Qinghai University, Xining, China.
Front Plant Sci. 2024 May 13;15:1378707. doi: 10.3389/fpls.2024.1378707. eCollection 2024.
This study used DGL1 isolated from the arid sandy land of the Qinghai-Tibetan Plateau as the research strain and investigated the effects of DGL1 on the biomass, physiology, and metabolites of under different intensities of drought stress to provide a high-quality bacterial source and a theoretical basis for the research and development of biological fertilizer suitable for arid areas.
The exopolysaccharides (EPS), 1-Aminocyclopropane-1-carboxylate deaminase (ACC), and phosphorus solubilizing capacity of DGL1 were determined. The effects of a DGL1 suspension on alfalfa biomass, physiological indexes, degree of peroxidation of cell membranes, and activity of antioxidant enzymes were determined after irrigating roots under drought stress. The effects on soil physicochemical properties were also evaluated, and metabolomics analysis was performed to explore the effect of DGL1 on the metabolites of alfalfa under drought stress.
Strain DGL1 produced extracellular polysaccharide EPS and ACC deaminase and was capable of phosphorus solubilization. Treatment with DGL1 increased the biomass of alfalfa under different degrees of drought stress, significantly increased the activities of alfalfa antioxidant enzymes (SOD), Peroxidase (POD), and catalase (CAT), reduced the content of MDA and HO, and increased the content of quick-acting phosphorus, quick-acting potassium, ammonium nitrogen, and nitrate nitrogen in the soil, thus improving soil fertility. Through metabolomics analysis, DGL1 was shown to affect amino acid metabolic pathways, such as arginine, leucine, glutamate, and tyrosine, as well as the levels of energy-providing polysaccharides and lipids, in alfalfa under 15% PEG-6000 drought stress, enhancing alfalfa's capacity to resist drought stress.
Strain DGL1 enhances the drought suitability of alfalfa and has the potential for dryland development as a biological agent.
本研究以从青藏高原干旱沙地分离得到的DGL1作为研究菌株，探究了不同强度干旱胁迫下DGL1对紫花苜蓿生物量、生理特性及代谢产物的影响，旨在为干旱地区生物肥料的研发提供优质菌种资源及理论依据。
测定了DGL1的胞外多糖（EPS）、1-氨基环丙烷-1-羧酸脱氨酶（ACC）及解磷能力。在干旱胁迫下对紫花苜蓿根部进行浇灌后，测定了DGL1菌悬液对紫花苜蓿生物量、生理指标、细胞膜过氧化程度及抗氧化酶活性的影响。同时评估了其对土壤理化性质的影响，并进行代谢组学分析以探究干旱胁迫下DGL1对紫花苜蓿代谢产物的影响。
菌株DGL1能产生胞外多糖EPS和ACC脱氨酶，且具有解磷能力。DGL1处理提高了不同程度干旱胁迫下紫花苜蓿的生物量，显著提高了紫花苜蓿抗氧化酶超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）的活性，降低了丙二醛（MDA）和过氧化氢（H₂O₂）的含量，增加了土壤中速效磷、速效钾、铵态氮和硝态氮的含量，从而提高了土壤肥力。通过代谢组学分析表明，在15% PEG-6000干旱胁迫下，DGL1影响了紫花苜蓿中精氨酸、亮氨酸、谷氨酸和酪氨酸等氨基酸代谢途径以及提供能量的多糖和脂质水平，增强了紫花苜蓿抵御干旱胁迫的能力。
菌株DGL1增强了紫花苜蓿的干旱适应性，作为生物制剂具有旱地开发潜力。
