Influence of Plant Growth-Promoting Rhizobacteria on the Formation of Apoplastic Barriers and Uptake of Water and Potassium by Wheat Plants

Abstract

The formation of apoplastic barriers is important for controlling the uptake of water and ions by plants, thereby influencing plant growth. However, the effects of plant growth-promoting bacteria on the formation of apoplastic barriers, and the relationship between these effects and the ability of bacteria to influence the content of hormones in plants, have not been sufficiently studied. The content of cytokinins, auxins and potassium, characteristics of water relations, deposition of lignin and suberin and the formation of Casparian bands in the root endodermis of durum wheat (Triticum durum Desf.) plants were evaluated after the introduction of the cytokinin-producing bacterium Bacillus subtilis IB-22 or the auxin-producing bacterium Pseudomonas mandelii IB-Ki14 into their rhizosphere. The experiments were carried out in laboratory conditions in pots with agrochernozem at an optimal level of illumination and watering. Both strains increased shoot biomass, leaf area and chlorophyll content in leaves. Bacteria enhanced the formation of apoplastic barriers, which were most pronounced when plants were treated with P. mandelii IB-Ki14. At the same time, P. mandelii IB-Ki14 caused no decrease in the hydraulic conductivity, while inoculation with B. subtilis IB-22, increased hydraulic conductivity. Cell wall lignification reduced the potassium content in the roots, but did not affect its content in the shoots of plants inoculated with P. mandelii IB-Ki14. Inoculation with B. subtilis IB-22 did not change the potassium content in the roots, but increased it in the shoots.

Effect of ipt Gene Induction in Transgenic Tobacco Plants on Hydraulic Conductance, Formation of Apoplastic Barriers and Aquaporin Activity under Heat Shock

“…Lignin and suberin were identified as described in [ 39 ]. Basal pieces of lateral root were fixed in a mixture (7:7:100) of formalin, acetic acid, and ethanol 70%, dehydrated in an ethanol series, cleared with xylene, and embedded in paraffin.…”

Phytohormone-Producing Rhizobacteria and Their Role in Plant Growth

“…and Bacillus pumilus enhanced growth of sunflower (Helianthus annuusL.) [54] Pseudomonas fluorescens enhanced root growth, nutrient uptake, and overall wheat growth [55] Bacillus subtilis promoted a rapid recovery of the growth rates of shoots, as well as the wet and dry mass of roots potato (Solarium tuberosum L.) [56] Azospirillum brasilense treatment in maize plants enhanced plant growth, nitrogen fixation, and improved drought resistance [28] Azotobacter chroococcum induced stomatal closure, improved water-use efficiency, and enhanced plant growth in maize plants [57] Phytohormone-Producing Rhizobacteria and Their Role in Plant Growth DOI: http://dx.doi.org/10.5772/intechopen.1002823…”

“…Cytokinins are known to stimulate cell division and growth in plants. Rhizobacteria that produce cytokinins can enhance this process in plant roots, leading to increased root mass and overall plant growth [55]. Cytokinins produced by rhizobacteria can improve nutrient uptake in plants, particularly essential minerals like nitrogen, phosphorus, and potassium [56,57].…”

Biopotential of rhizobacteria to improve growth and phytochemical content in Javanese ginseng (Talinum paniculatum) herbal plant

“…The colonization of rooted rhizobacteria is intricately linked to the rhizobacteria's capacity to synthesize hormones and enzymes (Sagar et al, 2020). The strain P. mandelii IB-Ki14, which can synthesize indole-3-acetic acid (IAA) under laboratory conditions, significantly elevated the levels of auxins in the roots by almost 100% and in the shoots by approximately 50% as compared to the control group in wheat plants (Akhtyamova et al, 2023). As per Hassan et al (2019), certain rhizobacteria that live in plant roots can also invade the interior of the roots and proliferate.…”