Os11g0208900

From RiceWiki
Jump to: navigation, search

Os05g0107700, named as xa5, is a recessive gene associated with resistance to rice bacterial leaf blight.

Annotated Information

Function

Xa3/Xa26 mediates resistance to bacterial blight, a disease caused by Xanthomonas oryzae pv. oryzae (Xoo), which is a significant agronomic problem in rice-growing regions.The rice disease resistance (R) gene Xa3/Xa26 (having also been named Xa3 and Xa26) against Xanthomonas oryzae pv. oryzae (Xoo), which causes bacterial blight disease, belongs to a multiple gene family clustered in chromosome 11 and is from an AA genome rice cultivar (Oryza sativa L.). This family encodes leucine-rich repeat (LRR) receptor kinasetype proteins. Asian-cultivated rice consists of two major subspecies, indica (O. sativa L. ssp. indica) and japonica (O. sativa L. ssp. japonica).

Expression

The indica plants carrying Xa3/Xa26 were highly susceptible in four-leaf stage, but become resistant or moderately resistant to these Xoo races at booting stage. The development-controlled Xa3/Xa26 activity is also associated with its expression level (Cao et al. 2007).

Evolution

The orthologs (alleles) of Xa3/Xa26, Xa3/Xa26-2, and Xa3/Xa26-3, from wild Oryza species O. officinalis (CC genome) and O. minuta (BBCC genome), respectively, were also R genes against Xoo. Xa3/Xa26-2 and Xa3/Xa26-3 conferred resistance to 16 of the 18 Xoo strains examined. Comparative sequence analysis of the Xa3/Xa26 families in the two wild Oryza species showed that Xa3/Xa26-3 appeared to have originated from the CC genome of O. minuta. The predicted proteins encoded by Xa3/Xa26, Xa3/Xa26-2, and Xa3/Xa26-3 share 91–99% sequence identity and 94–99% sequence similarity.

Knowledge Extension

Xa3/Xa26 was first identified in the indica rice cultivar Minghui 63 and named Xa26. Further study revealed that Xa3, an R gene conferring resistance against Xoo, and Xa26 are actually the same gene and then it was renamed Xa3/Xa26. Xa3/Xa26 has been an important resistance gene for both indica and japonica rice production in China for a long time.

Labs working on this gene

  • Department of Plant Breeding and Genetics, Cornell University, Ithaca, NY 14853, USA.

References

Cite error: <ref> tag defined in <references> has group attribute "" which does not appear in prior text.


Structured Information