Executive Summary : | It is well known that plant viruses pose a major threat to various plant species in agriculture. They are difficult to control due to frequent changes in their genome through mutation and genetic recombination. Genetic resistance is a suitable and practical approach for controlling viral diseases. Natural genetic resistance is rare and to develop novel genetic basis of resistance, it is imperative to understand the viral infection process. Virus infection in plants is a complicated process which requires specific interactions between viral and host proteins. Due to the complexity of plant genomes and the diversity of plant viruses, identification of the host proteins in such interactions is limited. Nanoviruses are economically important plant viruses that affect horticultural crops in tropical and sub-tropical areas worldwide. These viruses are categorized in the Nanoviridae family, consisting of small, circular, single-stranded DNA (ssDNA) viruses with the multipartite genome. Due to limited coding capacity, nanoviral genome only encodes 6-7 proteins to complete their life cycle in a permissive host. However, as evolutionarily successful pathogens, nano viruses can replicate efficiently within the host cells hijacking their intrinsic molecular machinery. They have evolved with the ability to take over host proteins and modulate host metabolites to support the infection process. Banana is one of the most important fruit crop in India and accounts for 36.6 percent of the total fruit production. It is widely cultivated in varying agro-climatic regions under different systems of production. However, banana cultivation continues to face several pests and disease issues, leading to a decline in production. Viral diseases are a major concern because of high yield loss, reduced quality, and limitations in planting material multiplication, among other reasons leading to lower productivity. More than 20 viruses are reported in banana plants globally. Among them, the most important group of viruses are Banana bunchy top virus (BBTV), Banana bract mosaic virus (BBrMV), Banana streak viruses (BSV), and Cucumber mosaic virus (CMV). Recent studies have highlighted that BBTV is the most economically damaging virus contributing to a yield reduction of up to 100?%. Therefore, screening banana germplasm for resistance against this virus will provide useful omics resources for future breeding and molecular interventions. Focusing on this, the primary objective of this proposal is to characterize the germplasm accessions collected for virus tolerance. The identified contrasting genotypes (highly tolerant and highly susceptible) would be evaluated through transcriptome analysis. The final prospect of this project would include identifying genes involved in defense against BBTV. The target genes involved in the plant defense would be comparatively studied among the tolerant and susceptible genotypes to develop resistant planting material in banana. |