Bacillus spp., a bio-control agent enhances the activity of antioxidant defense enzymes in rice against Pyricularia oryzae

Abstract

Plant growth promoting rhizobacteria (PGPR) are found to control the plant diseases by adopting various mechanisms. Induced systemic resistance (ISR) is an important defensive strategy manifested by plants against numerous pathogens especially infecting at aerial parts. Rhizobacteria elicit ISR by inducing different pathways in plants through production of various metabolites. In the present study, potential of Bacillus spp. KFP-5, KFP-7, KFP-17 was assessed to induce antioxidant enzymes against Pyricularia oryzae infection in rice. The antagonistic Bacillus spp. significantly induced antioxidant defense enzymes i-e superoxide dismutase (1.7–1.9-fold), peroxidase (3.5–4.1-fold), polyphenol oxidase (3.0–3.8-fold), phenylalanine ammonia-lyase (3.9–4.4-fold), in rice leaves and roots under hydroponic and soil conditions respectively. Furthermore, the antagonistic Bacillus spp significantly colonized the rice plants (2.0E+00–9.1E+08) and secreted multiple biocontrol determinants like protease (1.1–5.5 U/mg of soil or U/mL of hydroponic solution), glucanase, (1.0–1.3 U/mg of soil or U/mL of hydroponic solution), siderophores (6.5–42.8 μg/mL or mg) in the rhizosphere of different rice varieties. The results showed that treatment with Bacillus spp. enhanced the antioxidant defense activities in infected rice, thus alleviating P. oryzae induced oxidative damage and suppressing blast disease incidence.

Beneficial Endophytic Bacterial Populations Associated With Medicinal Plant Thymus vulgaris Alleviate Salt Stress and Confer Resistance to Fusarium oxysporum

“…In addition, the bacterial taxa observed were similar to endophytes observed using cultivation-independent techniques (Qin et al, 2012;Kaplan et al, 2013;Jin et al, 2014;Egamberdieva et al, 2017b). The dominant bacterial genus was Bacillus, which is known for its beneficial effects on plant growth and health (Radhakrishnan et al, 2017;Rais et al, 2017).…”

“…For example, Bacillus pumilus reduced the activity of caspase of salt-stressed rice plants (Jha and Subramanian, 2014). However, decreases in the activities of antioxidant enzymes could be due to a general decrease in biosynthesis and lower oxidative stress, as has been suggested by others (Egamberdieva et al, 2017b;Rais et al, 2017). In this study, the total chlorophyll in tomato leaves was slightly increased at different levels of salt concentrations when the plants were subjected to endophytes, but most of these effects were not statistically significant ( Figure 5D).…”

Induction of defense mechanisms involved in disease resistance of onion blight disease caused by Botrytis allii

“…Recently, the induction of plant resistance by the application of many microorganisms or organic materials has emerged as a new strategy in the management of plant diseases (Rais et al 2017). Plants are a storehouse of natural compounds that subscribe in suppressing phytopathogens (Sales et al 2016) of which plants supply a worthy source of active natural chemicals such as flavonoids, alkaloids, cucurbitacin, terpenoids, and glycosides (Koul and Walia 2009).…”

The impact of microbes in the orchestration of plants’ resistance to biotic stress: a disease management approach

“…The bacterium Bacillus sp. capable of inducing the production of antioxidant defense enzymes (superoxide dismutase, peroxidase, polyphenol oxidase, phenylalanine ammonia lyase) in rice plant strengthened its resistance to Pyricularia oryzae infection (Rais et al 2017 ).…”