Tomato mutants altered in bacterial disease resistance provide evidence for a new locus controlling pathogen recognition.
Tomato mutants altered in bacterial disease resistance provide evidence for a new locus controlling pathogen recognition.
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细菌抗病性改变的番茄突变体为控制病原体识别的新基因座提供了证据。
DOI：
10.1105/tpc.6.4.511
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Staskawicz,BJ
中科院分区：
文献类型：
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作者：
Salmeron,JM;Barker,SJ;Carland,FM;Mehta,AY;Staskawicz,BJ
我们采用遗传方法研究了番茄对植物病原菌Pusomonas syringae PV的抗性。番茄对P.S.番茄的抗性取决于PTO基因在番茄中的表达，该基因编码一种与丝氨酸/苏氨酸蛋白激酶相似的蛋白，并识别表达无毒基因avrPto的病原菌。共分离到11个番茄突变体，它们对表达avrPto的P.S.番茄菌株的抗性发生了变化。我们鉴定了PTO抗性基因座和一个名为PrF(假单胞菌抗性和杀菌硫磷敏感)的新基因座上的突变。遗传学方法使我们能够剖析这些基因座在响应病原体攻击的信号转导中的作用。携带PTO基因座突变的品系对表达avrPto的P.S.番茄菌株的易感程度不同，差异达200倍。PTO突变体对有机磷杀虫剂苯硫磷保持敏感；在遗传杂交中，这一性状与PTO分离。这一结果表明，与先前的假设相反，PTO基因座控制病原菌识别，但不控制杀硫磷的敏感性。有趣的是，PrF基因突变导致番茄对P.S.番茄完全敏感和对杀菌硫磷不敏感，这表明PrF基因在番茄对病原菌激发子和杀菌硫磷的反应信号中发挥了作用。由于PtO和PrF突变不会改变表达avrBsP的野油菜黄单胞菌菌株的识别能力，PrF在抗病中不起普遍作用，但可能在抗S番茄疫病中起特异性作用。对PTO纯合子和PRF纯合子杂交F2群体的遗传分析表明，PTO和PRF基因座紧密连锁。
We have employed a genetic approach to study the resistance of tomato to the phytopathogenic bacterium Pseudomonas syringae pv tomato. Resistance to P. s. tomato depends upon expression of the Pto locus in tomato, which encodes a protein with similarity to serine/threonine protein kinases and recognizes pathogen strains expressing the avirulence gene avrPto. Eleven tomato mutants were isolated with altered resistance to P. s. tomato strains expressing avrPto. We identified mutations both in the Pto resistance locus and in a new locus designated Prf (for Pseudomonas resistance and fenthion sensitivity). The genetic approach allowed us to dissect the roles of these loci in signal transduction in response to pathogen attack. Lines carrying mutations in the Pto locus vary 200-fold in the degree to which they are susceptible to P. s. tomato strains expressing avrPto. The pto mutants retain sensitivity to the organophosphate insecticide fenthion; this trait segregates with Pto in genetic crosses. This result suggested that contrary to previous hypotheses, the Pto locus controls pathogen recognition but not fenthion sensitivity. Interestingly, mutations in the prf locus result in both complete susceptibility to P. s. tomato and insensitivity to fenthion, suggesting that Prf plays a role in tomato signaling in response to both pathogen elicitors and fenthion. Because pto and prf mutations do not alter recognition of Xanthomonas campestris strains expressing avrBsP, an avirulence gene recognized by all tested tomato cultivars, Prf does not play a general role in disease resistance but possibly functions specifically in resistance against P. s. tomato. Genetic analysis of F2 populations from crosses of pto and prf homozygotes indicated that the Pto and Prf loci are tightly linked.