Surana Priyanka, Xu Ruo, Fuerst Gregory, Chapman Antony V E, Nettleton Dan, Wise Roger P
Interdepartmental Bioinformatics and Computational Biology Program, Iowa State University, Ames, Iowa 50011.
Department of Plant Pathology and Microbiology, Iowa State University, Ames, Iowa 50011.
G3 (Bethesda). 2017 Oct 5;7(10):3317-3329. doi: 10.1534/g3.117.300125.
Powdery mildew pathogens colonize over 9500 plant species, causing critical yield loss. The Ascomycete fungus, f. sp. (), causes powdery mildew disease in barley ( L.). Successful infection begins with penetration of host epidermal cells, culminating in haustorial feeding structures, facilitating delivery of fungal effectors to the plant and exchange of nutrients from host to pathogen. We used expression Quantitative Trait Locus (eQTL) analysis to dissect the temporal control of immunity-associated gene expression in a doubled haploid barley population challenged with Two highly significant regions possessing eQTL were identified near the telomeric ends of chromosomes (Chr) 2HL and 1HS. Within these regions reside diverse resistance loci derived from barley landrace ( and cv. Algerian (, which associate with the altered expression of 961 and 3296 genes during fungal penetration of the host and haustorial development, respectively. Regulatory control of transcript levels for 299 of the 961 genes is reprioritized from on 2HL to on 1HS as infection progresses, with 292 of the 299 alternating the allele responsible for higher expression, including Adaptin Protein-2 subunit μ AP2M and Vesicle Associated Membrane Protein VAMP72 subfamily members VAMP721/722. AP2M mediates effector-triggered immunity (ETI) via endocytosis of plasma membrane receptor components. VAMP721/722 and SNAP33 form a Soluble N-ethylmaleimide-sensitive factor Attachment Protein REceptor (SNARE) complex with SYP121 (PEN1), which is engaged in pathogen associated molecular pattern (PAMP)-triggered immunity via exocytosis. We postulate that genes regulated by alternate chromosomal positions are repurposed as part of a conserved immune complex to respond to different pathogen attack scenarios.
白粉病病原体可侵染9500多种植物，导致严重的产量损失。子囊菌真菌 ，f. sp. （），可引起大麦（L.）的白粉病。成功的感染始于宿主表皮细胞的穿透，最终形成吸器取食结构，促进真菌效应子向植物的传递以及营养物质从宿主到病原体的交换。我们使用表达定量性状位点（eQTL）分析来剖析在受到 挑战的双单倍体大麦群体中免疫相关基因表达的时间控制。在染色体（Chr）2HL和1HS的端粒末端附近鉴定出两个具有eQTL的高度显著区域。在这些区域内存在源自大麦地方品种（ 和 ）以及阿尔及利亚品种（）的多种抗性位点，它们分别与宿主真菌穿透和吸器发育过程中961个和3296个基因的表达改变相关。随着感染的进展，961个基因中的299个转录本水平的调控控制从2HL上的 重新分配到1HS上的 ，其中299个中的292个交替了负责更高表达的等位基因，包括衔接蛋白-2亚基μ（AP2M）和囊泡相关膜蛋白VAMP72亚家族成员VAMP721/722。AP2M通过质膜受体成分的内吞作用介导效应子触发的免疫（ETI）。VAMP721/722和SNAP33与SYP121（PEN1）形成可溶性N-乙基马来酰亚胺敏感因子附着蛋白受体（SNARE）复合体，该复合体通过胞吐作用参与病原体相关分子模式（PAMP）触发的免疫。我们推测，由交替染色体位置调控的基因被重新利用，作为保守免疫复合体的一部分，以应对不同的病原体攻击情况。
