Partial demethylation of oligogalacturonides by pectin methyl esterase 1 is required for eliciting defence responses in wild strawberry (Fragaria vesca)
Partial demethylation of oligogalacturonides by pectin methyl esterase 1 is required for eliciting defence responses in wild strawberry (Fragaria vesca)
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DOI：
10.1111/j.1365-313x.2007.03398.x
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发表时间：
2008-04-01
期刊：
影响因子：
7.2
通讯作者：
Valpuesta, Victoriano
中科院分区：
文献类型：
--
作者：
Osorio, Sonia;Castillejo, Cristina;Valpuesta, Victoriano
除了细胞壁作为抵抗病原体的物理屏障的作用之外，其一些成分，例如果胶衍生的寡聚半乳糖醛酸（OGA），是引发防御反应的必要组分。为了研究果胶的修饰如何改变防御反应，我们在野生草莓中表达了果实特异性草莓x ananassa果胶甲酯酶FaPE 1。转基因成熟果实的果胶不同于野生型的甲基酯化的程度和模式，以及果胶聚合物的平均大小。从转基因水果纯化的寡聚半乳糖醛酸苷相比，从野生型水果的寡聚半乳糖醛酸苷的酯化程度降低。这种减少的酯化是必要的，以引起草莓的防御反应。转基因F. vesca品系具有组成型激活的病原体防御反应，导致对坏死性真菌灰葡萄孢的较高抗性。进一步研究F. vesca和Nicotianabenthamiana叶片的结果表明，寡聚半乳糖醛酸的诱导能力比以前设想的更特异。
In addition to the role of the cell wall as a physical barrier against pathogens, some of its constituents, such as pectin-derived oligogalacturonides (OGA), are essential components for elicitation of defence responses. To investigate how modifications of pectin alter defence responses, we expressed the fruit-specific Fragaria x ananassa pectin methyl esterase FaPE1 in the wild strawberry Fragaria vesca. Pectin from transgenic ripe fruits differed from the wild-type with regard to the degree and pattern of methyl esterification, as well as the average size of pectin polymers. Purified oligogalacturonides from the transgenic fruits showed a reduced degree of esterification compared to oligogalacturonides from wild-type fruits. This reduced esterification is necessary to elicit defence responses in strawberry. The transgenic F. vesca lines had constitutively activated pathogen defence responses, resulting in higher resistance to the necrotropic fungus Botrytis cinerea. Further studies in F. vesca and Nicotiana benthamiana leaves showed that the elicitation capacity of the oligogalacturonides is more specific than previously envisaged.