Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: The Botrytis cinerea xylanase Xyn11A contributes to virulence with its necrotizing activity, not with its catalytic activity | Noda et al. BMC Plant Biology 2010 10 38 http 1471-2229 10 38 BMC Plant Biology RESEARCH ARTICLE Open Access The Botrytis cinerea xylanase Xyn11A contributes to virulence with its necrotizing activity not with its catalytic activity Judith Noda Nélida Brito Celedonio Gonzalez Abstract Background The Botrytis cinerea xylanase Xyn11A has been previously shown to be required for full virulence of this organism despite its poor contribution to the secreted xylanase activity and the low xylan content of B. cinerea hosts. Intriguingly xylanases from other fungi have been shown to have the property independent of the xylan degrading activity to induce necrosis when applied to plant tissues so we decided to test the hypothesis that secreted Xyn11A contributes to virulence by promoting the necrosis of the plant tissue surrounding the infection therefore facilitating the growth of this necrotroph. Results We show here that Xyn11A has necrotizing activity on plants and that this capacity is conserved in site-directed mutants of the protein lacking the catalytic activity. Besides Xyn11A contributes to the infection process with the necrotizing and not with the xylan hydrolyzing activity as the catalytically-impaired Xyn11A variants were able to complement the lower virulence of the xynllA mutant. The necrotizing activity was mapped to a 30-amino acids peptide in the protein surface and this region was also shown to mediate binding to tobacco spheroplasts by itself. Conclusions The main contribution of the xylanase Xyn11A to the infection process of B. cinerea is to induce necrosis of the infected plant tissue. A conserved 30-amino acids region on the enzyme surface away from the xylanase active site is responsible for this effect and mediates binding to plant cells. Background Botrytis cinerea is a phytopathogenic fungus with a wide host range and a necrotrophic life style for a review see 1-3 . As part of its invasion strategy B. cinerea and other .
