Fig. 2. Expression analysis of zfl. (A) 192 bp RT-PCR product and position of the PstI site used to discern zfl1 and zfl2 transcripts. (B) Inverted ethidium bromide-stained gel images of zfl RT-PCR products restricted with PstI, and actin cDNA synthesis and PCR controls. Developmental stages are indicated. Vegetative shoot apical meristem (Veg. SAM) RNA includes the youngest two to three leaf primordia. Higher cycle numbers were used for this tissue because of low actin amplification. Vegetative leaves were collected prior to emergence from the leaf whorl. `Young tassel' RNA was collected at 34 days, just after reproductive transition, while the apex is producing branches and beginning to initiate spikelet pairs. `Older tassel' RNA was collected from inflorescences with differentiated stamens evident in the florets, but prior to tassel emergence. `Young ears' were 3-5 mm long and producing spikelet pairs and spikelets. `Older ears' were 1-1.5 cm long and had differentiated organs visible in their florets. (C-H) zfl expression analysis by mRNA in situ hybridization. (C) Developing ear. (D) Developing tassel. Developing spikelet-pairs (sp) are visible. (E) Male spikelets (s) developing from the spikelet pair meristem (sp). (F) Spikelet meristems (s) and initiating subtending glume primordia. (G) Branching spikelets forming upper (uf) and lower (lf) florets. Arrows indicate glume (gl) and primordia lemma (l). A floral meristem (fm) with stamens and gynoecium apparent is also visible. (H) Later male floret with developing stamen primordia (st), palea (p), lemma, lower florets (lf), lodicules (lo) and glumes (gl).

Return to article