植物细胞质内一类具有核苷酸结合位点NBS (nucleotide binding site) 和富亮氨酸重复LRR (leucin-rich repeat) 结构域的抗病蛋白决定了植物免疫的特异性。编码NBS-LRR的抗病基因具有适合度代价，在没有病原侵染的情况下过量表达对植物自身是有害的。因此，植物通过多种方式控制NBS-LRR抗病基因的表达。在双子叶植物中，miRNA靶向大量NBS-LRR基因进而下调其表达。然而，十字花科植物中靶向NBS-LRR的miRNA是非常少的。本项目拟以十字花科芸薹属植物为研究对象，深入研究抗病基因的进化与其miRNA调控减少的机制，并分析表观修饰对NBS-LRR的调控作用。本项目将进一步通过实验进化生物学的手段，评价miRNA对抗病基因适合度代价的平衡作用，探索通过miRNA控制抗病基因的代价，开发抗病且产量稳定作物的可能性。

Plant cytoplasmic proteins containing nucleotide-binding site and leucine-rich repeat domains (NBS-LRRs) detect polymorphic, strain-specific pathogen effectors. High expression of plant nucleotide binding site leucine-rich repeat (NBS-LRR) defense genes is often lethal to plant cells, a phenotype perhaps associated with fitness costs. As negative transcriptional regulators, diverse miRNAs target NBS-LRRs in eudicots. However, there is few miRNAs targeting NBS-LRRs in Brassica. Thus, we will explore the evolution history of NBS-LRRs and the mechanism of loss of miRNAs in Brassica, together with other epigenetic regulation of NBS-LRRs. Furthermore, We will evaluate the control of miRNA to the fitness cost of NBS-LRRs and the possibility applying miRNAs to develop crops with resistance and stable production.