When QTLs meet genomics: genomic analyses of rice monocupins, candidate genes for quantitative resistance to rice blast
2007
Carrillo, G., International Rice Research Inst., DAPO Box 7777, Metro Manila (Philippines) | Goodwin, P., Univ. of Guelph, Guelph, N1G 2W1 (Canada) | Reveche, Ma.Y., (International Rice Research Inst., DAPO Box 7777, Metro Manila (Philippines) | Leach, J.E., Colorado State Univ., Fort Collins, 80523-1177 (USA) | Leung, H. | Vera Cruz, C.M., (International Rice Research Inst., DAPO Box 7777, Metro Manila (Philippines)
Converging evidence from wheat, barley and peanut as well as genetic mapping studies suggest an important role of monocupins in resistance to fungal pathogens. Monocupins are members of the cupin superfamily of proteins with members involved in developmental and defense response pathways. In rice, two monocupins mapped to chromosome 3 and 8 oxalate oxidase-like proteins, respectively and are associated with QTLs for resistance to rice blast. The authors present a complete overview of rice monocupins, including gene structure, conserved motifs, chromosome locations, and phylogeny. The author's analysis indicates that oxalate oxidases form a unique subclass composed of four members - LOC-Os03g 48750 (OsOxo1), LOC-Os03g 48760 (OsOx02), LOC-Os03g48770 (OsOx03), and LOC-Os03g 48780 (OsOx04) while there are 12 oxalate oxidase-like proteins in chromosome 8. EST analyses for each gene indicate that not all are expressed in the rice genome. Expression analysis of the four oxalate oxidases using resistant and susceptible advance backcross lines of Vandana x Moroberekan showed that only Os Oxo4 is expressed during rice-Magnaporthe grisea interaction. Sequence analysis of the 1000 bp upstream region of each gene reveals variation in class and copy number of cis-elements involved in defense response. Through in silico approaches, the authors also identified other members of the monocupin family, such as the nectarin 1 proteins, with putative roles in defense response based on homology with reported monocupins involved in fungal resistance.
显示更多 [+] 显示较少 [-]