<i>Streptomyces rochei </i><scp>SM</scp>3 Induces Stress Tolerance in Chickpea Against <i>Sclerotinia sclerotiorum</i> and NaCl

Abstract

Abstract Understanding on actinomycetes‐mediated stress tolerance in plants is very limited. This study demonstrated for the first time some stress tolerance mechanisms in chickpea via mediation of an actinomycetes strain S treptomyces rochei SM 3. Here, we used the strain SM 3 for treating chickpea seeds and plants raised from such seeds were challenged with Sclerotinia sclerotiorum and NaCl. Chickpea mortality due to Sc. sclerotiorum infection was suppressed by nearly 48%, and biomass accumulation was increased by nearly 20% in the salt‐stressed condition in SM 3‐treated plants compared to non‐treated plants. Physiological responses in chickpea under the challenging conditions showed that phenylalanine ammonia lyase activities increased in SM 3‐treated plants. This is followed by accumulation of higher concentrations of phenolics that led to enhanced lignifications in SM 3‐treated plants compared to non‐ SM 3‐treated plants challenged with the same stresses. Antioxidant activities, as assessed through catalase activities and proline accumulation, also increased in SM 3‐treated plants challenged with both the stresses compared to non‐ SM 3‐treated plants. Investigation at genetic level further showed that the strain SM 3 triggered the ethylene ( ET ) responsive ERF transcription factor ( C a TF 2 ) under the challenged conditions. Thus, from this study, we conclude that actinomycetes St. rochei SM 3 trigger the ET ‐mediated defence pathway in chickpea and activates the phenylpropanoid pathway for alleviating the stresses caused by Sc. sclerotiorum and salt in chickpea.