AVRXA10 CONTAINS AN ACIDIC TRANSCRIPTIONAL ACTIVATION DOMAIN IN THE FUNCTIONALLY CONSERVED C-TERMINUS

Citation
Wg. Zhu et al., AVRXA10 CONTAINS AN ACIDIC TRANSCRIPTIONAL ACTIVATION DOMAIN IN THE FUNCTIONALLY CONSERVED C-TERMINUS, Molecular plant-microbe interactions, 11(8), 1998, pp. 824-832
Citations number
51
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Plant Sciences","Biothechnology & Applied Migrobiology",Biology
ISSN journal
0894-0282
Volume
11
Issue
8
Year of publication
1998
Pages
824 - 832
Database
ISI
SICI code
0894-0282(1998)11:8<824:ACAATA>2.0.ZU;2-F
Abstract
The avrXa10 gene of Xanthomonas oryzae pv, oryzae, the causal agent of bacterial blight of rice, is a member of the avrBs3 avirulence gene f amily and directs the elicitation of resistance in a gene-for-gene man ner on rice lines carrying the resistance gene Xa10. The carboxyl (C) terminus of AvrXa10 has a previously undescribed domain that is struct urally similar to the acidic activation domain of many eukaryotic tran scription factors in addition to three nuclear localization signal (NL S) sequences. Removal of the C-terminal 38 codons containing the putat ive activation domain, but retaining the NLS sequences, was concomitan t with the loss of avirulence activity. The C-terminal coding regions of avrBs3 and avrXa7 can be replaced by the corresponding region of av rXa10, and the genes retained specificity for the resistance genes Bs3 in pepper and Xa7 in rice, respectively. The avrBs3 and avrXa7 avirul ence activities of the hybrid genes were also lost upon removal of the terminal 38 codons, When fused to the coding sequence of the Ga14 DNA binding domain, AvrXa10 activated transcription in yeast and Arabidop sis thaliana. Removal of the carboxyl region severely reduced transcri ptional activation. AvrXa10 would have to be localized to the host cel l nucleus to function autonomously in transcriptional activation. Cons istent with this requirement, mutations in all three NLS sequences of avrXa10 caused a loss in avirulence activity, The findings demonstrate the requirement of the C terminus for AvrXa10 function and the potent ial for the members of this family of avirulence gene products to ente r the host nucleus and alter host transcription.