PLANT PHYSIOLOGY , Vol 103, Issue 1 165-170, Copyright © 1993 by American Society of Plant Biologists
|
MOLECULAR BIOLOGY AND GENE REGULATION |
A Mutant of Arabidopsis thaliana with a Reduced Response to Fusicoccin. I
S. Gomarasca, C. Vannini, A. Venegoni, A. Talarico, M. T. Marre and C. Soave
Dipartimento di Biologia, Universita di Milano and Centro di Studio del Consiglio Nazionale delle Ricerche per la Biologia Cellulare e Molecolare delle Piante, Via G. Celoria 26-20133 Milano, Italy
Because fusicoccin (FC) has the the capacity to promote solute uptake, a
selective procedure for isolating mutants of Arabidopsis thaliana with a
reduced response to the toxin has been developed. The procedure is based on
the incubation of A. thaliana seedlings in a solution containing the cation
Paraquat (Pq) at a concentration that per se does not produce bleaching of
the leaves upon illumination but does in the presence of FC because of the
increased uptake of the toxic cation. Using this procedure, we identified,
among the progenies of 2010 M1 ethyl methanesulfonate-mutagenized plants,
two mutants that stay green after exposure to FC and Pq. Some properties
and inheritance of one of the two mutants (5-2) are described. Morphology
of mutant plants is almost indistinguishable from that of the wild type.
However, 5-2 seeds germinate and produce viable seedlings in the presence
of FC plus the aminoglycoside antibiotic hygromycin B: plants of the mutant
do not wilt when exposed to FC and stomata do not open or open only
partially. In the presence of FC, the mutant appears less responsive than
the wild type as far as the increment in fresh weight, the enlargement of
leaf disc area, or the stimulation of H+ extrusion is concerned.
Inheritance of the trait is monogenic dominant or semidominant, depending
on the test used.
