Overproliferation Phenotypes in PpAmiRcle, Ppclv1, and Pprpk2 Mutants
(A–E) Light micrographs of mutant gametophore morphology showing that gametophores (B) arrest, (C and E) develop multiple axes (pink arrows), and (C–E) develop swollen bases relative to (A) WT plants. The scale bar represents 200 μm.
(F and G) Confocal micrographs showing (F) overall gametophore morphology and (G) a branch initiating in a leaf axil in WT plants.
(H) Schematic showing Physcomitrella gametophore apex organization with an apical cell (pale yellow) and rotating division plane orientations.
(I–T) Confocal micrographs showing (I–K) PpcleAmiR1-3 mutant gametophore morphologies, with (I) overproliferation at the gametophore base and (J and K) disorganized growth with ectopic meristems.
(L–N) PpcleAmiR4-7 mutant gametophore morphologies with (L) split leaf phenotypes and (M and N) meristem overproliferation and termination.
(O–Q) Ppclv1a1b mutant gametophore morphology (O), with multiple growth axes and multiple meristems at the gametophore base (P and Q).
(R–T) Pprpk2 mutant gametophore morphology with multiple growth axes (R) and multiple meristems at the gametophore base (S and T).
Yellow arrowheads indicate regions of overproliferation or ectopic meristems. Yellow boxes show regions magnified from (J), (M), (P), and (S) to (K), (N), (Q), and (T). The scale bars represent 50 μm.