PNAS|拟南芥细胞壁成分决定抗病性特异性和适应性
植物细胞壁是一种复杂的结构，在抗病反应中起着重要的作用。我们通过测定一组拟南芥细胞壁突变体(Cwm)对不同寄生方式的病原菌(维管束细菌、坏死性真菌和生物营养型卵菌)的敏感性来测试植物细胞壁对免疫的特异性贡献。
值得注意的是，与野生型植物相比，大多数Cwm细胞壁突变体(29/34；85.3%)对至少一种病原菌的抗性反应发生了变化，说明了壁成分在决定抗病表型方面的相关性。
我们发现，Cwm植株对坏死病和维管束病原菌的抗性增强，对Cwm适合性性状(如生物量和种子产量)产生了负面影响。
Cwm植物的抗性增强不仅仅是由典型的免疫途径介导的，比如那些受植物激素或微生物相关分子模式调控的免疫途径，这些途径在Cwm测试中没有被解除调控。
从Cwm植物中分离出的富含果胶的壁组分在野生型植物中触发了免疫反应，这表明壁介导的防御途径可能有助于Cwm的抗性。
图 与野生型植物相比，拟南芥细胞壁突变体显示出其抗病性表型的改变
Cwm植物的细胞壁表现出高度多样性的成分变化，正如检测特定壁碳水化合物部分的糖类图谱所揭示的那样。
糖类图谱数据的数学分析确定了Cwm植株比壁碳水化合物含量与抗病表型之间的相关性。
这些数据支持了植物壁组分在植物免疫应答调节和平衡抗病/发育权衡中的相关和特定功能。
Plant cell walls are complex structures subject to dynamic remodeling in response to developmental and environmental cues and play essential functions in disease resistance responses. We tested the specific contribution of plant cell walls to immunity by determining the susceptibility of a set of Arabidopsis cell wall mutants (cwm) to pathogens with different parasitic styles: a vascular bacterium, a necrotrophic fungus, and a biotrophic oomycete. Remarkably, most cwm mutants tested (29/34; 85.3%) showed alterations in their resistance responses to at least one of these pathogens in comparison to wild-type plants, illustrating the relevance of wall composition in determining disease-resistance phenotypes. We found that the enhanced resistance of cwm plants to the necrotrophic and vascular pathogens negatively impacted cwm fitness traits, such as biomass and seed yield. Enhanced resistance of cwm plants is not only mediated by canonical immune pathways, like those modulated by phytohormones or microbe-associated molecular patterns, which are not deregulated in the cwm tested. Pectin-enriched wall fractions isolated from cwm plants triggered immune responses in wild-type plants, suggesting that wall-mediated defensive pathways might contribute to cwm resistance. Cell walls of cwm plants show a high diversity of composition alterations as revealed by glycome profiling that detect specific wall carbohydrate moieties. Mathematical analysis of glycome profiling data identified correlations between the amounts of specific wall carbohydrate moieties and disease resistance phenotypes of cwm plants. These data support the relevant and specific function of plant wall composition in plant immune response modulation and in balancing disease resistance/development trade-offs.
https://www.pnas.org/content/pnas/118/5/e2010243118.full.pdf
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