Molecular Analysis of Disease-Responsive Genes Revealing the Resistance Potential Against Fusarium Wilt (Fusarium udum Butler) Dependent on Genotype Variability in the Leguminous Crop Pigeonpea.

Koushik Biswas,Mamta Sharma,Avijit Tarafdar,Pratyoosh Shukla,Sunil Pabbi,Roshan Kumar,Nirjara Singhvi,Parthadeb Ghosh

doi:10.3389/fgene.2020.00862

Abstract

Fusarium wilt (FW), caused by Fusarium udum Butler (FU), is among the challenging factors in the production of pigeonpea. Therefore, exploring a superior pigeonpea genotype from landraces or local cultivars through the selection of innate resistance to FW using different biological and molecular approaches, and validating its resistance response, could be an alternative to sustainable crop improvement. Five distinct pigeonpea genotypes, with resistant (ICP2894) and susceptible (ICP2376) controls, were selected on the basis of the incidence percentage of FW, from three different states of India. Among them, the cultivar Richa, which displayed low incidence of FW (10.0%) during the genotype evaluation, was further examined for its innate resistance to FW. Molecular characterization of antioxidant (AO) enzyme [APX and SOD] and pathogenesis-related (PR) protein [CHS and β-1, 3-glucanase] families were performed. The obtained results of reverse transcription-polymerase chain reaction-based expression study and in silico analysis showed a higher level of induction of PR and AO genes, and the strong interaction of their putative proteins with fungal cellobiohydrolase-c protein established their antifungal activity, conferring early plant defense responses to FU in Richa. Our study demonstrated a strong and combinatorial approach involving biological assay, molecular experiments, and in silico analysis to identify a superior pigeonpea genotype that was resistant to FW across a major biogeographic region.

Highlights

The global population is continuously increasing and is projected to increase further by 3.5 billion by the end of this century, to an estimated number of 11.2 billion (Max, 2019), resulting in increased demand for food grains
To understand the epidemiological intensity of the disease in each village of the respective surveyed district, the DI% range was further graded into five categories viz., very less infestation (VLI) (0.5–5%); less infestation (LI) (5.1–10.0%); moderately infestation (MI) (10.1–15%); high infestation (HI) (15.1–20%); and very high infestation (VHI) (>20.1) (Table 1)
Fusarium wilt (FW) is a vital ailment of pigeonpea and is recognized to be the worst hindrance in the cultivation of this crop in India (Singh, 2009)

Summary

Introduction

The global population is continuously increasing and is projected to increase further by 3.5 billion by the end of this century, to an estimated number of 11.2 billion (Max, 2019), resulting in increased demand for food grains. Pigeonpea belongs to the family Fabaceae and contributes by fulfilling the protein demand of approximately 20% of the global population. It serves as a major source of vitamins. A major restraint in pigeonpea production has been caused by biotic stresses, among which, Fusarium wilt (FW) is considered to be the most devastating disease, followed by sterility mosaic disease and Phytophthora blight. The former accounts for 30–100% losses in the yield of pigeonpea genotypes that are vulnerable to this disease (Pande et al, 2011)

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