Xanthomonas oryzae pathovar oryzae(Xoo)uses transcription activator-like effectors(TALEs)to cause bacterial blight(BB)in rice.In turn,rice has evolved several mechanisms to resist BB by targeting TALEs.One mechanism i...Xanthomonas oryzae pathovar oryzae(Xoo)uses transcription activator-like effectors(TALEs)to cause bacterial blight(BB)in rice.In turn,rice has evolved several mechanisms to resist BB by targeting TALEs.One mechanism involves the nucleotide-binding leucine-rich repeat(NLR)resistance gene Xa1 and TALEs.Reciprocally,Xoo has evolved TALE variants,C-terminally truncated versions(interfering TALEs or iTALEs),to overcome Xa1 resistance.However,it remains unknown to what extent the two co-adaptive mechanisms mediate Xoo–rice interactions.In this study,we cloned and characterized five additional Xa1 allelic R genes,Xa2,Xa31(t),Xa14,CGS-Xo111,and Xa45(t)from a collection of rice accessions.Sequence analysis revealed that Xa2 and Xa31(t)from different rice cultivars are identical.These genes and their predicted proteins were found to be highly conserved,forming a group of Xa1 alleles.The XA1 alleles could be distinguished by the number of C-terminal tandemrepeats consisting of 93 amino acid residues and ranged from four in XA14 to seven in XA45(t).Xa1 allelic genes were identified in the 3000 rice genomes surveyed.On the other hand,iTALEs could suppress the resistance mediated by Xa1 allelic R genes,and iTALE genes were prevalent(95%)in Asian,but not in African Xoo strains.Our findings demonstrate the prominence of a defense mechanism in which rice depends on Xa1 alleles and a counteracting mechanismin which Xoo relies on iTALEs for BB.展开更多
基金supported by the National Natural Science Foundation of China(31830072 to G.C.)the United States Department of Agriculture National Institute of Agriculture and Food(2017-67013-26521 to B.Y.)+1 种基金the Young Elite Scientist Sponsorship of the China Association for Science and Technology(2017QNRC001 to Z.J.)the Chinese National Transgenic Major Program(2016ZX08001-002 to G.C.).
文摘Xanthomonas oryzae pathovar oryzae(Xoo)uses transcription activator-like effectors(TALEs)to cause bacterial blight(BB)in rice.In turn,rice has evolved several mechanisms to resist BB by targeting TALEs.One mechanism involves the nucleotide-binding leucine-rich repeat(NLR)resistance gene Xa1 and TALEs.Reciprocally,Xoo has evolved TALE variants,C-terminally truncated versions(interfering TALEs or iTALEs),to overcome Xa1 resistance.However,it remains unknown to what extent the two co-adaptive mechanisms mediate Xoo–rice interactions.In this study,we cloned and characterized five additional Xa1 allelic R genes,Xa2,Xa31(t),Xa14,CGS-Xo111,and Xa45(t)from a collection of rice accessions.Sequence analysis revealed that Xa2 and Xa31(t)from different rice cultivars are identical.These genes and their predicted proteins were found to be highly conserved,forming a group of Xa1 alleles.The XA1 alleles could be distinguished by the number of C-terminal tandemrepeats consisting of 93 amino acid residues and ranged from four in XA14 to seven in XA45(t).Xa1 allelic genes were identified in the 3000 rice genomes surveyed.On the other hand,iTALEs could suppress the resistance mediated by Xa1 allelic R genes,and iTALE genes were prevalent(95%)in Asian,but not in African Xoo strains.Our findings demonstrate the prominence of a defense mechanism in which rice depends on Xa1 alleles and a counteracting mechanismin which Xoo relies on iTALEs for BB.
