Transcription activator-like effector （TALE） nucleases （TALENs） are increasingly used as a powerful tool for genome edit- ing in a variety of organisms. We have previously cloned the TALE-coding gene avrXa23 from ...Transcription activator-like effector （TALE） nucleases （TALENs） are increasingly used as a powerful tool for genome edit- ing in a variety of organisms. We have previously cloned the TALE-coding gene avrXa23 from Xanthomonas oryzae pv. oryzae and developed an AvrXa23-based assembly system for designer TALEs or TALENs. Here, we exploit TALENs to induce mutagenesis of the rice ethylene response factor （ERF） transcription factor OsERF922 for testing the gene-editing efficiency of AvrXa23-based TALENs system. A pair of TALENs （T-KJ9/KJ 10） was assembled and their nuclease activities were first confirmed in rice protoplast transient assay. The TALENs-expressing construct pT-KJ9/KJ10 was then used for rice transformation. We observed targeting somatic mutagenesis frequency of 15.0% in positive transgenic rice calli and obtained two mutant plants with nucleotide deletion or insertion at the designer target region. Our work demonstrates that the AvrXa23-based TALENs system can be used for site-specific genome editing in rice.展开更多
The majority of plant disease resistance （R） genes encode proteins that share common structural features. However, the transcription activator-like effector （TALE）-associated executor type R genes show no consider...The majority of plant disease resistance （R） genes encode proteins that share common structural features. However, the transcription activator-like effector （TALE）-associated executor type R genes show no considerable sequence homology to any known R genes. We adopted a map-based cloning approach and TALE-based technology to isolate and characterize Xa23, a new executor R gene derived from wild rice （Oryza rufipogon） that confers an extremely broad spectrum of resistance to bacterial blight caused by Xanthomonas oryzae pv. oryzae （Xoo）. Xa23 encodes a 113 amino acid protein that shares 50% identity with the known executor R protein XA10. The predicted transmembrane helices in XA23 also overlap with those of XA10. Unlike XalO, however, Xa23 transcription is specifically activated by AvrXa23, a TALE present in all examined Xoo field isolates. Moreover, the susceptible xa23 allele has an identical open reading frame of Xa23 but differs in promoter region by lacking the TALE binding element （EBE） for AvrXa23. XA23 can trigger a strong hypersensitive response in rice, tobacco, and tomato. Our results provide the first evidence that plant genomes have an executor R gene family of which members execute their function and spectrum of disease resistance by recognizing the cognate TALEs in the pathogen.展开更多
基金supported by the grant from the Major Science and Technology Project to Create New Crop Cultivars Using Gene Transfer Technology of China (2014ZX0801001B)the National Natural Science Foundation of China (31171812)
文摘Transcription activator-like effector （TALE） nucleases （TALENs） are increasingly used as a powerful tool for genome edit- ing in a variety of organisms. We have previously cloned the TALE-coding gene avrXa23 from Xanthomonas oryzae pv. oryzae and developed an AvrXa23-based assembly system for designer TALEs or TALENs. Here, we exploit TALENs to induce mutagenesis of the rice ethylene response factor （ERF） transcription factor OsERF922 for testing the gene-editing efficiency of AvrXa23-based TALENs system. A pair of TALENs （T-KJ9/KJ 10） was assembled and their nuclease activities were first confirmed in rice protoplast transient assay. The TALENs-expressing construct pT-KJ9/KJ10 was then used for rice transformation. We observed targeting somatic mutagenesis frequency of 15.0% in positive transgenic rice calli and obtained two mutant plants with nucleotide deletion or insertion at the designer target region. Our work demonstrates that the AvrXa23-based TALENs system can be used for site-specific genome editing in rice.
文摘The majority of plant disease resistance （R） genes encode proteins that share common structural features. However, the transcription activator-like effector （TALE）-associated executor type R genes show no considerable sequence homology to any known R genes. We adopted a map-based cloning approach and TALE-based technology to isolate and characterize Xa23, a new executor R gene derived from wild rice （Oryza rufipogon） that confers an extremely broad spectrum of resistance to bacterial blight caused by Xanthomonas oryzae pv. oryzae （Xoo）. Xa23 encodes a 113 amino acid protein that shares 50% identity with the known executor R protein XA10. The predicted transmembrane helices in XA23 also overlap with those of XA10. Unlike XalO, however, Xa23 transcription is specifically activated by AvrXa23, a TALE present in all examined Xoo field isolates. Moreover, the susceptible xa23 allele has an identical open reading frame of Xa23 but differs in promoter region by lacking the TALE binding element （EBE） for AvrXa23. XA23 can trigger a strong hypersensitive response in rice, tobacco, and tomato. Our results provide the first evidence that plant genomes have an executor R gene family of which members execute their function and spectrum of disease resistance by recognizing the cognate TALEs in the pathogen.
