Recent Advances in the Bacterial Phytohormone Modulation of Plant Growth

Abstract

Phytohormones are regulators of plant growth and development, which under different types of stress can play a fundamental role in a plant’s adaptation and survival. Some of these phytohormones such as cytokinin, gibberellin, salicylic acid, auxin, and ethylene are also produced by plant growth-promoting bacteria (PGPB). In addition, numerous volatile organic compounds are released by PGPB and, like bacterial phytohormones, modulate plant physiology and genetics. In the present work we review the basic functions of these bacterial phytohormones during their interaction with different plant species. Moreover, we discuss the most recent advances of the beneficial effects on plant growth of the phytohormones produced by PGPB. Finally, we review some aspects of the cross-link between phytohormone production and other plant growth promotion (PGP) mechanisms. This work highlights the most recent advances in the essential functions performed by bacterial phytohormones and their potential application in agricultural production.

Improving rice drought tolerance through host-mediated microbiome selection

“…Lipids have been identified as a key avenue of communication between hosts and microbes during plant microbe interactions, including beneficial symbioses (Siebers et al 2016). Additionally, on the list of significantly enriched secondary metabolite COGs are cytochrome P450s, which are capable of producing a wide array of many small molecules, including phytohormones and other compounds used by microbial partners to manipulate plant fitness (Orozco-Mosqueda, Santoyo, and Glick 2023).…”

“…Plant-associated microbiota directly affect the fitness of their hosts through a variety of mechanisms. These mechanisms include interactions with plant immunity (Pieterse et al 2014; Durrant and Dong 2004; Schlatter et al 2017), secretion and metabolism of phytohormones and other signaling molecules (Orozco-Mosqueda, Santoyo, and Glick 2023; Spaepen 2015; Spaepen and Vanderleyden 2011; Glick 2005), mediating nutrient bioavailability (P. Xu and Wang 2023; Richardson and Simpson 2011; Kramer, Özkaya, and Kümmerli 2020), and otherwise altering the physico-chemical environment experienced by plants (Liu et al 2020; Kumar et al 2020). Intentional manipulation of plant microbiomes to enhance fitness—through growth promotion, disease suppression, and alleviation of abiotic stress—therefore represents an alternative or supplement to plant breeding to improve agricultural productivity (Friesen et al 2011; Finkel et al 2017; Shayanthan, Ordoñez, and Oresnik 2022; Vorholt et al 2017).…”

Exploring the connectivity between rhizosphere microbiomes and the plant genes: A way forward for sustainable increase in primary productivity

“…It also significantly boosted above-ground growth. In addition, the rhizosphere microbiome can control plant growth-related gene expression by relocating nutrients, changing the efficiency of how plants utilize nutrients, and generating hormones including volatile chemicals and IAA (Orozco-Mosqueda et al, 2023).…”

Intermittent water stress favors microbial generalists that better help wheat under drought

“…The microbial 1-aminocyclopropane-1-carboxylate (ACC) deaminase degrades the precursor of the stress hormone ethylene [8]. Furthermore, the production of auxins and cytokinins by microorganisms can promote plant growth and resistance to stress [9, 10].…”