Figure 1.

MpRSL1 Positively Regulates the Initiation of Rhizoids, Gemmae, Mucilage Papillae, and Slime Papillae in M. polymorpha

(A–X) Four genotypes are presented, one in each column: (first column) wild-type, (second column) Mprsl1-1 mutants, (third column) Mprsl1-1 OsACT1_pro:MpRSL1-A, and (fourth column) MpRSL1^GOF3. Six different stages are presented in rows.

(A–D) Rhizoids on 28-day-old thalli grown from gemmae. Scale bars represent 1 cm.

(E–H) Zero-day-old gemmae. Arrows highlight the position of pale rhizoid precursor cells. Scale bars represent 200 μm.

(I–L) Rhizoids developing on 4-day-old gemmae. Scale bars represent 1 mm.

(M–P) Surface view of gemma cups of 1-month-old plant. Scale bars represent 1 mm.

(Q–T) Toluidine-blue-stained longitudinal sections of gemma cups in a 1-month-old plant. Scale bars represent 500 μm.

(U–X) Toluidine-blue-stained longitudinal sections of gemma cups in a 1-month-old plant. The red arrow indicates a mucilage papilla; the black arrow indicates a gemma primordium. Scale bars represent 100 μm.

(Y) Wild-type, Mprsl1-1, and MpRSL1^GOF3 1-day-old gemmae. Arrows indicate slime papillae. Scale bars represent 20 μm.

See also Figure S1.