Genetic Dissection of the Relative Roles of Auxin and @entity15150 in the Regulation of Stem Elongation in Intact Light-Grown XXXX .

@entity6207 @entity52466 @entity308 @entity9634 @entity1051 @entity15150 @entity3587
Exogenous @entity15150 (GA) and @entity52466 ( @entity9634 [ @entity6207 ]) strongly stimulated stem elongation in dwarf GA1-deficient le mutants of light-grown @entity3587 ( @entity3587 .): @entity6207 elicited a sharp increase in growth rate after 20 min followed by a slow decline; the GA response had a longer lag (3 h) and growth increased gradually with time. These responses were additive. The effect of GA was mainly in internodes less than 25% expanded, whereas that of @entity6207 was in the older, elongating internodes. @entity6207 stimulated growth by cell extension; GA stimulated growth by an increase in cell length and cell number. Dwarf lkb GA-response-mutant plants elongated poorly in response to GA (accounted for by an increase in cell number) but were very responsive to @entity6207 . GA produced a substantial elongation in lkb plants only in the presence of @entity6207 . Because lkb plants contain low levels of @entity6207 , growth suppression in dwarf lkb mutants seems to be due to a @entity308 . GA may enhance the auxin induction of cell elongation but cannot promote elongation in the absence of auxin. The effect of GA may, in part, be mediated by auxin. Auxin and GA control separate processes that together contribute to stem elongation. @entity1051 in either leads to a dwarfed phenotype.
