Jang Young-Sun, Sohn Soo-In, Wang Myeong-Hyeon
Division of Biotechnology, Kangwon National University, Chuncheon, Kangwon-do 200-701, South Korea.
Planta. 2006 Feb;223(3):449-56. doi: 10.1007/s00425-005-0100-4. Epub 2005 Sep 1.
Erwinia amylovora is a member of the harpin proteins that induces pathogen resistance and hypersensitive cell death in plants. To obtain tobacco plants displaying a hypersensitive response, the hrpN gene from Erwinia amylovora was cloned into vector pMJC-GB under the control of the rice cytochrome promoter and transfected into tobacco. Southern hybridization with a hrpN probe revealed that the gene was present in one copy in the transgenic plants. In addition, hrpN transcripts could be detected in transgenic plants but not in wild-type tobacco. The wild type gave 75 products in RAPD analysis with 12 primers while the transgenic plants gave 73, suggesting that hrpN gene had been integrated into the transgenic plant genomic DNA. The distribution of cell cycle phases in the wild type and transgenic plants was G0-G1: 71.25%, G2-M: 20.41%, S: 8.33%, while in transgenic plant was G0-G1: 54.95%, G2-M: 43.82%, S: 10.23%. The sizes of stomata and guard cells on transgenic leaves were similar to those of the wild type, but the epidermal cells were clearly smaller. The transgenic plants showed accelerated growth and development as well as enhanced resistance to Botrytis cinerea.
梨火疫病菌是一种能诱导植物产生病原体抗性和超敏细胞死亡的harpin蛋白成员。为了获得表现出超敏反应的烟草植株，将来自梨火疫病菌的hrpN基因在水稻细胞色素启动子的控制下克隆到载体pMJC - GB中，并转入烟草。用hrpN探针进行Southern杂交表明该基因在转基因植株中以单拷贝存在。此外，在转基因植株中可检测到hrpN转录本，而在野生型烟草中未检测到。野生型在使用12种引物的RAPD分析中产生75种产物，而转基因植株产生73种，这表明hrpN基因已整合到转基因植物基因组DNA中。野生型和转基因植株细胞周期各阶段的分布为：G0 - G1期：71.25%，G2 - M期：20.41%，S期：8.33%，而转基因植株中为G0 - G1期：54.95%，G2 - M期：43.82%，S期：10.23%。转基因叶片上气孔和保卫细胞的大小与野生型相似，但表皮细胞明显较小。转基因植株表现出生长发育加速以及对灰霉病的抗性增强。
