Fig. 1: SLRL2 is a candidate transcription factor mediating ABA regulation of amylose content (AC) in rice.

a Rice AC in response to ABA or fluridone treatment. b AC of nced2 and dg1 mutants. c Expression of Wx in response to ABA or fluridone treatment. 100 μM ABA or 100 μM fluridone was sprayed every two days on rice panicles at 5 days after flowering (DAF), and grain samples were collected at 15 DAF. d Expression of Wx in the mature seeds of nced2 and dg1 mutants. In (a−d), data are means ± SD (n = 3 biological replicates) and comparisons are made by two-tailed Student’s t test. e Dual luciferase reporter assay to study the regulation of Wx gene expression to ABA treatment. Fluorescence ratio was measured after treatment with a series of ABA concentration gradients (0, 10, 50 and 100 μM) for 30 min. Error bars represent SD (n = 5 biological replicates). f Expression of SLRL2 and NF-YC9 in response to ABA or fluridone treatment. g Expression of SLRL2 and NF-YC9 under short-term ABA treatment. The 14-d-old rice seedlings were transferred to a medium containing 50 μM ABA, and rice samples were collected just before and after 30 and 60 min of ABA treatment, respectively. In (c, d, f, g), OsUBCI was used as an internal control to normalize gene expression. The expression level of the target gene was set to 1 for samples without ABA treatment or in the wild-type control. In (f, g), error bars represent SD (n = 3 biological replicates). h Dual luciferase reporter assay was used to examine the response of SLRL2 to different concentrations of ABA treatment. Error bars represent the SD (n = 5 biological replicates). i AC of the SLRL2 knockout and overexpression transgenic plants and the WT control. j AC of SLRL2 knockout and overexpression materials in response to ABA treatment. k Wx expression in SLRL2 knockout and overexpression materials in response to ABA treatment. Data in e-k are means ± SD (n = 5) biological replicates in (e, h); n = 3 biological replicates in (f, g, i, j, k). A two-sided Student’s paired t test was used to generate the P values in (f, i). In (e, g, h), different letters indicate significant differences (P < 0.05, one-way ANOVA with two-sided Tukey’s HSD test). In (j, k), a two-way ANOVA with two-sided Tukey’s HSD test was used to generate the P values, p < 0.05. P values are adjusted and shown in the Source Data file.