Antioxidant enzymes in chickpea colonized by Piriformospora indica participate in defense against the pathogen Botrytis cinerea

Om Prakash Narayan,Meenakshi Dua,Nidhi Verma,Manoj Kumar,Alok Kumar Singh,Durga Prasad,Rupam Kapoor,Atul Kumar Johri,Ralf Oelmüller

doi:10.1038/s41598-017-12944-w

Abstract

Piriformospora indica, a root endophytic fungus, promotes growth of the economically important chickpea plant (Cicer arietinum Linn.) and protects it against the pathogenic fungus Botrytis cinerea. Biomass and root development were found to be significantly improved in chickpea plants colonized with P. indica as compared to the plants grown without P. indica as well as from the plants infected with the B. cinerea. Our PCR analyses showed that gradual increase in the colonization of P. indica in the plants result in the inhibition of the colonization of B. cinerea. P. indica colonized plants showed increased antioxidant enzyme activities. Interestingly, there were pronounced decrease in the antioxidant enzyme activities in shoots infected with B. cinerea and colonized with P. indica in alternate and simultaneous mode as compared to plants infected with B. cinerea alone. We conclude that P. indica helps plants to overcome the disease load by enhancing antioxidant enzyme defense system. Our data suggest that, bio-protective action of P. indica might be mediated via systemic induction of antioxidant defense in the host plants.

Highlights

Mycorrhizal associations are very important for a wide range of plants
We have observed increased length of crown roots and more number of secondary roots in case of plants first inoculated with P. indica and 10 days later infected with B. cinerea as compared to chickpea plants which were not colonized either with B. cinerea or P. indica and this difference was found to be significant (P < 0.05) (Fig. 2C,D)
A similar trend was observed when the plants were first infected with B. cinerea and at day 10 inoculated with P. indica, or when both fungi were applied simultaneously as compared to the plants infected with the B. cinerea only (P < 0.05) (Fig. 2C,D)

Summary

Introduction

Mycorrhizal associations are very important for a wide range of plants. They are broadly categorised into endomycorrhiza and ectomycorrhiza[1]. Arbuscular Mycorrhizal Fungi (AMF) are obligate biotrophs and colonize root cells when they get a specific response from the plants. Through this association both partners fulfil their nutritional demands. P. indica associated plants showed a high level of antioxidant enzyme activities which protect plants from oxidative damage. P. indica inoculated plants showed an increase in SOD, GR, CAT and GST activities[19,20] which help plants to overcome infections and stresses. They might participate in promoting plant growth by keeping the ROS level below a critical threshold[21]. To know how P. indica help the infected chickpea plants to overcome disease load of B. cinerea, tripartite interaction of P. indica, B. cinerea and chickpea plants and the role of antioxidant enzymes have been investigated in this study

Methods

Results

Conclusion