Fig. 4

Direct regulation of OsSPL7 to LAX1 and Y2H of OsSPL7 and LAX2. a Expression analysis of LAX1 gene in the SPL7Flag and SPL7RNAi plants. b Sketch graph of the 19 SPL binding motifs in the 2 Kb promoter of LAX1 gene. Red bar indicates the ATG start codon, and black ones indicate the SPL binding GTAC motifs. Blue line labeled Y1H indicates the fragment site used in Y1H assay. Orange lines indicate the respective sites of the fragments used in ChIP assay. c Y1H assay of the binding of OsSPL7 and OsSPL13 proteins to the 18th and 19th motifs in the promoter of LAX1 gene. m18 and m19 indicate mutant 18th and 19th motifs. 2(18 + 19) means the fragment containing 2 tandem copies of normal 18th and 19th motifs, 2(m18 + 19) means the fragment containing 2 tandem copies of m18 and normal 19th motifs, and (18 + 19) + (m18 + m19) means the fragment containing one copy of normal 18th and 19th motif and one copy of m18 an m19, 2(m18 + m19) means the fragment containing 2 tandem copies of m18 and m19 motifs. d ChIP analysis using the binding of the OsSPL7 fused flag tag to the promoter of LAX1 gene. Single and double asterisks in (a) and (d) represent significant difference determined by the Student’s t-test at *P < 0.05 and **P < 0.01. e Y2H assay of OsSPL7 and LAX2, and OsSPL7 and LAX2. “SD-LT” stands for SD media devoid of Leu and Trp amino acids, “SD-LTAH” stands for SD media devoid of Leu, Trp, Ade and His amino acids