Dissection of the factors affecting development-controlled and race-specific disease resistance conferred by leucine-rich repeat receptor kinase-type R genes in rice.
Development-controlled resistance and resistance specificity frequently restrict the application of a disease resistance (R) gene in crop breeding programs. Xa3/Xa26 and Xa21, encoding leucine-rich repeat (LRR)-kinase type plasma membrane proteins, mediate race-specific resistance to Xanthomonas oryzae pv. oryzae (Xoo), which causes bacterial blight, one of the most devastating rice diseases. Plants carrying Xa3/Xa26 and plants carrying Xa21 have different resistance spectra and the functions of the two R genes are regulated by developmental stage. Four chimeric genes encoding proteins consisting of different parts of XA3/XA26 and XA21 were constructed by domain swapping and transformed into a susceptible rice variety. The resistance spectra and development-regulated resistance of the transgenic plants carrying Xa3/Xa26, Xa21, or chimeric gene to different Xoo strains were analyzed in the same genetic background. The results suggest that the gradually increased expression of Xa3/Xa26 and Xa21 plays an important role in the progressively enhanced Xoo resistance during rice development. In addition, the LRR domains of XA3/XA26 and XA21 are important determinants of race-specific recognition during rice-Xoo interaction, but juxtamembrane regions of the two R proteins also appear to contribute to resistance specificity.
Zhao
Jing
J
National Key Laboratory of Crop Genetic Improvement, National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China.
Fu
Jing
J
Li
Xianghua
X
Xu
Caiguo
C
Wang
Shiping
S
D000595:Amino Acid Sequence; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D007113:Immunity, Innate / Q000235:genetics*; D000090263:Leucine-Rich Repeat Proteins; D008969:Molecular Sequence Data; D012275:Oryza / Q000235:genetics* / Q000254:growth & development* / Q000382:microbiology; D010935:Plant Diseases / Q000235:genetics / Q000276:immunology*; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D011506:Proteins / Q000235:genetics*; D013045:Species Specificity; D014974:Xanthomonas / Q000502:physiology
D000090263:Leucine-Rich Repeat Proteins; D010940:Plant Proteins; D011506:Proteins