Plants are constantly exposed to different abiotic and biotic stresses during their lifetime. Among the most important stress factors are pathogenic microorganisms causing diseases. This has lead to the development of elaborate resistance mechanisms by plants and sophisticated virulence mechanism by pathogens during their co-evolution. The exploitation of disease-resistance mechanisms leading to durable protection is one major objective of centemporary plant breeding and biotechnology. However, in order to achieve this goal much has yet to be learned about molecular plant-pathogen interactions.
High throughput sequencing of genomes and transcriptomes has revolutionized and accelerated the pace and progress of research across the life sciences. In plants, the application of these approaches to model organisms and major agricultural crops has provided tremendous insight into plant-pathogen interaction. These technologies are thus paving the way for whole genome transcriptomics and will undoubtedly lead to novel insights into plant development and biotic and abiotic stress responses.
Ginger (Zingiber officinale) is affected by many diseases. Among them, bacterial wilt (Ralstonia solanacearum) is one of the most important production constraints in tropical, sub tropical and warm temperature regions of the world. In spite of extensive search, no resistance source could be located in ginger. However, mango ginger (Curcuma amada), which is resistant to R. solanacearum, is a potential donor, if the exact mechanism of resistance is understood. Although ESTs and other cDNA sequences are among the most reliable evidences for the identification of gene-rich regions in a genome, gene identification and genome annotation, very less effort has been made for ginger-pathogen interaction. Our objective is deep sequencing of transcriptomes of both genotypes followed by de novo assembly and annotation.
The transcriptome has been sequenced from rhizome tissue samples after challenge inoculation with R. solanacearum using next generation technologies for short read (Illumina platform). It involves analysis of GC content, repeat content, putative functions, gene families, transcription factor encoding genes and its comparative analysis with and C. amada. The identification of many defense related genes differentially expressed provides many insights to resistance mechanism to R. solanacearum and for studying pathways involved in responses to pathogen. We also identified several candidate genes that may underline the difference in resistance to R. solanacearum between ginger and mango ginger.