Unlocking PGPR-Mediated Abiotic Stress Tolerance: What Lies Beneath

Abstract

In the forthcoming era of climate change and ecosystem degradation, fostering the use of beneficial microbiota in agroecosystems represents a major challenge toward sustainability. Some plant-associated bacteria, called Plant Growth Promoting Rhizobacteria (PGPR), may confer growth-promoting advantages to the plant host, through enhancing nutrient uptake, altering hormone homeostasis, and/or improving tolerance to abiotic stress factors and phytopathogens. In this regard, exploring the key ecological and evolutionary interactions between plants and their microbiomes is perquisite to develop innovative approaches and novel natural products that will complement conventional farming techniques. Recently, details of the molecular aspects of PGPR-mediated tolerance to various stress factors have come to light. At the same time the integration of the recent advances in the field of plant-microbiome crosstalk with novel -omic approaches will soon allow us to develop a holistic approach to “prime” plants against unfavorable environments. This mini review highlights the current state of the art on seed biopriming, focusing on the identification and application of novel PGPR in cultivated plant species under conditions where crop productivity is limited. The potential challenges of commercializing these PGPR as biostimulants to improve crop production under multiple environmental constraints of plant growth, as well as concerns about PGPR application and their impact on ecosystems, are also discussed.

Interactive effects on ACC deaminase activity in salt‐tolerant plant growth‐promoting rhizobacteria and impacts on rice crop improvement

“…Application of plant growth‐promoting rhizobacteria (PGPRs) into the soil needs certain requirements that fulfil appropriate carriers, shelf‐life and sustainability of the rhizobacteria in the field. The key challenges for the universal application of the PGPR include storage incompatibility, short shelf‐life, inconsistent field performance and delicate application techniques required in field conditions (Mellidou & Karamanoli, 2022). The capability of the organism for efficient root colonization and generating positive response in host plant depends on plant–microbe interactions and soil factors (Hussain et al., 2022).…”

Halotolerant Pseudomonas koreensisS4T10 mitigate salt and drought stress in Arabidopsis thaliana

“…enhanced resistance to pathogens in Arabidopsis , whereas Kang et al (2022) demonstrated that PGPB aids in improving plant growth and nitrogen use efficiency. PGPB helps plants combat salt stress by regulating antioxidants, ion balance, and stress pathways like HKT and SOS and inducing ABA and indole acetic acid (IAA) to protect against drought stress (Mellidou and Karamanoli, 2022). In this study, we employed biochemical and genomic approaches to evaluate the potential of Pseudomonas koreensis strain S4T10 for enhancing the growth of Arabidopsis seedlings exposed to extended drought and salt stress.…”

“…Current research on crop rhizospheres reveals the frequent presence of Pseudomonas species that serve as potential PGPB (Ofek et al, 2014, Walters et al, 2018, Chiniquy et al, 2021. van (Mellidou and Karamanoli, 2022). In this study, we employed biochemical and genomic approaches to evaluate the potential of Pseudomonas koreensis strain S4T10 for enhancing the growth of Arabidopsis seedlings exposed to extended drought and salt stress.…”

Temperature-induced modulation of stress-tolerant PGP genes bioprospected from Bacillus sp. IHBT-705 associated with saffron (Crocus sativus) rhizosphere: A natural -treasure trove of microbial biostimulants

“…This is primarily due to the mode of selection process wherein PGP traits of microbes are assessed at a laboratory scale under highly controlled conditions, while field conditions are markedly different (Vasseur-Coronado et al, 2021). In fields, multiple factors interact, hence the PGP potentials of microbes are often lost or masked leading to underperformance (Backer et al, 2018;Mellidou and Karamanoli, 2022). Hence, the selection of the right microbe which does not lose its PGP traits under field conditions and various stresses is crucial (Amaya-Goḿez et al, 2020).…”