Fig. 8.

Expression of the chimeric WRKY21 repressor resulted in reduced phosphate (Pi) accumulation in root and suppression of PHT1;1 expression. (a) Phenotype of WRKY21‐SRDX transgenic lines and wild‐type plants grown hydroponically supplied with 300 μM Pi or 90 μM Pi. Bars, 15 cm. (b) Cellular Pi concentration analysis of Pro35S:WRKY21‐SRDX transgenic plants and wild‐type plants. Four‐leaf‐old seedlings were grown under half‐strength Kimura B nutrient solution supplied with 300 μM Pi or 90 μM Pi until the seventh leaf blades were fully expanded. Pi concentration was measured in shoot and root. (c) Effect of chimeric WRKY21 repressor on transcript levels of four PHT1 genes. Plant roots were collected for RNA extraction and RT‐qPCR analysis. The rice housekeeping gene OsActin1 (LOC_Os03g50885) was used as an internal control. Error bars indicate SD (n = 4). Data significantly different from the corresponding controls are indicated (*, P < 0.05; **, P < 0.01; Student’s t‐test). FW, fresh weight.