AvrXa3: A novel member of avrBs3 gene family from Xanthomonas oryzae pv. oryzae has a dual function

作     者：LI Ping*, LONG Juying, HUANG Yingchun, ZHANG Yan and WANG Jinsheng**(Department of Plant Pathology, Nanjing Agricultural University, Key Laboratory of Monitoring and Management of Plant Disease and Insects, Ministry of Agriculture, Nanjing 210095, China) 

作者机构：Department of Plant Pathology Nanjing Agricultural University Key Laboratory of Monitoring and Management of Plant Disease and Insects Ministry of Agriculture Nanjing 210095 China 

出 版 物：《Progress in Natural Science:Materials International》 (自然科学进展·国际材料(英文))

年 卷 期：2004年第9期

页      面：30-36页

学科分类：0710[理学-生物学] 07[理学] 071007[理学-遗传学] 

基　　金：theNationalNaturalScienceFoundationofChina(GrantNo.30230240)andtheMajarStateBasicResearchDevelopmentProgramofChina(GrantNo.G200016201) 

主　　题：rice Xanthomonas oryzae pv. oryzae avrXa3 avrBs3 ( avr/pth ) family functional domains. 

摘      要：Two positive clones pUAV45 and pUAV47 were identified from the cDNA library of JxoⅢ, a race 3 strain of Xanthomonas oryzae pv. oryzae Dye (Xoo) in Japanese system, using Tn5 based technology. pUAV45 clone contained a 25.4 kb Xoo genomic DNA insert. Southern blot analysis with avrXa 10 as the probe showed that DNA insert in pUAV45 shares homology with avrX 10. Furthermore within the Xoo insert, a smaller 5.7 kb Kpn I fragment (pUAV5k) was identified through hybridization with avrXa 10. The transformation of pUAV45 and pUAV5k into the strain Pxo99 (race 6 in Philippine system) led to the decrease of Pxo99 pathogenicity on rice cultivar Wase Aikoku 3 ( Xa 3) and the increase of the pathogen pathogenicity on Cas209 ( Xa 10). The result of sequence analysis showed that there is a 2598 bp open reading frame (ORF) within the 5.7 kb Kpn 1 fragment (pUAV5k). The ORF shared high identity (97%) with avrXa 10. The deduced sequence of the ORF contained 8.5 tandem repeat units of 34 amino acids, one leucine zipper (LZ), three nuclear localization signal (NLS) motifs, and an acidic activation transcriptional domain (AAD) at C terminus. We named this ORF avrXa 3 and it is classified as a new member of avrBs 3 ( avr/pth ) family with the dual function determined by alternations of avirulence and aggressiveness on rice cultivars carrying different ‘ R ’ genes.