Comparative analysis of disease resistance and defense response genes in pigeonpea

Abstract

Pigeonpea (Cajanus cajan (L.) Millsp.) belongs to the plant family Fabaceae newlinewith diploid chromosome number (2n= 22) and genome size of 858 Mb. It is world s newlinefourth most important food legume crop and popularly known as Red gram , Toor newlineand Arhar in South Asian countries where it has originated and cultivated widely as newlinefood crop. It is a major pulse crop of tropical and sub-tropical countries including newlineIndia, Myanmar, Malawi, Tanzania, Kenya, Uganda, West Indies and South Africa. newlinePigeonpea is an important legume crop that can be used as an antidote to proteincalorie malnutrition in South Asia, South-East Asia and East Africa, owing of its newlinerichness in protein, vitamins, minerals, and essential metabolites. Pigeonpea faces newlineextensive losses in productivity because of various diseases caused by fungi, bacteria, newlineviruses and nematodes. Plant s sophisticated immune system includes a variety of newlinestructural basal and inducible defense mechanisms. The major components of basal newlinedefense mechanism are bark, waxy epidermal. In inducible defense mechanisms, the newlinefirst defense response includes pattern recognition receptors, known as pathogen newlineassociated molecular patterns (PAMPs). The second defense response is associated newlinewith cytoplasmic immune receptors, which activate signaling recognize pathways that newlinelead to a hypersensitive response (HR). The hypersensitive response is a strategy used newlineby the plants against pathogen and is characterized by interaction between specific newlinedisease resistance (R) genes of plant and its corresponding avirulence (Avr) genes of newlinethe pathogen. Defense response genes code for pathogenesis-related (PR) proteins, newlinewhich play important role in plant disease resistance against a range of biotic and newlineabiotic stresses. Exploitation of the host resistance appears to be the most reliable and newlineeconomically viable strategy for disease management. Owing to the huge economical, newlinenutritional, medicinal and socioeconomic importance of pigeonpea there is a need to newlinedevelop new and improved resistance varieties of pigeonp