Othibeng Kgalaletso, Nephali Lerato, Myoli Akhona, Buthelezi Nombuso, Jonker Willem, Huyser Johan, Tugizimana Fidele
Department of Biochemistry, University of Johannesburg, Auckland Park, Johannesburg 2006, South Africa.
International Research and Development Division, Omnia Group, Johannesburg 2021, South Africa.
Plants (Basel). 2022 Feb 14;11(4):510. doi: 10.3390/plants11040510.
The use of microbial biostimulants in the agricultural sector is increasingly gaining momentum and drawing scientific attention to decode the molecular interactions between the biostimulants and plants. Although these biostimulants have been shown to improve plant health and development, the underlying molecular phenomenology remains enigmatic. Thus, this study is a metabolomics work to unravel metabolic circuits in sap extracts from maize plants treated with a microbial biostimulant, under normal and drought conditions. The biostimulant, which was a consortium of different strains, was applied at the planting stage, followed by drought stress application. The maize sap extracts were collected at 5 weeks after emergence, and the extracted metabolites were analyzed on liquid chromatography-mass spectrometry platforms. The acquired data were mined using chemometrics and bioinformatics tools. The results showed that under both well-watered and drought stress conditions, the application of the biostimulant led to differential changes in the profiles of amino acids, hormones, TCA intermediates, phenolics, steviol glycosides and oxylipins. These metabolic changes spanned several biological pathways and involved a high correlation of the biochemical as well as structural metabolic relationships that coordinate the maize metabolism. The hypothetical model, postulated from this study, describes metabolic events induced by the microbial biostimulant for growth promotion and enhanced defences. Such understanding of biostimulant-induced changes in maize sap pinpoints to the biochemistry and molecular mechanisms that govern the biostimulant-plant interactions, which contribute to ongoing efforts to generate actionable knowledge of the molecular and physiological mechanisms that define modes of action of biostimulants.
微生物生物刺激素在农业领域的应用正日益兴起，并吸引了科学界的关注，以解码生物刺激素与植物之间的分子相互作用。尽管这些生物刺激素已被证明能改善植物健康和生长发育，但其潜在的分子现象学仍然神秘莫测。因此，本研究是一项代谢组学工作，旨在揭示在正常和干旱条件下，用微生物生物刺激素处理的玉米植株汁液提取物中的代谢途径。这种生物刺激素是由不同菌株组成的联合体，在种植阶段施用，随后施加干旱胁迫。在玉米出苗后5周收集其汁液提取物，并在液相色谱 - 质谱平台上分析提取的代谢物。使用化学计量学和生物信息学工具对获得的数据进行挖掘。结果表明，在充分浇水和干旱胁迫条件下，生物刺激素的施用均导致氨基酸、激素、三羧酸循环中间体、酚类、甜菊糖苷和氧脂素的谱图发生差异变化。这些代谢变化跨越了多个生物途径，涉及协调玉米代谢的生化以及结构代谢关系的高度相关性。本研究提出的假设模型描述了微生物生物刺激素诱导的促进生长和增强防御的代谢事件。对生物刺激素诱导的玉米汁液变化的这种理解，明确了控制生物刺激素 - 植物相互作用的生物化学和分子机制，这有助于为生成关于生物刺激素作用模式的分子和生理机制的可操作知识而持续努力。
