Figure 4. Spatiotemporal expression of Ms2.

(a,b) Ms2 expression in anthers. BW_Ms2, BW_Ms2:GFP, and GP_Ms2 are male-sterile transgenic plants JZ7-2_2, JZ19-6, and 22-1A, respectively. GLP was pooled from glumes, lemma and palea. (c) In situ hybridization of Ms2 mRNA in cross sections of LM15_RMs2 stamens. Hybridization with antisense probes was detected in pollen mother cells (PMC, c1), early uninucleate microspores (c2), and late uninucleate microspores (c3); hybridization with sense probes was negative in uninucleate microspores (c4). (d) Ms2:GFP in optical sections of an undissected male-sterile anther (from JZ19-6) at the PMC stage. (d1) A superimposed laser scanning confocal and light micrograph showing GFP across the end of an anther. GFP was detected in the middle layer (d2), tapetum (d3) and PMC (d4). The experiment was repeated three times. En, endothecium; Ep, epidermis; ML, middle layer; Ta, tapetum; uMsp, uninucleate microspore; dMT, degenerated middle layer and tapetum; duMsp, degenerated uninucleate microspore; M, the 250 bp DNA Ladder (GENEray, Shanghai, China). Scale bars, 25 μm (c) and 20 μm (d).