Mal Sadananda, Panchal Shweta
School of Biosciences and Technology, Vellore Institute of Technology, Vellore, India.
Front Plant Sci. 2024 Jul 2;15:1422504. doi: 10.3389/fpls.2024.1422504. eCollection 2024.
Abiotic stresses, especially drought stress and salt stress in crop plants are accelerating due to climate change. The combined impact of drought and salt is anticipated to lead to the loss of up to 50% of arable land globally, resulting in diminished growth and substantial yield losses threatening food security. Addressing the challenges, agriculture through sustainable practices emerges as a potential solution to achieve Zero Hunger, one of the sustainable development goals set by the IUCN. Plants deploy a myriad of mechanisms to effectively address drought and salt stress with phytohormones playing pivotal roles as crucial signaling molecules for stress tolerance. The phytohormone auxin, particularly indole acetic acid (IAA) emerges as a paramount regulator integral to numerous aspects of plant growth and development. During both drought and salt stress conditions, auxin plays crucial roles for tolerance, but stress-induced processes lead to decreased levels of endogenous free auxin in the plant, leading to an urgent need for auxin production. With an aim to augment this auxin deficiency, several researchers have extensively investigated auxin production, particularly IAA by plant-associated microorganisms, including endophytic bacteria. These endophytic bacteria have been introduced into various crop plants subjected to drought or salt stress and potential isolates promoting plant growth have been identified. However, post-identification, essential studies on translational research to advance these potential isolates from the laboratory to the field are lacking. This review aims to offer an overview of stress tolerant auxin-producing endophytic bacterial isolates while identifying research gaps that need to be fulfilled to utilize this knowledge for the formulation of crop-specific and stress-specific endophyte bioinoculants for the plant to cope with auxin imbalance occurring during these stress conditions.
由于气候变化，农作物面临的非生物胁迫，尤其是干旱胁迫和盐胁迫正在加剧。预计干旱和盐害的综合影响将导致全球多达50%的耕地流失，从而使作物生长减缓，产量大幅下降，威胁粮食安全。为应对这些挑战，通过可持续农业实践成为实现零饥饿的一个潜在解决方案，零饥饿是世界自然保护联盟设定的可持续发展目标之一。植物通过多种机制有效应对干旱和盐胁迫，其中植物激素作为胁迫耐受性的关键信号分子发挥着核心作用。植物激素生长素，尤其是吲哚乙酸（IAA），是植物生长和发育诸多方面不可或缺的首要调节因子。在干旱和盐胁迫条件下，生长素都对耐受性起着关键作用，但胁迫诱导的过程会导致植物体内内源性游离生长素水平降低，因此迫切需要生长素的产生。为了弥补这种生长素缺乏，一些研究人员广泛研究了植物相关微生物，包括内生细菌产生生长素，特别是IAA的情况。这些内生细菌已被引入遭受干旱或盐胁迫的各种作物中，并已鉴定出促进植物生长的潜在菌株。然而，在鉴定之后，缺乏将这些潜在菌株从实验室推进到田间的转化研究的关键研究。本综述旨在概述产生生长素的耐胁迫内生细菌菌株，同时确定为利用这些知识为作物配制特定作物和特定胁迫的内生菌生物菌剂以应对这些胁迫条件下发生的生长素失衡所需填补的研究空白。
