Morton Elise R, Fuqua Clay
Department of Biology, Indiana University, Bloomington, Indiana, USA.
Curr Protoc Microbiol. 2012 Feb;Chapter 1:Unit3D.1. doi: 10.1002/9780471729259.mc03d01s24.
Agrobacterium species are plant-associated relatives of the rhizobia. Several species cause plant diseases such as crown gall and hairy root, although there are also avirulent species. A. tumefaciens is the most intensively studied species and causes crown gall, a neoplastic disease that occurs on a variety of plants. Virulence is specified by large plasmids, and in the case of A. tumefaciens this is called the Ti (tumor-inducing) plasmid. During pathogenesis, virulent agrobacteria copy a segment of the Ti plasmid and transfer it to the plant, where it subsequently integrates into the plant genome and expresses genes that result in the disease symptoms. A. tumefaciens has been used extensively as a plant genetic engineering tool, and is also a model microorganism that has been well studied for host-microbe associations, horizontal gene transfer, cell-cell communication, and biofilm formation. This unit describes standard protocols for laboratory cultivation of A. tumefaciens.
土壤杆菌属是与根瘤菌相关的植物共生菌。尽管也有无毒菌株，但有几个种会引发植物病害，如冠瘿病和毛根病。根癌土壤杆菌是研究最为深入的种，会引起冠瘿病，这是一种发生在多种植物上的肿瘤性疾病。毒性由大质粒决定，对于根癌土壤杆菌而言，这种质粒被称为Ti（致瘤）质粒。在发病过程中，有毒土壤杆菌会复制Ti质粒的一段并将其转移到植物中，随后该段质粒整合到植物基因组中并表达导致病害症状的基因。根癌土壤杆菌已被广泛用作植物基因工程工具，也是一种在宿主 - 微生物相互作用、水平基因转移、细胞间通讯和生物膜形成等方面得到充分研究的模式微生物。本单元描述了根癌土壤杆菌实验室培养的标准方案。
