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.
- Publication:
-
Proceedings of the National Academy of Science
- Pub Date:
- March 1983
- DOI:
- 10.1073/pnas.80.6.1660
- Bibcode:
- 1983PNAS...80.1660R