Xie Jiajian, Wang Xifeng, Li Feiwu, Peng Yufa, Zhou Guanghe
State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100094, PR China.
J Microbiol. 2007 Jun;45(3):219-26.
Insertion sequence IS1112 is a repetitive element with a relatively high number of copies in Xanthomonas oryzae pv. oryzae (Xoo), the causal agent of bacterial blight of rice (Oryza sativa L.). Three new loci of IS1112 were identified in seven Chinese strains of Xoo using a single oligonucleotide primer J3; 5'-GCTCAGGTCAGGTGGCCTGG-3' by insertion-sequence-based polymerase chain reaction (IS-PCR). Among the three new loci of IS1112, two were located in the open-reading frame region of genes fhuA and cirA, which encode TonB-dependent receptors, and the third in ISXo2, another type of insertion sequence in Xoo genome. Three variants of IS1112 were identified in those three loci based on their sequence similarities: two were identical to IS1112a and IS1112b, reported in strain PXO86 from the Philippines, while the third was a new member of IS1112, defined as IS1112d. Inserting IS1112 in gene fhuA caused three bases, GGT, to be duplicated at the target site, but inserting it in gene cirA did not cause any duplication in the target site. The diversity of IS1112 sequence and insertion loci in Xoo genome and their potential effects are discussed.
插入序列IS1112是一种重复元件，在水稻白叶枯病菌（Xanthomonas oryzae pv. oryzae，Xoo）中具有相对较高的拷贝数，Xoo是水稻细菌性条斑病的病原菌。利用基于插入序列的聚合酶链反应（IS-PCR），使用单一寡核苷酸引物J3（5'-GCTCAGGTCAGGTGGCCTGG-3'）在7株中国Xoo菌株中鉴定出IS1112的3个新位点。在IS1112的3个新位点中，有2个位于编码TonB依赖性受体的fhuA和cirA基因的开放阅读框区域，第3个位于Xoo基因组中另一种插入序列ISXo2中。根据序列相似性，在这3个位点鉴定出IS1112的3个变体：2个与菲律宾菌株PXO86中报道的IS1112a和IS1112b相同，而第3个是IS1112的新成员，定义为IS1112d。将IS1112插入fhuA基因导致靶位点处3个碱基GGT重复，但将其插入cirA基因未导致靶位点处任何重复。讨论了Xoo基因组中IS1112序列和插入位点的多样性及其潜在影响。
