Wheat MIXTA-like Transcriptional Activators Positively Regulate Cuticular Wax Accumulation.

MIXTA-like transcription factors AtMYB16 and AtMYB106 play important roles in the regulation of cuticular wax accumulation in dicot model plant , but there are very few studies on the MIXTA-like transcription factors in monocot plants. Herein, wheat MIXTA-like transcription factors TaMIXTA1 and TaMIXTA2 were characterized as positive regulators of cuticular wax accumulation. The virus-induced gene silencing experiments showed that knock-down of wheat and expressions resulted in the decreased accumulation of leaf cuticular wax, increased leaf water loss rate, and potentiated chlorophyll leaching. Furthermore, three wheat orthologous genes of (, , and ) and their function in cuticular wax deposition were reported. The silencing of by BSMV-VIGS led to reduced loads of leaf cuticular wax and enhanced rates of leaf water loss and chlorophyll leaching, indicating the essential role of the gene in the deposition of wheat cuticular wax. In addition, we demonstrated that TaMIXTA1 and TaMIXTA2 function as transcriptional activators and could directly stimulate the transcription of wax biosynthesis gene and wax deposition gene . The above results strongly support that wheat MIXTA-Like transcriptional activators TaMIXTA1 and TaMIXTA2 positively regulate cuticular wax accumulation via activating and gene transcription.