From cotton genomics to functionomics via Agrobacterium-Mediated VIGS Assay

Functional Genomics

oral

Shan, Libo

Shan, Libo

Shan, Libo

From cotton genomics to functionomics via Agrobacterium-Mediated VIGS Assay Libo Shan Department of Plant Pathology and Microbiology Institute of Plant Genomics and Biotechnology Texas A&M University lshan@tamu.edu As an economically important crop, cotton (Gossypium spp.) serves as a significant source of textile fiber, feed and oil products worldwide. Cotton production is hindered by various biotic and abiotic stresses. The genetic and molecular mechanisms mediating cotton stress responses remain poorly understood. We have previously developed an Agrobacterium-mediated virus-induced gene silencing (VIGS) assay in several cotton cultivars. The genes of interest could be potently and readily silenced at the seedling stage with a consistently high efficiency. To monitor gene silencing efficiency, we have cloned cotton GrCla1 from G. raimondii, a homolog gene of Arabidopsis Cloroplastos alterados 1 (AtCla1) involved in chloroplast development. Silencing of GrCla1 results in albino phenotype on the newly emerging leaves, serving as a visual marker for silencing efficiency. To further facilitate cotton functional genomic studies and identify cotton genes mediating biotic and abiotic stress responses, we constructed a VIGS library from diploid cotton G. raimondii. Sequencing of the representative colonies revealed that the library covers a significant percentage of cotton unique genes with about 50X coverage of predicted cotton protein-coding genes. As a proof-of-concept experiment, we screened the genetic determinants involved in cotton drought tolerance using this VIGS library. We further established a cotton protoplast system to study gene functions by a gain-of-function approach. These technique advances made it possible to dissect the molecular and biochemical regulatory mechanisms of cotton genes under different biotic and abiotic stresses.