Arabidopsis RETICULON-LIKE3 (RTNLB3) and RTNLB8 Participate in Agrobacterium-Mediated Plant Transformation.

can genetically transform various eukaryotic cells because of the presence of a resident tumor-inducing (Ti) plasmid. During infection, a defined region of the Ti plasmid, transfer DNA (T-DNA), is transferred from bacteria into plant cells and causes plant cells to abnormally synthesize auxin and cytokinin, which results in crown gall disease. T-DNA and several virulence (Vir) proteins are secreted through a type IV secretion system (T4SS) composed of T-pilus and a transmembrane protein complex. Three members of reticulon-like B (RTNLB) proteins, RTNLB1, 2, and 4, interact with VirB2, the major component of T-pilus. Here, we have identified that other RTNLB proteins, RTNLB3 and 8, interact with VirB2 in vitro. Root-based transformation assays with , or single mutants showed that the mutant was resistant to infection. In addition, and mutants showed reduced transient transformation efficiency in seedlings. or overexpression transgenic plants showed increased susceptibility to and infection. and transcript levels differed in roots, rosette leaves, cauline leaves, inflorescence, flowers, and siliques of wild-type plants. Taken together, and may participate in infection but may have different roles in plants.