Polyamine Modulation by antagonistic bacteria Bacillus subtilis in chickpea during Fusarium oxysporum f. sp. ciceri interaction

Abstract

Chickpea (Cicer arietinum L.) is pivotal source of protein for vegetarian diet, however, its productivity is adversely affected by wilt disease. Non pathogenic rhizospheric microorganism’s leads to induce resistance and are found to be effective in management of this disease. The polyamines (PAs) content and its metabolism are the key in plant microbial interaction, so the alteration in PAs viz. spermidine (SPD), spermine (SPM) and putresine (PTR) in chickpea by Bacillus substilis isolate K18 (BS-K18) effective antagonist (75%) of Fusarium oxysporum f. sp. ciceri (Foc) and having PGPR traits was analyzed under Foc stress. The higher PAs content was reported in resistant variety (WR-315) compared to susceptible variety (JG-62). The PTR was dominant PA present in chickpea, further overall root tissue reported higher PA content as compared to leaves tissue. The PA content was constitutively improved by B. subtilis seed treatment in resistant and susceptible varieties. The Foc stress leads to induction of PA content in leaves and root tissue, where its content was higher in resistant variety as compared to susceptible variety. The BS-K18 seed treatment under Foc stress leads to induction of PA content as compared to both treatments alone, the SPD and SPM were more induced in leaves and root tissue of susceptible variety whereas PTR was more induces in resistant variety. Overall, polyamines were induced up to 3 DAT then after decline suggest their early role in plant defence mechanism, further PTR was found to be dominating polyamine during chickpea-Foc interaction under BS-K18 treatment. The Bacillus subtilis seed treatment leads to improve wilt tolerance in susceptible var. JG-62 through modulation of PAs, the same mechanism also helped to enhanced effectiveness of resistant var. WR-315.