Plants are in a constant evolutionary arms race with their pathogens. At the molecular level, the plant nucleotide-binding leucine-rich repeat receptors (NLRs) family has coevolved with rapidly evolving pathogen effectors. While many NLRs utilize variable leucine-rich repeats (LRRs) to detect effectors, some have gained integrated domains (IDs) that may be involved in receptor activation or downstream signaling. The major objectives of this project were to identify NLR genes in wheat (Triticum aestivum L.) and assess IDs associated with immune signaling (e.g., kinase and transcription factor domains). We identified 2,151 NLR-like genes in wheat, of which 1,298 formed 547 gene clusters. Among the non-toll/interleukin-1 receptor NLR (non-TNL)-like genes, 1,552 encode LRRs, 802 are coiled-coil (CC) domain-encoding (CC-NBS-LRR or CNL) genes, and three encode resistance to powdery mildew 8 (RPW8) domains (RPW8-NBS-LRR or RNL). The expansion of the NLR gene family in wheat is attributable to its origin by recent polyploidy events. Gene clusters were likely formed by tandem duplications, and wheat NLR phylogenetic relationships were similar to those in barley and Aegilops. We also identified wheat NLR-ID fusion proteins as candidates for NLR functional diversification, often as kinase and transcription factor domains. Comparative analyses of the IDs revealed evolutionary conservation of more than 80% amino acid sequence similarity. Homology assessment indicates that these domains originated as functional non-NLR-encoding genes that were incorporated into NLR-encoding genes through duplication events. We also found that many of the NLR-ID genes encode alternative transcripts that include or exclude IDs, a phenomenon that seems to be conserved among species. To verify this, we have analyzed the alternative transcripts that include or exclude an ID of an NLR-ID from another monocotyledon species, rice (Oryza sativa). This indicates that plants employ alternative splicing to regulate IDs, possibly using them as baits, decoys, and functional signaling components. Genomic and expression data support the hypothesis that wheat uses alternative splicing to include and exclude IDs from NLR proteins.

植物与其病原体处于持续的进化军备竞赛中。在分子水平上，植物核苷酸结合的富含亮氨酸的重复受体（NLR）家族与迅速发展的病原体效应子共同进化。尽管许多NLR利用可变富亮氨酸重复序列（LRR）来检测效应子，但有些已经获得了可能参与受体激活或下游信号传导的整合域（ID）。该项目的主要目标是鉴定小麦中的NLR基因（普通小麦L.）并评估与免疫信号相关的ID（例如，激酶和转录因子结构域）。我们在小麦中鉴定了2,151个NLR样基因，其中1,298个形成了547个基因簇。在非收费/白介素1受体NLR（非TNL）样基因中，有1,552个编码LRR，802个是卷曲螺旋（CC）域编码（CC-NBS-LRR或CNL）基因，三个编码抗性白粉病8（RPW8）域（RPW8-NBS-LRR或RNL）。小麦中NLR基因家族的扩展归因于最近的多倍体事件。基因簇很可能是由串联重复形成的，小麦NLR的系统发生关系与大麦和大麦相似。埃吉洛普斯。我们还确定了小麦NLR-ID融合蛋白可作为NLR功能多样化的候选蛋白，通常作为激酶和转录因子结构域。对ID的比较分析显示，进化保守性超过80％的氨基酸序列相似性。同源性评估表明，这些结构域起源于功能性非NLR编码基因，这些基因通过复制事件整合到NLR编码基因中。我们还发现，许多NLR-ID基因编码包含或排除ID的替代转录本，这种现象在物种间似乎是保守的。为了验证这一点，我们已经分析了其他单子叶植物水稻（包括水稻）。这表明植物采用替代剪接来调节ID，可能将它们用作诱饵，诱饵和功能性信号传导成分。基因组和表达数据支持以下假设：小麦使用替代剪接从NLR蛋白中包括和排除ID。