Khanh Tran Dang, Xuan Tran Dang
Agricultural Genetics Institute, Pham Van Dong Street, Hanoi 122300, Vietnam.
Division of Development Technology, Graduate School for International Development and Cooperation (IDEC), Hiroshima University, Higashi Hiroshima 739-8529, Japan.
Pathogens. 2018 Apr 14;7(2):41. doi: 10.3390/pathogens7020041.
pv. causes serious stem canker in loquat () trees. This study was conducted to determine whether plasmids are involved with its virulence. The strain NAE89, which belonged to the B group, harbored two plasmids at approximately 6.2 and 50 Mdal that caused stem canker and halo leaf spots on loquat plants. Following digestion with HI and ligation into the HI cloning site of the broad range host cosmid pLAFR3, four DNA fragments at 3.8, 6.6, 12.3, and 22.8 kb were generated. Although the plasmid-encoded virulence gene A was undigested with the HI, the halo leaf spot gene may be adjacent to the A gene was digested. A pLAFR3 cosmid clone was introduced into the non-pathogenic PE0 and NAE89-1 strains by triparental matings and the pathogenicity was recovered. As a result, the pLAFR3 cosmid clone was introduced into the largest size DNA fragment of 22.8 kb and determined to be the causal agent of canker on the stem of the loquat. This study revealed that the A gene, previously found in the 50 Mdal plasmid, was also observed in the 22.8 kb DNA fragment.
pv. 会导致枇杷树出现严重的茎溃疡病。本研究旨在确定质粒是否与其毒力有关。属于B组的NAE89菌株携带两个大小约为6.2和50 Mdal的质粒，这些质粒会在枇杷植株上引起茎溃疡病和叶晕斑病。用HI酶切并连接到广宿主黏粒pLAFR3的HI克隆位点后，产生了3.8、6.6、12.3和22.8 kb的四个DNA片段。虽然质粒编码的毒力基因A未被HI酶切，但可能与A基因相邻的叶晕斑病基因被酶切了。通过三亲本杂交将一个pLAFR3黏粒克隆导入非致病性的PE0和NAE89 - 1菌株中，恢复了致病性。结果，pLAFR3黏粒克隆被导入了最大的22.8 kb DNA片段，并被确定为枇杷茎溃疡病的致病因子。本研究表明，先前在50 Mdal质粒中发现的A基因，在22.8 kb DNA片段中也被观察到。
