Bacillus atrophaeus HAB-5 secretion metabolites preventing occurrence of systemic diseases in tobacco plant

Abstract

Finding synthetic pesticide alternatives for health and a healthy environment has become a crucial issue for scientific research. A number of studies have reported efficacy of Bacillus species on promoting plant development, as well as protecting plants against pathogen invasion, especially pathogenic fungi and bacteria. However, little was known about Bacillus species in controlling viral diseases. In this study, Bacillus atrophaeus strain HAB-5, isolated from cotton field, Xinjiang, China efficiently promoted the growth of tobacco plants. According to the results, the treatment with the strain HAB-5 increased the expression of NtEXP1 and NtEXP2. Then the Tobacco mosaic virus (TMV)/ Nicotiana tobacco system was employed to evaluate virus resistance induced by strain HAB-5. Tobacco leaves were treated with antimicrobial metabolites of strain HAB-5 (1 mg/mL), and 12 h later the treated leaves were challenged with TMV via rub-inoculation. The results showed that disease symptoms were obviously compromised by tobacco leaves treated with strain HAB-5, and the viral accumulation level was reduced extensively. Moreover, it was found that the signaling regulatory gene (NPR1), defense genes (PR-1a, PR-1b, Chia5), and hypertensive response related genes (Hsr203J, Hin1) were up-regulated in plants treated with the metabolites. Altogether, these accumulated results strongly support strain HAB-5 to be a biological controlling agent against TMV.

An Optimized in situ Quantification Method of Leaf H2O2 Unveils Interaction Dynamics of Pathogenic and Beneficial Bacteria in Wheat

“…For example, endophytic bacteria-primed Abelmoschus esculentus plants expressed lower level of H 2 O 2 accumulation upon Sclerotium rolfsii challenge, compared to unprimed plants, probably due to the enhanced expression of antioxidant enzymes ( Ray et al, 2016 ). In tobacco leaves, Bacillus atrophaeus HAB-5 inhibited ROS accumulation in leaves during TMV infection, which was related with enhanced resistance against the virus and inhibition of cell death ( Rajaofera et al, 2020 ). Besides, the fungus T. harzianum –mediated biocontrol may be related to alleviating Rhizoctonia solani -induced oxidative stress by reducing the levels of hydroxyl radical, O 2 ⋅– and H 2 O 2 after pathogen challenge ( Singh and Singh, 2011 ).…”

Comparative genomic analysis of Bacillus atrophaeus HAB-5 reveals genes associated with antimicrobial and plant growth-promoting activities

“…The gene ontology (GO) analysis (D) groups the genes into three categories: biological processes, cellular components, and molecular functions. Dahar et al 10.3389/fmicb.2024.1384691 Frontiers in Microbiology 06 frontiersin.org plant growth and antimicrobial activity (Rajaofera et al, 2018(Rajaofera et al, , 2019(Rajaofera et al, , 2020. AntiSMASH predicted a total of 11 gene clusters in the HAB-5 genome (Blin et al, 2013).…”

“…The HAB-5 strain has potential as a biological agent for antifungal and antiviral agents. Previous studies conducted in our laboratory have shown that HAB-5 can provide high control efficacy against 22 plant pathogenic fungi such as Alternaria alternata MfAa-1, Alternaria brassicicola MfAb- (Rajaofera et al, 2020). It also prevents disease infection, protects tobacco seedlings from P. nicotianae, and exhibits an antiviral effect against tobacco mosaic virus (TMV) by activating the signaling of regulatory genes (NPR1), defense genes (PR-1a, PR-1b, and chia5), and hypertensive response-related genes (Hsr 203j and Hin1; Rajaofera et al, 2019).…”

“…Previous studies conducted in our laboratory have shown that HAB-5 can provide high control efficacy against 22 plant pathogenic fungi such as Alternaria alternata MfAa-1, Alternaria brassicicola MfAb-1, Colletotrichum gloeosporioides MnCg-2, Colletotrichum musae BnCy-1, Colletotrichum gloeosporioides MnCg-3, Colletotrichum gloeosporioides MnCg-4, Colletotrichum gloeosporioides MnCg-1, Colletotrichum gloeosporioides MnCg-5, Colletotrichum gloeosporioides MnCg-6, Colletotrichum gloeosporioides MnCg-7, Colletotrichum gloeosporioides MnCg-9, Colletotrichum gloeosporioides MnCg-10, Colletotrichum gloeosporioides MnCg-11, Corynespora cassiicola HbCc-1, Corynespora cassiicola HbCc-2, Curvularia geniculata CyCg-1, Fusarium oxysporum f. sp. cubense FOC-4, Fusarium proliferatum PgFp-1, Fusarium oxysporum PgFp-2, Phyllosticta theaefolia , Phytophtora nicotianae, and Trichothecium roseum PyTr-1, and the inhibition range from 21.07 to 67.29% was recorded ( Rajaofera et al, 2020 ). It also prevents disease infection, protects tobacco seedlings from P. nicotianae , and exhibits an antiviral effect against tobacco mosaic virus (TMV) by activating the signaling of regulatory genes (NPR1), defense genes (PR-1a, PR-1b, and chia5), and hypertensive response-related genes (Hsr 203j and Hin1; Rajaofera et al, 2019 ).…”

An Endophytic Strain of Bacillus amyloliquefaciens Suppresses Fusarium oxysporum Infection of Chinese Wolfberry by Altering Its Rhizosphere Bacterial Community

“…PGPR colonize the root surface and the closely adhering soil interface (i.e., the rhizosphere) and some of them can also enter the root interior as endophytes ( Compant et al, 2005 ; Beneduzi et al, 2012 ; Lyu et al, 2019 ). PGPR enhance nutrient availability, stimulate growth hormones, and suppress disease prevalence ( Passari et al, 2018 ; Lyu et al, 2019 ; Rajaofera et al, 2020 ). Moreover, PGPR can suppress a broad range of pathogenic microbes including viruses, bacteria and fungi ( Mazhar et al, 2016 ).…”