Pflp gene transformation in pomegranate (Punica granatum L.) resistance to bacterial blight disease (Xanthomonas axonopodis pv. punicae)

Abstract

Pomegranate ( Punica granatum L.) is a woody perennial fruit crop grown in arid zones of India, the state of Maharashtra being considered as pomegranate basket contributes to 70 % of the total area followed by Karnataka and Andhra Pradesh. Protection of crops against bacterial disease is an important issue in agricultural production. Pomegranate production in India is severely hampered by the high incidence of bacterial blight disease caused by Xanthomonas axonopodis pv. punicae is air borne, the conventional ways and means of controlling this disease have failed. Evolving a resistant genotype using resistant variety through conventional breeding may be a way out but it is a time consuming process. Transgenic approach appears to be promising to minimize the losses caused by disease. In the present investigation efficient protocols were developed to get healthy and well-formed plants from juvenile and mature-origin explants of the pomegranate cv. ‘Bhagwa’ and transformants with PFLP gene. One of the strategies to lead plants become resistant against bacterial pathogens is employing a transgene, like plant ferredoxin-like protein (PFLP). Different treatment combinations of hormonal concentrations were taken for leaf, petal, nodes and cotyledonary explants to standardize an efficient in vitro regeneration protocol and find out the best treatment for faster regeneration. Agrobacterium tumefaciens carrying gene pCAMBIA construct with the constitutive CaMV35S promoter, PFLP gene, terminator and nptII selectable marker (Kanamycin resistance), was used for transformation of explants. Putative transformants were identified on selection medium containing kanamycin at different concentration. Integration of transgene and expression at various levels were confirmed using PCR. Out of 4 putative transformants analyzed, three plants showed amplification for PFLP gene specific primer. Key words In vitro , Pflp gene, transformation, bacterial blight disease, putative transformants, Agrobacterium tumefaciens