Max-Planck-Institut für Züchtungsforschung, Abteilung Biochemie, Carl-von-Linné-Weg 10, 50829 Köln, Germany.
Mol Plant Pathol. 2002 Sep 1;3(5):329-45. doi: 10.1046/j.1364-3703.2002.00126.x.
Summary The infection of potato (Solanum tuberosum) leaves with the late blight pathogen Phytophthora infestans, or treatment with fungal elicitor, leads to the massive accumulation of pathogenesis-related (PR) proteins in the extracellular leaf space. The most abundant of these proteins was purified to apparent homogeneity and identified as a new, basic member of the PR-1 family of defence proteins, designated PR-1b. Antibodies raised against the protein and a cDNA isolated by differential screening were used to study the temporal and spatial patterns of PR-1b protein and mRNA distribution in healthy and infected potato tissues. PR-1b was present in old leaves and at low levels also in the carpels of flowers. In leaves, strong accumulation of PR-1b mRNA and protein occurred in response to infection by the oomycete pathogen Phytophthora infestans or the bacterial pathogen Pseudomonas syringae pv. maculicola. PR-1b mRNA and protein accumulation was clearly initiated at the infection site, but a delayed and sustained accumulation was also observed in neighbouring, uninfected leaves of potato plants. Tissue- and cell type-specific expression of PR-1b was analysed by immunohistochemical and in situ RNA hybridization techniques. Appreciable amounts of PR-1b protein and mRNA were localized in epidermal cells, guard cells of the stomata, glandular trichomes, crystal idioblasts, and cells of the vascular system of infected leaves. However, no significant differences in the amounts and distribution patterns of PR-1b could be observed between compatible and incompatible interactions of potato and Phytophthora infestans, indicating that PR-1b expression is not involved in determining cultivar/race-specific resistance in potato.
摘要 感染晚疫病菌（Phytophthora infestans）或用真菌诱导子处理马铃薯叶片会导致细胞外叶空间中大量积累病程相关（PR）蛋白。这些蛋白中最丰富的一种被纯化至明显的均一性，并被鉴定为 PR-1 家族防御蛋白的一个新的碱性成员，命名为 PR-1b。针对该蛋白产生的抗体和通过差异筛选分离的 cDNA 被用于研究 PR-1b 蛋白和 mRNA 在健康和感染的马铃薯组织中的时空分布模式。PR-1b 存在于老叶中，在花的雌蕊中也以低水平存在。在叶片中，对卵菌病原体晚疫病菌或细菌病原体丁香假单胞菌 pv. maculicola 的感染会强烈积累 PR-1b mRNA 和蛋白。PR-1b mRNA 和蛋白的积累显然是在感染部位开始的，但在马铃薯植株的邻近未感染叶片中也观察到延迟和持续的积累。通过免疫组织化学和原位 RNA 杂交技术分析 PR-1b 的组织和细胞类型特异性表达。在感染叶片的表皮细胞、气孔的保卫细胞、腺毛、晶体异形细胞和维管束系统中可检测到相当数量的 PR-1b 蛋白和 mRNA。然而，在马铃薯与晚疫病菌的亲和和非亲和互作之间，PR-1b 的数量和分布模式没有明显差异，表明 PR-1b 的表达不参与决定马铃薯品种/小种特异性抗性。
