例如:"lncRNA", "apoptosis", "WRKY"

Agrobacterium tumefaciens increases cytokinin production in plastids by modifying the biosynthetic pathway in the host plant.

Proc. Natl. Acad. Sci. U.S.A.2005 Jul 12;102(28):9972-7. Epub 2005 Jul 05
Hitoshi Sakakibara 1 , Hiroyuki Kasahara , Nanae Ueda , Mikiko Kojima , Kentaro Takei , Shojiro Hishiyama , Tadao Asami , Kazunori Okada , Yuji Kamiya , Tomoyuki Yamaya , Shinjiro Yamaguchi
Hitoshi Sakakibara 1 , Hiroyuki Kasahara , Nanae Ueda , Mikiko Kojima , Kentaro Takei , Shojiro Hishiyama , Tadao Asami , Kazunori Okada , Yuji Kamiya , Tomoyuki Yamaya , Shinjiro Yamaguchi
+ et al

[No authors listed]

Author information
  • 1 Laboratories for Communication Mechanisms and Cellular Growth and Development, Plant Science Center, RIKEN, Suehiro 1-7-22, Tsurumi, Yokohama 230-0045, Japan. sakaki@postman.riken.go.jp

摘要


Agrobacterium tumefaciens infects plants and induces the formation of tumors called "crown galls" by integrating the transferred-DNA (T-DNA) region of the Ti-plasmid into the plant nuclear genome. Tumors are formed because the T-DNA encodes enzymes that modify the synthesis of two plant growth hormones, auxin and cytokinin (CK). Here, we show that a CK biosynthesis enzyme, Tmr, which is encoded by the Agrobacterium T-DNA region, is targeted to and functions in plastids of infected plant cells, despite having no typical plastid-targeting sequence. Evidence is provided that Tmr is an adenosine phosphate-isopentenyltransferase (IPT) that creates a new CK biosynthesis bypass by using 1-hydroxy-2-methyl-2-(E)-butenyl 4-diphosphate (HMBDP) as a substrate. Unlike in the conventional CK biosynthesis pathway in plants, trans-zeatin-type CKs are produced directly without the requirement for P450 monooxygenase-mediated hydroxylation. Consistent with the plastid localization of Tmr, HMBDP is an intermediate in the methylerythritol phosphate pathway, a plastid-localized biosynthesis route for universal isoprenoid precursors. These results demonstrate that A. tumefaciens modifies CK biosynthesis by sending a key enzyme into plastids of the host plant to promote tumorigenesis.