School of Integrative Plant Science, Cornell University, Ithaca, New York 14853; email:
Annu Rev Phytopathol. 2016 Aug 4;54:229-52. doi: 10.1146/annurev-phyto-080615-100037. Epub 2016 Jan 1.
Many plants, both in nature and in agriculture, are resistant to multiple diseases. Although much of the plant innate immunity system provides highly specific resistance, there is emerging evidence to support the hypothesis that some components of plant defense are relatively nonspecific, providing multiple disease resistance (MDR). Understanding MDR is of fundamental and practical interest to plant biologists, pathologists, and breeders. This review takes stock of the available evidence related to the MDR hypothesis. Questions about MDR are considered primarily through the lens of forward genetics, starting at the organismal level and proceeding to the locus level and, finally, to the gene level. At the organismal level, MDR may be controlled by clusters of R genes that evolve under diversifying selection, by dispersed, pathogen-specific genes, and/or by individual genes providing MDR. Based on the few MDR loci that are well-understood, MDR is conditioned by diverse mechanisms at the locus and gene levels.
许多植物，无论是在自然界中还是在农业中，都对多种疾病具有抗性。虽然植物先天免疫系统的大部分提供了高度特异性的抗性，但有越来越多的证据支持这样一种假设，即植物防御的某些成分相对非特异性，提供了多种疾病抗性（MDR）。植物生物学家、病理学家和育种家对理解 MDR 具有基础和实际的兴趣。这篇综述评估了与 MDR 假说相关的现有证据。通过正向遗传学的角度考虑 MDR 问题，从生物体水平开始，然后到基因座水平，最后到基因水平。在生物体水平上，MDR 可能受进化受到多样化选择的 R 基因簇、分散的、针对病原体的基因以及/或提供 MDR 的单个基因控制。基于少数几个了解得很好的 MDR 基因座，MDR 是由基因座和基因水平上的多种机制决定的。
