Maize Leaf Epiphytic Bacteria Diversity Patterns Are Genetically Correlated with Resistance to Fungal Pathogen Infection
Maize Leaf Epiphytic Bacteria Diversity Patterns Are Genetically Correlated with Resistance to Fungal Pathogen Infection
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DOI：
10.1094/mpmi-23-4-0473
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发表时间：
2010-04-01
影响因子：
3.5
通讯作者：
Stapleton, Ann E.
中科院分区：
文献类型：
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作者：
Balint-Kurti, Peter;Simmons, Susan J.;Stapleton, Ann E.
植物叶子上有一组特定的微生物附生物。通过测定玉米重组自交系（RI）作图群体中附生细菌核糖体DNA多样性，研究了植物遗传和太阳UV-B辐射对叶际多样性的影响。确定了几个对细菌多样性有显著影响的染色体数量性状位点（QTL），其中一些仅在UV-B辐射存在下有影响，另一些在有和没有UV-B的情况下都有影响。将具有等位基因特异性效应的候选基因与细菌多样性染色体区域对齐。谷氨酸脱羧酶候选基因位于UV-B特异性染色体位点，并在两个RI线与对比细菌多样性表型之间的比较中，高细菌多样性与高水平的谷氨酸脱羧酶活性，γ-氨基丁酸（GABA）途径的一个组成部分。细菌多样性位点表现出显着的重叠位点与南方叶枯病（SLB）的敏感性在外地。SLB抗性近交基因型具有较少的β细菌多样性，抗生素治疗的近交增加了这种多样性。这些结果表明，GABA途径与叶际细菌多样性在遗传上相关。此外，低细菌多样性和真菌枯萎病抗性之间的QTL的共定位，并在β多样性的增加，在杀虫剂处理的叶片表明，由一组特定的抑制细菌的叶栖息地的占领可能会限制叶际细菌的变异性，并增加对真菌感染的抗性。
Plant leaves host a specific set of microbial epiphytes. Plant genetic and solar UV-B radiation effects on the diversity of the phyllosphere were examined by measuring epiphytic bacterial ribosomal DNA diversity in a maize recombinant inbred (RI) mapping population. Several chromosomal quantitative trait loci (QTL) with significant effects on bacterial diversity, were identified, some of which had effects only in the presence of UV-B radiation and others that had effects both with and without UV-B. Candidate genes with allele-specific effects were snapped to the bacterial diversity chromosomal regions. A glutamate decarboxylase candidate gene was located at a UV-B-specific chromosomal locus, and in a comparison between two RI lines with contrasting bacterial diversity phenotypes, high bacterial diversity was associated with high levels of glutamate decarboxylase enzyme activity, a component of the gamma-aminobutyric acid (GABA) pathway. The bacterial diversity loci exhibited a significant overlap with loci connected with Southern leaf blight (SLB) susceptibility in the field. A SLB-resistant inbred genotype had less beta bacterial diversity, and antibiotic treatment of inbreds increased this diversity. These results suggest that the GABA pathway is genetically associated with phyllosphere bacterial diversity. Furthermore, the colocalization of QTL between low bacterial diversity and fungal blight-resistance and the increase in beta diversity in antibiotic-treated leaves suggest that occupation of leaf habitats by a particular set of suppressive bacteria may restrict phyllosphere bacterial variability and increase resistance to fungal infection.