Isolation and molecular charcterisation of pathogen inducible gene and promoters with its cis element from pathogenesis related gene in brassica juncea

Abstract

newlinePlants are challenged by a variety of biotic stresses like fungal, bacterial, and viral infections. newlineThis lead to a great loss to plant yield. Among these biotic stresses fungi are important newlinepathogens causing major yield losses in cereals, pulses, oil seed crops, vegetables and fruits newlineleading to severe crop losses both in quantity and quality. It is estimated that, at least 125 newlinemillion tones of crop harvest has been vanished every year due to major biotic stresses. This newlineis sufficient to feed at least 600 million people across the world. Brassicaceae is the crucifer newlineplant family consists of about 3500 species in 350 distinct genera. Brassica juncea (n =18) is newlinean amphidiploids species derived from interspecific crosses between Brassica nigra (n = 9) newlineand Brassica Rapa (n = 10). Indian mustard (Brassica juncea L. Czem and Coss) is one of newlinethe most important oil seed crops of the country and contributes more than 80% to the total newlinerapeseed mustard production (Vinu et al, 2013) and fulfills nearly 27% of vegetable oil newlinerequirements of the country (Giri et al, 2013). It is cultivated in an area of 7 million hectares newlineof land with a production of 0.81 million tones and with an average yield of 1149 kg/ha newline(Anon., 2006). India is one of the secondary centers of diversity for B Juncea where it is well newlineadapted to varied agro climatic conditions of northern India. One of the major constraints on newlineproductivity of this crop is damage due to Altemaria leaf spot, which is caused by Alternaria newlinebrassicae (Mishra et al, 2010). Depending upon severity, the yield losses have been newlineestimated to range from 35% to 46% (Mishra et al, 2010) in India and up to 70% all over the newlineworld with no proven source of transferable resistance in any of the hosts (Vishwanath and newlineKolte, 1997). A. brassicae produces light brown to greyish or dark brown spots with newlinecharacteristic concentric rings and surrounded by chlorotic areas on the leaves, stem and newlinesiliquae causing reduction in the photosynthetic areas, defoliation and early induction of newlinesenescence. A. brassicae is a necrotrophic pathogen (Tewari, 1991) and little is known about newlinethe necrotrophic pathogenesis mechanisms compared to that of other biotrophic and semibiotrophic pathogens such as Peronospora parasitica and Pseudomonas syringae, newline