Fig. 4: OsSTP28 functions upstream of GA2-oxidase mediated gibberellin metabolism pathway.
From: Sugar transporter modulates nitrogen-determined tillering and yield formation in rice
a Expression abundance of OsGA2ox3/5/8/9 in WT and stp28 mutants under LN or HN supply. OsGA2ox3/5/8/9 expression were assessed in shoot bases by qRT-PCR and normalized by OsActin1. Boxes show the first quartile, median, and third quartile; whiskers show the minimum and maximum values. n = 7 individual plants. b Gibberellin 2-oxidase (GA2ox) activities at shoot base of WT and stp28 lines under LN or HN supply. The shoot bases of 35-d-old rice seedlings (WT and stp28 lines) were collected for extracting GA2ox. Data are mean ± SD (n = 5 individual plants). c Schematic representation of the GA2ox catabolic pathway in higher plants. Bioactive GA1 (marked with green background) was inactivated to GA8 (marked with gray background) by GA2ox. d Comparison of the levels of two GA isoforms between WT and stp28 lines under LN or HN supply. ND not detected. Data are mean ± SD (n = 3 individual plants). e–g Phenotype (e), GA2ox activities (f) and tiller number (g) of WT and ga2ox5 lines under LN or HN supply. Scale bar, 20 cm. h–j Phenotype (h), GA2ox activities (i) and tiller number per plant (j) of WT, stp28-3, ga2ox5-1, and stp28-3/ga2ox5-1 double mutant plants under LN or HN supply. Scale bar, 20 cm. Data in (f, i) represent mean ± SD (n = 4 biological replicates). In (g, j), boxes show the first quartile, median, and third quartile; whiskers show the minimum and maximum values. n = 9 individual plants. In (a, b, d, f, g, i, j), Different letters indicated significant differences (P < 0.05, one-way ANOVA, Tukey’s HSD test).
