Plant Root Enhancement by Plant Growth Promoting Rhizobacteria

Abstract

Soil microorganisms perform a variety of functions, some of which are extremely helpful to the maintenance of ecological sustainability. Bacteria thriving in the plant rhizosphere drive plant development through a variety of ways, which are referred to as PGPR (plant growth-promoting rhizobacteria). Despite the fact that there are many different types of PGPR, their significance and applications in sustainable agriculture are still debated and limited. The performance of PGPR varies, which might be related to a variety of environmental conditions that impact their development and proliferation in plants. PGPR is a nonpathogenic, friendly bacterium that stimulates plant development by altering hormone concentrations and nutritional needs, as well as mitigating stress-related damage. PGPR colonizes root hairs and lateral roots in plants, where they may exhibit their beneficial characteristics. Rhizobacteria that promote plant development have the ability to control root system architecture (RSA), as well as the vegetative growth and physiology of the entire plant. The generation of hormones like Indole acetic acid (IAA) by PGPR has long been linked to RSA effects. This book chapter reviews to show PGPR affects on the growth, physiological, biochemical, and molecular characteristics of plant roots.

Potential of Phosphorus Solubilizing Purple Nonsulfur Bacteria Isolated from Acid Sulfate Soil in Improving Soil Property, Nutrient Uptake, and Yield of Pineapple (Ananas comosus L. Merrill) under Acidic Stress

“…Tis result matched with previous researches [2,24,26]. Moreover, biofertilizers containing rhizosphere bacteria can produce phytohormones, including acetic acid, auxins, and cytokinins, to support the plant development [46,47]. Tus, PNSB can be used as plant growth promoting bacteria to supply IAA, ALA for plant [14,24].…”

Plant growth promoting rhizobacteria (PGPR) and their role in plant-parasitic nematodes control: a fresh look at an old issue

“…These bacteria are known as PGPR (Kumar et al 2015). Plant growth promoting rhizobacteria are bacteria that live in the "rhizosphere" of a plant's roots and promote plant regulators and boost nutrient availability (PGPR) (Turan et al 2021). In the soil, diverse microorganisms such as Rhizobium sp., Xanthomonas, Bacillus sp., Arthrobacter sp., Bradyrhizobium sp., Frankia sp., Enterobacter sp., Proteus sp., Klebsiella sp., Flavobacterium sp., Pseudomonas sp., Serratia sp., Microbacterium sp., and Erwinia sp.…”

Plant-Bacterial Symbiosis: An Ecologically Sustainable Agriculture Production Alternative to Chemical Fertilizers

“…A group of natural soil bacterial flora that resides in the rhizosphere and grows in, on, or around plant roots [67] and has a beneficial effect on the plant's overall health is referred to as PGPR [68]. PGPR is a nonpathogenic, beneficial bacterium that promotes plant growth by modifying hormone levels and nutritional requirements, as well as reducing stress-related damage [69]. Nutrient absorption is thought to be increased as a result of the increased root surface area mediated by PGPR.…”

“…Cytokinin, either alone or in combination with other phytohormones like abscisic acid and auxin, can help salt-stressed plants grow faster while also improving resistance by altering the expression of genes [127]. PGPRs, such as Bradyrhizobiumjaponicum, Azospirillumbrasilense, Pseudomonas fluorescens, Arthrobactergiacomelloi, Paenibacilluspolymyxa, and Bacillus licheniformis, have been demonstrated to produce cytokinin (particularly zeatin) [69]. Cytokininproducing PGPRs act as biocontrol agents against a variety of pathogens [128].…”

“…Many biotic and abiotic stresses are causing havoc on the sector, resulting in enormous plant productivity losses all around the world. Stress factors comprise nutrient shortages, heavy metal contamination, high wind, extreme temperatures, salinity, drought, illnesses, plant invasions, pests, salt, and soil erosion [69].…”