Agricultural manipulation of potentially beneficial rhizosphere microbes is increasing rapidly due to their multi-functional plant-protective and growth related benefits. Plant growth promoting rhizobacteria (PGPR) are mostly non-pathogenic microbes which exert direct benefits on plants while there are rhizosphere bacteria which indirectly help plant by ameliorating the biotic and/or abiotic stress or induction of defense response in plant. Regulation of these direct or indirect effect takes place via highly specialized communication system induced at multiple levels of interaction i.e., inter-species, intra-species, and inter-kingdom. Studies have provided insights into the functioning of signaling molecules involved in communication and induction of defense responses. Activation of host immune responses upon bacterial infection or rhizobacteria perception requires comprehensive and precise gene expression reprogramming and communication between hosts and microbes. Majority of studies have focused on signaling of host pattern recognition receptors (PRR) and nod-like receptor (NLR) and microbial effector proteins under mining the role of other components such as mitogen activated protein kinase (MAPK), microRNA, histone deacytylases. The later ones are important regulators of gene expression reprogramming in plant immune responses, pathogen virulence and communications in plant-microbe interactions. During the past decade, inoculation of PGPR has emerged as potential strategy to induce biotic and abiotic stress tolerance in plants; hence, it is imperative to expose the basis of these interactions. This review discusses microbes and plants derived signaling molecules for their communication, regulatory and signaling networks of PGPR and their different products that are involved in inducing resistance and tolerance in plants against environmental stresses and the effect of defense signaling on root microbiome. We expect that it will lead to the development and exploitation of beneficial microbes as source of crop biofertilizers in climate changing scenario enabling more sustainable agriculture.

由于其对植物的多功能保护作用和与生长有关的好处，对潜在有益的根际微生物的农业操作正在迅速增加。促进植物生长的根际细菌（PGPR）主要是对植物具有直接益处的非致病性微生物，而有的根际细菌可通过缓解生物和/或非生物胁迫或诱导植物防御反应间接帮助植物。这些直接或间接作用的调节是通过高度专业化的通信系统进行的，该通信系统在多个交互级别上产生，即，种间，种内和王国间。研究提供了对参与通信和防御反应诱导的信号分子功能的见解。感染细菌或根瘤菌后，宿主免疫反应的激活需要全面而精确的基因表达重编程以及宿主与微生物之间的通讯。大多数研究集中在宿主模式识别受体（PRR）和点头样受体（NLR）和微生物效应蛋白的信号传导上，其方法是挖掘其他成分的作用，例如有丝分裂原活化蛋白激酶（MAPK），microRNA，组蛋白脱酰基。后者是植物免疫反应，病原体毒力和植物-微生物相互作用中的基因表达重编程的重要调节剂。在过去的十年中，PGPR接种已成为诱导植物抗生物和非生物胁迫的潜在策略。因此，必须公开这些交互作用的基础。这篇综述讨论了微生物和植物衍生的信号分子，用于它们与PGPR的通讯，调控和信号网络以及它们的不同产品，这些产物参与诱导植物对环境胁迫的抗性和耐受性以及防御信号对根部微生物组的影响。我们预计，在气候变化的情况下，它将导致有益微生物的开发和利用，将其作为作物生物肥料的来源，从而实现更可持续的农业发展。这篇综述讨论了微生物和植物衍生的信号分子，用于它们与PGPR的通讯，调控和信号网络以及它们的不同产品，这些产物参与诱导植物对环境胁迫的抗性和耐受性以及防御信号对根部微生物组的影响。我们预计，在气候变化的情况下，它将导致有益微生物的开发和利用，将其作为作物生物肥料的来源，从而实现更可持续的农业发展。这篇综述讨论了微生物和植物衍生的信号分子，用于它们与PGPR的通讯，调控和信号网络以及它们的不同产品，这些产物参与诱导植物对环境胁迫的抗性和耐受性以及防御信号对根部微生物组的影响。我们预计，在气候变化的情况下，它将导致有益微生物的开发和利用，将其作为作物生物肥料的来源，从而实现更可持续的农业发展。