Gibberellin-induced changes in the translatable mRNA populations of stamens and shoots of gibberellin-deficient tomato

The gib1 mutant of tomato (Lycopersicon esculentum Mill.) is deficient in endogenous gibberellins and exhibits phenotypes including extreme dwarfism, reduced germination, and abnormal flower development, which are reversed by the application of gibberellic acid (GA₃). Previous work has demonstrated that, in stamens of the gib1 mutant, pollen mother-cell development arrests at the premeiotic G1 stage (Jacobsen and Olszewski 1991, Plant Physiol. 97, 409–414). Following GA₃ treatment of developmentally arrested flowers, pollen mother-cell development resumes and is synchronous. The present study examines gibberellin-induced changes in the translatable mRNA populations of developmentally arrested stamens and of vegetative shoots of the gib1 mutant. Following rescue of developmentally arrested stamens by treatment with GA₃, we consistently detected increases and decreases in the abundance of 14 and 20 in-vitro translation products, respectively. Some of these changes were first detected 8 h post treatment and therefore represent the first changes observed in stamens whose development has been rescued by GA₃ treatment. In vegetative gib1 shoots, the abundance of 13 in-vitro translation products decreased within 6–24 h after GA₃ treatment. However, no in-vitro translation products that increased in abundance after GA₃ treatment were detected.