Phytopathology. 2006 Jan;96(1):105-10. doi: 10.1094/PHYTO-96-0105.
ABSTRACT Crown gall disease, caused by Agrobacterium tumefaciens, remains a serious agricultural problem despite current biocontrol methods. Agrobacterium tumefaciens transfers single-stranded DNA (T-strands) into plant cells along with several virulence proteins, including a single-stranded DNA-binding protein (VirE2). In plant cells, T-strands are protected from nucleases and targeted to the nucleus by VirE2, which is essential for efficient transmission (transfer and integration) of T-strands. VirE1 is the secretory chaperone for VirE2; it prevents VirE2 from forming aggregates and from binding the T-strands in bacterial cells. Therefore, we hypothesized that sufficient quantities of VirE1 expressed in plant cells might block T-DNA transmission by preventing VirE2 from binding T-strands. Here we show that root explants from Arabidopsis thaliana plants that expressed virE1 formed 3.5-fold fewer tumors than roots from plants without virE1. Also, this resistance was specific for VirE2-mediated Agrobacterium transformation. Plants that have been genetically altered to resist crown gall may prove more effective than biological control.
摘要 尽管目前有生物防治方法，但根癌病（由根癌农杆菌引起）仍然是一个严重的农业问题。根癌农杆菌将单链 DNA（T-链）与几种毒力蛋白一起转移到植物细胞中，包括单链 DNA 结合蛋白（VirE2）。在植物细胞中，T-链被 VirE2 保护免受核酸酶的侵害，并被靶向到细胞核，这对于 T-链的有效传递（转移和整合）是必不可少的。VirE1 是 VirE2 的分泌伴侣；它防止 VirE2 在细菌细胞中形成聚集体和结合 T-链。因此，我们假设在植物细胞中表达足够量的 VirE1 可能会通过阻止 VirE2 结合 T-链来阻止 T-DNA 的传递。在这里，我们表明，表达 virE1 的拟南芥根外植体形成的肿瘤数量比没有 virE1 的根外植体少 3.5 倍。此外，这种抗性是针对 VirE2 介导的农杆菌转化的特异性的。已经遗传改变以抵抗根癌的植物可能比生物防治更有效。
