Nagy Ervin D, Lee Tso-Ching, Ramakrishna Wusirika, Xu Zijun, Klein Patricia E, SanMiguel Phillip, Cheng Chiu-Ping, Li Jingling, Devos Katrien M, Schertz Keith, Dunkle Larry, Bennetzen Jeffrey L
Department of Genetics, University of Georgia, Athens, GA, 30602, USA.
Theor Appl Genet. 2007 Apr;114(6):961-70. doi: 10.1007/s00122-006-0481-1. Epub 2007 Mar 14.
Milo disease in sorghum is caused by isolates of the soil-borne fungus Periconia circinata that produce PC-toxin. Susceptibility to milo disease is conditioned by a single, semi-dominant gene, termed Pc. The susceptible allele (Pc) converts to a resistant form (pc) spontaneously at a gametic frequency of 10(-3) to 10(-4). A high-density genetic map was constructed around the Pc locus using DNA markers, allowing the Pc gene to be delimited to a 0.9 cM region on the short arm of sorghum chromosome 9. Physically, the Pc-region was covered by a single BAC clone. Sequence analysis of this BAC revealed twelve gene candidates. Several of the predicted genes in the region are homologous to disease resistance loci, including one NBS-LRR resistance gene analogue that is present in multiple tandem copies. Analysis of pc isolines derived from Pc/Pc sorghum suggests that one or more members of this NBS-LRR gene family are the Pc genes that condition susceptibility.
高粱的米洛病由土壤传播的真菌环形巨座壳（Periconia circinata）的分离株引起，这些分离株会产生PC毒素。对米洛病的易感性由一个单基因、半显性基因Pc决定。易感等位基因（Pc）以10^(-3)至10^(-4)的配子频率自发转化为抗性形式（pc）。利用DNA标记在Pc基因座周围构建了高密度遗传图谱，将Pc基因定位于高粱第9号染色体短臂上一个0.9厘摩的区域。从物理角度看，Pc区域由一个单一的BAC克隆覆盖。对该BAC的序列分析揭示了12个候选基因。该区域的几个预测基因与抗病基因座同源，包括一个以多个串联拷贝形式存在的NBS-LRR抗性基因类似物。对源自Pc/Pc高粱的pc同型系的分析表明，这个NBS-LRR基因家族的一个或多个成员是决定易感性的Pc基因。
