用免疫组织化学染色法检测棉花幼苗根尖的枯萎病抗性蛋白质

Detection of a Race-Specific Resistance Protein in Primary Root of Wilt-Resistant Cotton by Immunohistochemical Staining

我们实验室在棉花枯萎病的工作中从川-52128等抗病棉花品种里纯化、鉴定了一个具有生理小种(生理型)特异性的、组成型表达的抗病蛋白质R,其特异性与这个棉花品种在田间的抗病表型一致。蛋白质R在体外(7μg/ml)能抑制不亲和的棉枯萎病镰刀菌[Fusarium oxysporum f.sp.vasinfectum(ATK)Snyder & Hansen]孢子的萌发和菌丝体的生长。从感病棉花品种中也纯化了一个与蛋白质R相对应的蛋白质S。

Previous studies showed that a race-specific protein R resistant to cotton Fusarium-wilt was identified and purified from resistant cultivars. The protein inhibits the growth of mycelia and the germination of spores of incompatible races, but not compatible ones, of Fusarium oxysporum f. sp. vasinfectum (ATK) Snyder & Hansen. A protein S from wilt-susceptible cultivars very similar to protein R in polyacrylamide gel electrophoretic and isoelectrofocusing behavior but without inhibitory effects was also purified. Both protein R and S were isolated from leaves. By reason of the main invasion pathway of the pathogen into cotton is via roots but not via leaves, whether protein R is expressed in the root is a critical problem in understanding the biological function of protein R. This report showed that protein R is expressed constitutively in primary root, especially in apical meristem which may develop into vascular tissue. The pathogen extends to the top of cotton along with vascular tissue. The results of staining also lead to the proposal that protein R may be located on the cell surface.