水稻白叶枯病菌无毒新基因的克隆和序列分析

从菲律宾水稻白叶枯病菌9a生理小种的代表菌株PX0339中克隆到一个新的无毒基因，全长2118bp，编码705个氨基酸，分子质量和等电点分别约为74．7ku和6．585．NCBI网站BLAST表明，该基因属于avrBs3基因家族，命名为arp3．与所有avrBs3同源基因的Alignment分析发现，arp3的5’端缺少了两个长度分别是144bp和45bp的片断，但在水稻白叶枯病菌中，arp3基因的5’端的特征很普遍．全长的arp3基因中间区域是一个特异的只有5．5次102bp的重复区，是已克隆的avrBs3基因家族中重复次数最少的一个，C-端有3个核定位信号NLSs和1个酸性转录激活域AAD．

Cloning and Sequencing of a Novel Avirulent Gene from Xanthomonas oryzae pv. Oryzae

A novel avirulent gene was cloned from Xanthomonas oryzae pv.oryzae PXO339 strains,which is the standard representative strain for race 9a in the Philippines,The full-length gene spans 2 118 bp and encodes a protein of 705 amino acids.Its molecular weight and isolectric point are 74.7 ku and 6.585,respectively.BLAST search in NCBI indicated that the gene belongs to avrBs3 gene family,and designated as arp3.Alignment Arp3 with others AvrBs3-like proteins uncovered that the 5' terminal of arp3 lacks of two segments,whose sizes are 144 and 45 bp,respectively.The 5' character of arp3 is common in all Xoo strain genomic DNA.The central region of the arp3 contains 5.5 copies of 102 bp repeats,the smallest copy number of repeats found in avrBs3 gene family by now.Three functional nuclear localization signals (NLSs) and an acidic activation domain (AAD) are also found in the C-terminal region of Arp3.