Multiple mutations in the T region of the Agrobacterium tumefaciens tumor-inducing plasmid.

Abstract

Three genetic loci affecting tumor morphology lie within pTiA6NC T-DNA: tms, tmr, and tml. Using deletions and multiple transposon insertions, we constructed tumor-inducing (Ti) plasmids representing every possible double and triple mutant combination. tms tmr and tms tmr tml mutants did not incite tumors on most plants and produced a very weak response on a few other hosts but tms tml and tmr tml mutants were virulent. Thus, either tms+ or tmr+ alone can promote significant tumor growth but tml+ by itself is not sufficient. On hosts where tms mutants induce tumors accompanied by shoot proliferation, addition of a tml mutation reduces or eliminates shoot proliferation, suggesting that tml+ promotes shoot development. The small calli incited by tms tmr and tms tmr tml mutants contain agropine, an indication that these plant cells incorporate T-DNA in the absence of substantial tumor growth.

• Authors: L W Ream, M P Gordon, E W Nester
• Journal: Proceedings of the National Academy of Sciences of the United States of America (Proc Natl Acad Sci U S A) Vol. 80 Issue 6 Pg. 1660-4 (Mar 1983) ISSN: 0027-8424 [Print] United States
• PMID: 6300864 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• DNA Transposable Elements
• Plant Growth Regulators

Topics

• DNA Transposable Elements
• Mutation
• Plant Growth Regulators (physiology)
• Plant Tumors (genetics)
• Plasmids
• Rhizobium (genetics)