Chiu-Ping Cheng
National Taiwan University, Taiwan
Title: Study of the mechanisms underlying tomato innate immunity mediated by two Bwr12 genes
Biography
Biography: Chiu-Ping Cheng
Abstract
Bacterial wilt (BW) caused by Ralstonia solanacearum (Rs) is a devastating disease of many crops, and breeding for durable resistance is urgent and important for disease control. Tomato cultivar Hawaii 7996 (H7996) is currently the most stable resistance source for BW control. Although various BW-resistance-associated quantitative trait loci (QTLs) have been mapped on H7996 chromosomes, the involved molecular mechanisms and the gene identities remain undetermined. Our studies showed that H7996 possesses strong PTI responses, and the major QTL associated with the H7996 resistance against Rs phylotype I strains, namely Bwr12, is involved in PTI. Functional genetic and gene expression analyses further revealed positive roles of Bwr12-A and Bwr12-B in PTI and defense against distinct pathogens. Transient expression assay suggested that 12g520 localizes on the plasma membrane of Nicotinana benthamiana (Nb), while 12g550 might localize on the cell membrane, nucleus or be secreted to the apoplast. Overexpression of 12g550 in transgenic Nb increased H2O2 accumulation and resistance to Rs and Pectobacterium carotovorum subsp. carotovorum (Pcc). In addition, 12g520 might not interact with SlSERK3A, SlSERK3B, and SlFLS2 under normal conditions. These results along with future studies are projected to shed light on H7996 defense mechanisms.