Analysis of a Tomato Pseudomonas Resistance Locus, Pto

小行星9303359 本研究的长期目标是阐明植物抗病基因的功能。 番茄与病原细菌假单胞菌的互作。 番茄（Pst）为理解基因对基因互补性提供了一个理想的系统。 番茄中对Pst的抗性由单个定位的基因座Pto赋予，并且已经分离出对应于Pto的avr基因（avrPto）。 一个多步骤的位置克隆策略最近已被用来确定酵母人工染色体（YAC）克隆，含有Pto基因座。 我们现在建议从YAC克隆中分子分离Pto基因座，并表征其在抗性中的作用。 我们将分离Pto细菌抗性基因座;确定Pto的DNA序列并检查其结构特征;调查易感植物中存在的Pto潜在的替代等位基因;表征Pto基因的时空表达模式;使用Pto等基因系检查病程相关（PR）基因和其他防御相关基因的表达模式，并确定Pto蛋白的空间和时间积累模式。 了解Pto基因的DNA序列及其基因产物在植物细胞中的定位将解决细胞间相互作用的基本问题。 此外，由于Pto基因将可能是第一个分离的植物抗病基因之一，它的特性可能有助于从其他植物物种中分离抗病基因。 ***

9303359 Martin The long term objective of this research is to elucidate the function of plant disease resistance (DR) genes. The interaction of tomato and the bacterial pathogen Pseudomonas syringae pv. tomato (Pst) provides an ideal system for understanding gene-for- gene complementarity. Resistance to Pst in tomato is conferred by a single, mapped locus, Pto and an avr gene corresponding to Pto has been isolated (avrPto). A multi-step positional cloning strategy has recently been used to identify a yeast artificial chromosome (YAC) clone that contains the Pto locus. We now propose to molecularly isolate the Pto locus from this YAC clone and characterize its role in resistance. We will isolate the Pto bacterial resistance locus; determine the DNA sequence of Pto and examine its structural features; investigate potential alternate alleles of Pto that exist in susceptible plants; characterize the spatial and temporal expression patterns of the Pto gene; examine the expression patterns of pathogenesis-related (PR) genes and other defense-related using Pto isogenic lines, and determine the spatial and temporal accumulation patterns of the Pto protein. %%% Knowledge of the DNA sequence of the Pto gene and the localization of its gene product in the plant cell will address fundamental questions in cell-cell interactions. In addition, since the Pto gene will likely be one of the first plant resistance genes isolated, its characterization may facilitate the isolation of disease resistance genes from other plant species. ***