CAJ | 학술논문

白叶枯病菌与水稻间的互作符合基因对基因模式,不同小种中存在特异的avrBs3/pthA家族基因.对中国水稻白叶枯病菌小种C8菌株基因组DNA进行BamHⅠ酶切和Southern杂交,发现了其特有的约6.0 kb大小、含avrBs3/pthA家族基因的信号条带.经文库筛选、Southern杂交和限制性酶切分析,获得了C8小种avr/pthC8a基因.将该基因导入菲律宾小种6 的代表菌株PXO99~A中,发现avr/pthC8a可使PXO99~A丧失对水稻品种Asominori(携有成株期抗性基因Xa17)的毒性,暗示avr/pthC8a可能是与Xa17相应的无毒基因.序列分析发现,avr/pthC8a基因大小为3816 bp,编码1272个氨基酸,由102 bp编码的34个氨基酸重复单元在基因内的重复数为20.5个,其3'端的BamHⅠ酶切位点由GGATCC突变为AGATCC,其他特征均与avrBs3/pthA家族的成员相似,即C端存在1个亮氨酸拉链、3个核定位信号和1个酸性转录激活域.avr/pthC8a基因3'端的BamHⅠ酶切位点发生突变在avrBs3/pthA家族基因中鲜有报道.中国C8小种avr/pthC8a基因的发掘,为进一步了解水稻黄单胞菌毒性变异以及avrBs3/pthA家族基因的进化提供了理论依据.
백협고병균여수도간적호작부합기인대기인모식,불동소충중존재특이적avrBs3/pthA가족기인.대중국수도백협고병균소충C8균주기인조DNA진행BamHⅠ매절화Southern잡교,발현료기특유적약6.0 kb대소、함avrBs3/pthA가족기인적신호조대.경문고사선、Southern잡교화한제성매절분석,획득료C8소충avr/pthC8a기인.장해기인도입비률빈소충6 적대표균주PXO99~A중,발현avr/pthC8a가사PXO99~A상실대수도품충Asominori(휴유성주기항성기인Xa17)적독성,암시avr/pthC8a가능시여Xa17상응적무독기인.서렬분석발현,avr/pthC8a기인대소위3816 bp,편마1272개안기산,유102 bp편마적34개안기산중복단원재기인내적중복수위20.5개,기3'단적BamHⅠ매절위점유GGATCC돌변위AGATCC,기타특정균여avrBs3/pthA가족적성원상사,즉C단존재1개량안산랍련、3개핵정위신호화1개산성전록격활역.avr/pthC8a기인3'단적BamHⅠ매절위점발생돌변재avrBs3/pthA가족기인중선유보도.중국C8소충avr/pthC8a기인적발굴,위진일보료해수도황단포균독성변이이급avrBs3/pthA가족기인적진화제공료이론의거.
The interaction between Xanthomonas oryzae pv. oryzae (Xoo) and rice follows gene-for-gene model. A 6.0 kb particular fragment was identified from a Chinese race C8 strain of Xoo, through screening its genomic library by Southern blot with a highly conserved EcoRⅠ-BamHⅠ fragment of the avrBs3/pthA family as probe. This specific DNA contained an avirulence gene, namely avr/pthC8a, which transmitted the Philippine strain PXO99~A from compatible into incompatible interactions with rice Asominori carrying R gene Xa17, suggesting that avr/pthC8a is possibly corresponding for Xa17 specificity. Sequence analysis showed that avr/pthC8a, 3819 bp in size, is a avrBs3/pthA family member, and the repeat number of the 102 bp repeat unit is 20.5. The structure of the gene is almost as same as those of the avrBs3/pthA family genes at 5'- and 3'-terminals. The putative protein has a lucine zipper, three nucleotide location signals and an acid transcriptional activation domain at C-terminal. The novel is that the BamHⅠ site at 3'-terminal of the gene is mutagenesis from GGATCC into AGATCC, which has not been reported so far. Thus, identification of avr/pthC8a of Chinese race C8 provides a fundamental understanding of virulence differentiation among different races of Xoo and coevolution of avrBs3/pthA genes with rice.