A lesion-mimic mutant of wheat with enhanced resistance to leaf rust
A lesion-mimic mutant of wheat with enhanced resistance to leaf rust
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DOI：
10.1111/j.1365-3059.2006.01454.x
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发表时间：
2007-02-01
期刊：
影响因子：
2.7
通讯作者：
Acevedo, A.
中科院分区：
文献类型：
--
作者：
Kamlofski, C. A.;Antonelli, E.;Acevedo, A.
对阿根廷面包小麦（Triticum aestivum）品种Sinvalocho ma进行甲基磺酸乙酯诱变处理，获得了一个类似病变的突变体。HLP（超敏样表型）突变体在没有任何病原体的情况下表现出微小、离散的白色病变，类似于典型的超敏反应（HR）。只有在第五片或第六片叶子出现时，病变才变得明显，并沿着发育中的植物的叶片和叶鞘随机扩散，包括穗的组织。由于病变模拟突变体在苗期没有病变，因此突变体和母系在这一点上的表型是相同的。组织化学研究表明，HLP突变体中自发的超敏样病变与细胞死亡相对应。在幼苗期和成株期进行的叶锈病（小麦锈病）侵染实验中，与同等发育阶段的Sinvalocho M.A.植物相比，HLP成株对叶锈病的抗性增强，这表明HLP突变可能赋予了对真菌的抗性增强。由于抗性增强与自发性HR损伤的存在相吻合，因此HLP植物防御反应的激活似乎与这一现象密切相关。突变株的最终株高和产量成分与母系没有差异，说明突变株没有产生显著影响农艺性能的有害多效效应。这些数据支持在抗病育种中直接使用突变。
A lesion-mimic mutant was obtained from a mutagenic treatment performed with ethyl methanesulfonate on the Argentine bread wheat (Triticum aestivum) cultivar Sinvalocho M.A. The HLP (hypersensitive-like phenotype) mutant exhibited tiny, discrete, white lesions in the absence of any pathogen, resembling the typical hypersensitive response (HR). The lesions only became evident once the fifth or sixth leaf emerged, and spread at random along the leaf blades and leaf sheaths of the developing plant, including tissues of the spike. Because the lesion-mimic mutant showed no lesions at the seedling stage, the phenotypes of both the mutant and its mother line were identical at this point. Histochemical studies showed that spontaneous hypersensitive-like lesions in the HLP mutant corresponded to cell death. In leaf-rust (Puccinia triticina) infection experiments performed at seedling and adult-plant stages, adult HLP plants showed enhanced resistance to leaf-rust attack compared with plants of Sinvalocho M.A. of comparable developmental stage, suggesting that the HLP mutation may confer increased resistance to the fungus. Because enhanced resistance coincided with the presence of spontaneous HR lesions, activation of HLP plant defence responses appeared to be tightly linked to this phenomenon. Final plant height and yield components in the lesion-mimic mutant did not differ from those of the mother line, indicating that the HLP mutation caused no detrimental pleiotropic effects that significantly affected agronomic performance. These data support the direct use of mutations in disease-resistance breeding.