Shortening of the UI in ZS97A was caused by GA1-deficiency. (A) Application of exogenous GA1 to ZS97A and uniconazole to ZS97B. (a) ZS97A exhibited a serious panicle enclosure. (b) Application of 150 μM GA1 eliminated panicle enclosure in ZS97A. (c) ZS97B exhibited no panicle enclosure. (d) Application of 100 μM uniconazole caused panicle enclosure in ZS97B. All the treatments were performed at the early heading stage once a day for four days, and photographs were taken when the UIs had reached their final lengths. Scale bar=50 mm. (B) Endogenous GA1 level in the UI. (a) to (d) Samples for the assay of plant hormone were collected 48 h after the first treatment of (A, a) to (A, d), respectively. Each column represents the mean ±SE of three replicates of independently harvested plant material. FW, fresh weight. (C) Transcript levels of selected genes involved in the GA metabolic pathway in elongating UIs of ZS97A and ZS97B. RT-PCR was performed as described in the Materials and methods section with Actin as the control.
