GhLaccase from G. hirsutum is involved in lignin content alteration and Verticillium wilt resistance

Working group session: 
Functional Genomics
Presentation type: 
poster
Authors: 
Wu, Lizhu ; Wang, Xingfen; Zhang, Chunying ; Zhang, Yan ; Yang, Jun ; Zhang, Guiyin ; Ma, Zhiying
Presenter: 
Wu, Lizhu
Correspondent: 
Ma, Zhiying
Abstract: 
Lignin metabolism has a central role in the cotton resistance to wilt fungus V. dahliae. Here, we cloned a gene, GhLaccase (G. hirsutum laccase, EU642559.1), from the Verticillium-wilt-tolerant cotton. Bioinformatics analysis showed that a cleaved signal sequence, MGLQQGFVTWFVGVLFLTTLLLSSA, existed in N-terminal of GhLaccase protein. The GhLaccase protein was located in cell wall, suggesting that GhLaccase performed its active in extracellar. The expression of GhLaccase in tolerant cotton cv. Jimian20 increased 8-14 fold compared to that of control and peaked in 8 hr post inoculation with V. dahliae. Silencing of GhLaccase in the cotton by VIGS method declined the Verticillium wilt tolerance, and over-expression of GhLaccase enhanced the resistance in Arabidopsis. The contents of Klason lignin, total lignin and guaiacyl monomers (G monomers) in transgenic Arabidopsis over-expression lines were highly significant higher (P<0.01) than those of wild type inoculated with V. dahliae or not. Our results showed that GhLaccase from G. hirsutum was involved in lignin content alteration and Verticillium wilt resistance.