Transformation of Potato (Solanum tuberosumcv.Savalan) by Chitinase and β-1,3-Glucanase Genes of Myco-Parasitic Fungi Towards Improving Resistance to Rhizoctonia solani AG-3

Potato (Solanum tuberosum L.) an agro-economically important food crop in the world, is sensitive to many fungal pathogens including Rhizoctonia solani (AG-3), the causal agent of stem and root rot diseases. Chitinase and glucanase are cell wall degrading enzymes which have been shown to have high antifungal activity against a wide range of phytopathogenic fungi. In the present study, plasmid pBIKE3 harboring a double-gene cassette containing the chitinase (chit42) and b-1,3-glucanase (bgn13.1) genes was constructed. In this construct, the chit42 gene is located between the CaMV 35S promoter and nos terminator derived from pBI121, while the bgn13.1 gene is downstream of a modified CaMV 35S promoter, followed by the nos terminator both of which were derived from the pRTL plasmid. Micro-tubers of potato plants (the Savalan cultivar) were transformed with the pBIKE3 construct via the Agrobacterium delivery system. Integration of these two genes into the potato genome and their expression at the transcriptional level was confirmed by polymerase chain reaction (PCR) and reverse transcription-PCR (RT-PCR). The radial diffusion assay showed that the heterologous expressed chitinase and glucanase enzymes demonstrated antifungal activity on R. solani (AG-3).