Seed priming with endophytic Bacillus subtilis strain-specifically improves growth of Phaseolus vulgaris plants under normal and salinity conditions and exerts anti-stress effect through induced lignin deposition in roots and decreased oxidative and osmotic damages

Self Cite

114

In agriculture, abiotic stress is one of the critical issues impacting the crop productivity and yield. Such stress factors lead to the generation of reactive oxygen species, membrane damage, and other plant metabolic activities. To neutralize the harmful effects of abiotic stress, several strategies have been employed that include the utilization of nanomaterials. Nanomaterials are now gaining attention worldwide to protect plant growth against abiotic stresses such as drought, salinity, heavy metals, extreme temperatures, flooding, etc. However, their behavior is significantly impacted by the dose in which they are being used in agriculture. Furthermore, the action of nanomaterials in plants under various stresses still require understanding. Hence, with this background, the present review envisages to highlight beneficial role of nanomaterials in plants, their mode of action, and their mechanism in overcoming various abiotic stresses. It also emphasizes upon antioxidant activities of different nanomaterials and their dose-dependent variability in plants’ growth under stress. Nevertheless, limitations of using nanomaterials in agriculture are also presented in this review.

Section: Priming With Nanoparticles: An Emerging Stress Elicitormentioning

confidence: 99%

Metal/Metalloid-Based Nanomaterials for Plant Abiotic Stress Tolerance: An Overview of the Mechanisms

Sarraf

Vishwakarma

Kumar³

et al. 2022

Self Cite

114

“…Endophytic B. subtilis strains may be more effective at protecting plant growth under long-term stress conditions because the conditions inside the plant (stable pH, humidity, nutrient flux, and a lack of competition from many microorganisms) offer a stable host environment, allowing the bacteria to thrive and manifest their positive effects [ 28 , 29 ]. However, the behavior of any bacterial strain is at least partially dependent on the host species or varietal characteristics, geographic origin, environment, and stress type/level during growth [ 30 , 31 , 32 , 33 , 34 , 35 ]. It is crucial to understand the mechanisms that underlie the interactions between host plants and endophytic B. subtilis under drought.…”

Section: Introductionmentioning

confidence: 99%

Role of Endogenous Salicylic Acid as a Hormonal Intermediate in the Bacterial Endophyte Bacillus subtilis-Induced Protection of Wheat Genotypes Contrasting in Drought Susceptibility under Dehydration

Lastochkina

Ivanov

Петрова

et al. 2022

Self Cite

Endophytic Bacillus subtilis is a non-pathogenic beneficial bacterium which promotes plant growth and tolerance to abiotic stresses, including drought. However, the underlying physiological mechanisms are not well understood. In this study, the potential role that endogenous salicylic acid (SA) plays in regulating endophytic B. subtilis-mediated drought tolerance in wheat (Triticum aestivum L.) was examined. The study was conducted on genotypes with contrasting levels of intrinsic drought tolerance (drought-tolerant (DT) cv. Ekada70; drought-susceptible (DS) cv. Salavat Yulaev). It was revealed that B. subtilis 10-4 promoted endogenous SA accumulation and increased the relative level of transcripts of the PR-1 gene, a marker of the SA-dependent defense pathway, but two wheat cultivars responded differently, with the highest levels exhibited in DT wheat seedlings. These had a positive correlation with the ability of strain 10-4 to effectively protect DT wheat seedlings against drought injury by decreasing osmotic and oxidative damages (i.e., proline, water holding capacity (WHC), and malondialdehyde (MDA)). However, the use of the SA biosynthesis inhibitor 1-aminobenzotriazole prevented endogenous SA accumulation under normal conditions and the maintenance of its increased level under stress as well as abolished the effects of B. subtilis treatment. Particularly, the suppression of strain 10-4-induced effects on proline and WHC, which are both contributing factors to dehydration tolerance, was found. Moreover, the prevention of strain 10-4-induced wheat tolerance to the adverse impacts of drought, as judged by the degree of membrane lipid peroxidation (MDA) and plant growth (length, biomass), was revealed. Thus, these data provide an argument in favor of a key role of endogenous SA as a hormone intermediate in triggering the defense responses by B. subtilis 10-4, which also afford the foundation for the development of the bacterial-induced tolerance of these two different wheat genotypes under dehydration.

“…This can help to strengthen the cell walls and subsequently ensure effective neutralization of the excess (damaging) stress-induced ROS increase, as well as prevent disruption of the integrity of cells' membrane structures and changes in their permeability under stress conditions. In favor of this, in our previous study, we demonstrated B. subtilis 10-4 intensified lignin deposition in roots of bean plants under normal conditions and exerted a protective effect under salinity decreasing oxidative damages [21]. Perhaps B. subtilis is perceived by plants as an agent that causes initial intracellular changes in the antioxidant system which, however, do not lead to seedling damage (Figure 1).…”

Section: Discussionmentioning

confidence: 80%

Contribution of Ascorbate and Glutathione in Endobacteria Bacillus subtilis-Mediated Drought Tolerance in Two Triticum aestivum L. Genotypes Contrasting in Drought Sensitivity

Maslennikova

Lastochkina

2021

Self Cite

We evaluated the effect of endobacteria Bacillus subtilis (strain 10–4) as a co-inoculant for promoting plant growth and redox metabolism in two contrasting genotypes of Triticum aestivum L. (wheat): Ekada70 (drought tolerant (DT)) and Salavat Yulaev (drought susceptible (DS)) in early stages of adaptation to drought (12% PEG–6000). Results revealed that drought reduced growth and dramatically augmented oxidative stress markers, i.e., hydrogen peroxide (H2O2) and lipid peroxidation (MDA). Furthermore, the depletion of ascorbate (AsA) and glutathione (GSH), accompanied by a significant activation of ascorbate peroxidase (APX) and glutathione reductase (GR), in both stressed wheat cultivars (which was more pronounced in DS genotype) was found. B. subtilis had a protective effect on growth and antioxidant status, wherein the stabilization of AsA and GSH levels was revealed. This was accompanied by a decrease of drought-caused APX and GR activation in DS plants, while in DT plants additional antioxidant accumulation and GR activation were observed. H2O2 and MDA were considerably reduced in both drought-stressed wheat genotypes because of the application of B. subtilis. Thus, the findings suggest the key roles in B. subtilis-mediated drought tolerance in DS cv. Salavat Yulaev and DT cv. Ekada70 played are AsA and GSH, respectively; which, in both cases, resulted in reduced cell oxidative damage and improved growth in seedlings under drought.