Burkholderia gladioli E39CS3, an endophyte of Crocus sativus Linn., induces host resistance against corm‐rot caused by Fusarium oxysporum

Abstract

Aim:To investigate the role of the leading saffron endophyte Burkholderia gladioli strain E39CS3 (BG-E39) in the inhibition of corm-rot and induced systemic resistance (ISR) in the host against the saffron specific pathogen, Fusarium oxysporum. Methods and Results: We studied the interaction between BG-E39 and the corm-rot pathogen F. oxysporum in vitro and in vivo. BG-E39 strongly inhibited both the F. oxysporum strains and other saffron-specific and non-specific pathogens used in this study. Confrontation and microscopic analyses revealed that the endophyte possessed fungicidal activity against the pathogens and effectively induced cell death in the mycelia. The endophyte produced chitinases as well as β-1,3-glucanase that may be involved in the pathogen cell wall degradation. BG-E39 did not cause corm-rot in Crocus sativus and the closely related plant, Gladiolus, thus establishing that it is non-pathogenic to these plants. The endophyte reduced corm-rot through antibiosis and enhanced the endogenous jasmonic acid (JA) levels and expression of JA-regulated and other plant defence genes. Conclusions:The bacterial endophyte BG-E39 provides resistance to the host plant against F. oxysporum corm-rot in nature. Significance and Impact of the Study: The current study discovers the role of the saffron endophyte BG-E39 in providing resistance to the host against corm-rot. Therefore, this endophyte is a potential candidate for developing a microbial formulation for the biocontrol of the most common disease of C. sativus.

Decoding the Plant Growth Promotion and Antagonistic Potential of Bacterial Endophytes From Ocimum sanctum Linn. Against Root Rot Pathogen Fusarium oxysporum in Pisum sativum

“…causing vascular wilt and root rot diseases are a major threat that hampers agricultural productivity resulting in enormous yield and economic losses in infected pea crops ( Porter et al, 2015 ; Bani et al, 2018 ). Endophytic biocontrol agents with multifarious PGPR characteristics have been successfully isolated from different plant parts such as Bacillus amyloliquefaciens FBZ24 ( Elanchezhiyan et al, 2018 ), Burkholderia gladioli E39CS3 ( Ahmad et al, 2021 ), Burkholderia cenocepacia 869T2 ( Ho et al, 2015 ), Enterobacter cloacae SM10 ( Tsuda et al, 2001 ) Bacillus tequilensis ( Bhattacharya et al, 2019 ), Bacillus subtilis ( Baysal et al, 2008 ), Bacillus velezensis B-36 ( Wang et al, 2020 ), Pseudomonas lini ( Muñoz Torres et al, 2021 ), and proactively used to ward-off the Fusarium wilt and root rot infection in different crops.…”

Rhizosphere microorganisms of Crocus sativus as antagonists against pathogenic Fusarium oxysporum

“…Enterobacter cloacae isolated from C. sativus could produce cellulase and indole acetic acid, which usually have the potential for disease resistance and growth promotion (Sharma et al, 2015). In addition, it has been found that B. gladioli E39CS3 isolated from C. sativus corms can significantly improve the disease resistance of C. sativus, and verified that B. gladioli can produce chitinase and b-1,3glucanase (Ahmad et al, 2022). In addition, because of the complexity of practical application, single biocontrol antagonists are usually considered to have the disadvantages of inadequate colonization and inefficient inhibition (Niu et al, 2020).…”

“…Among the genera with negative correlation, the bacterial genus Asanoa had the closest correlation (ρ = −0.7934, p < 0.001), whereas the closest fungal genus was Moniliophthora (ρ = −0.7047, p < 0.001). In addition, genera negatively correlated with RLA included many microbes of disease resistance, such as Massilia (ρ = −0.7277, p < 0.001) ( Li et al., 2021a ), Talaromyces (ρ = −0.6398, p < 0.001) ( Tian et al., 2021c ), Burkholderia (ρ = −0.5569, p < 0.01) ( Ahmad et al., 2022 ), etc.…”

Antagonism of Rhizosphere Streptomyces yangpuensis CM253 against the Pathogenic Fungi Causing Corm Rot in Saffron (Crocus sativus L.)

“…There have been numerous studies on the prevention and control of crocus corm rot and the advancement of crocus yields and quality by beneficial strains. For example, Burkholderia gladioli E39CS3, an endophytic bacteria of C. sativus , has been shown to inhibit the in vivo corm rot of F. oxysporum , a specific pathogen of C. sativus , and to induce systemic drug resistance (ISR) [ 37 ]. Curtobacterium herbarum , Cs10, improves the number of flowers and significantly enhances the length of the saffron filaments and the overall saffron production [ 38 ].…”