molecular evolution of the rice blast resistance gene pi-ta in invasive weedy rice in the usa稻瘟病抗性基因的分子进化pi-ta入侵杂草稻在美国.pdfVIP

Molecular Evolution of the Rice Blast Resistance Gene Pi-ta in Invasive Weedy Rice in the USA 1,2 3 3 3 4 5 Seonghee Lee , Yulin Jia *, Melissa Jia , David R. Gealy , Kenneth M. Olsen , Ana L. Caicedo 1 Rice Research Extension Center, University of Arkansas, Stuttgart, Arkansas, United States of America, 2 The Samuel Roberts Noble Foundation, Ardmore, Oklahoma, United States of America, 3 Dale Bumpers National Rice Research Center, Agricultural Research Service, United States Department of Agriculture, Stuttgart, Arkansas, United States of America, 4 Department of Biology, Washington University, St. Louis, Missouri, United States of America, 5 Department of Biology, University of Massachusetts, Amherst, Massachusetts, United States of America Abstract The Pi-ta gene in rice has been effectively used to control rice blast disease caused by Magnaporthe oryzae worldwide. Despite a number of studies that reported the Pi-ta gene in domesticated rice and wild species, little is known about how the Pi-ta gene has evolved in US weedy rice, a major weed of rice. To investigate the genome organization of the Pi-ta gene in weedy rice and its relationship to gene flow between cultivated and weedy rice in the US, we analyzed nucleotide sequence variation at the Pi-ta gene and its surrounding 2 Mb region in 156 weedy, domesticated and wild rice relatives. We found that the region at and around the Pi-ta gene shows very low genetic diversity in US weedy rice. The patterns of molecular diversity in weeds are more similar to cultivated rice (indica and aus), which have never been cultivated in the US, rather than the wild rice species, Oryza rufipogon. In addition, the resistant Pi