Among different abiotic stresses, drought stress is the leading cause of impaired plant growth and low productivity worldwide. It is therefore essential to understand the process of drought tolerance in plants and thus to enhance drought resistance. Accumulating evidence indicates that phytohormones are essential signalling molecules that regulate diverse processes of plant growth and development under drought stress. Plants can often respond to drought stress through a cascade of phytohormones signaling as a means of plant growth regulation. Understanding biosynthesis pathways and regulatory crosstalk involved in these vital compounds could pave the way for improving plant drought tolerance while maintaining overall plant health. In recent years, the identification of phytohormones related key regulatory genes and their manipulation through state-of-the-art genome engineering tools have helped to improve drought tolerance plants. To date, several genes linked to phytohormones signaling networks, biosynthesis, and metabolism have been described as a promising contender for engineering drought tolerance. Recent advances in functional genomics have shown that enhanced expression of positive regulators involved in hormone biosynthesis could better equip plants against drought stress. Similarly, knocking down negative regulators of phytohormone biosynthesis can also be very effective to negate the negative effects of drought on plants. This review explained how manipulating positive and negative regulators of phytohormone signaling could be improvised to develop future crop varieties exhibiting higher drought tolerance. Additionally, we also discuss the role of a promising genome editing tool, CRISPR/Cas9, on phytohormone mediated plant growth regulation for tackling drought stress.

中文翻译：

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植物激素正负调节因子之间的操纵相互作用：提高植物耐旱性的一种方法

在不同的非生物胁迫中，干旱胁迫是全球植物生长受损和生产力低下的主要原因。因此，了解植物耐旱的过程，从而增强抗旱性是必不可少的。越来越多的证据表明，植物激素是必不可少的信号分子，可在干旱胁迫下调节植物生长和发育的各种过程。植物通常可以通过作为植物生长调节手段的一系列植物激素信号来应对干旱胁迫。了解这些重要化合物中涉及的生物合成途径和监管串扰可以为提高植物耐旱性同时保持整体植物健康铺平道路。最近几年，与植物激素相关的关键调控基因的鉴定及其通过最先进的基因组工程工具进行操作有助于提高植物的耐旱性。迄今为止，与植物激素信号网络、生物合成和代谢相关的几个基因已被描述为工程耐旱性的有希望的竞争者。功能基因组学的最新进展表明，参与激素生物合成的正调节因子的增强表达可以更好地使植物抵御干旱胁迫。同样，击倒植物激素生物合成的负调节因子也可以非常有效地消除干旱对植物的负面影响。这篇综述解释了如何操纵植物激素信号的正负调节因子来开发未来具有更高耐旱性的作物品种。此外，我们还讨论了一种很有前途的基因组编辑工具 CRISPR/Cas9 在植物激素介导的植物生长调节以应对干旱胁迫方面的作用。