Mutations in these genes cause a subtle
increase in vegetative rosette leaves, but have no significant effect
on inflorescence cauline leaves (Schwarz et al., 2008). However,
in the double spl9 spl15 mutant, vegetative rosette leaf number
is significantly increased relative to the single mutants, leaves are
more rounded, and flowering time is delayed relative to wild type
(Schwarz et al., 2008). Furthermore, overexpression of AtSPL9
in hyponastic leaves1 (hyl1) mutants that have lowered miR156
expression,and therefore higherSPL gene expression,results in the
complete loss of the juvenile phase