Reduced de-etiolation of hypocotyl growth in a tomato mutant is associated with hypersensitivity to, and high endogenous levels of, abscisic acid

0172199 - UEB-Q 20013078 RIV US eng J - Journal Article
Fellner, Martin - Zhang, R. - Pharis, R. - Sawhney, V.
Reduced de-etiolation of hypocotyl growth in a tomato mutant is associated with hypersensitivity to, and high endogenous levels of, abscisic acid.
Journal of Experimental Botany. Roč. 52, č. 357 (2001), s. 725-738. ISSN 0022-0957. E-ISSN 1460-2431
R&D Projects: GA ČR GV521/96/K117
Institutional research plan: CEZ:AV0Z5038910
Keywords : Abscisic acid * elongated mutant * fluridone
Subject RIV: EF - Botanics
Impact factor: 2.433, year: 2001

A recessive single gene mutant, 7B-1, in tomato was originally selected for its photoperiod-dependent male sterility. The 7B-1 mutant also has some pleiotropic effects including reduced light-induced inhibition, i.e. de-etiolation, of the hypocotyl in long days (LD), increased seed size and weight, and reduced transpiration rate. These traits led us to investigate the sensitivity of 7B-1 to exogenous hormones and the interaction of these responses with daylength. In LD, but not in short days (SD), 7B-1 was more sensitive than wild-type (WT) to exogenous abscisic acid (ABA) for inhibition of seed germination, root elongation and transpiration rate. 7B-1 mutant also exhibited reduced responses to exogenous gibberellin (GA3) for hypocotyl elongation, and to inhibitors of GA biosynthesis for seed germination and root and hypocotyl elongation. 7B-1 hypocotyls contained a higher level of endogenous ABA than WT in both photoperiods, although ABA levels were higher in LD than in SD. In contrast, growth-active GAs, i.e. GA1, GA3 and GA4, and IAA were low in the mutant hypocotyls. The 7B-1 mutant appears to be an ABA-overproducer, and the photoperiod-regulated ABA levels may be responsible for the hypersensitivity of the mutant to exogenous ABA.
Permanent Link: http://hdl.handle.net/11104/0069241