TaMYB96-5D regulates diketone biosynthesis and glaucousness by activating WAX1 expression in wheat

Area of Science:

• Plant Biology
• Molecular Genetics
• Agricultural Science

Background:

• Cuticular wax protects plants from environmental stress.
• Diketones are key components of wheat cuticular wax, influencing glaucousness.
• The WAX1 locus (TaDMH, TaDMP, TaDMC) is involved in diketone biosynthesis, but regulation remains unclear.

Purpose of the Study:

• Investigate the role of R2R3-type MYB transcription factor TaMYB96-5D in regulating wheat wax diketone biosynthesis and glaucousness.
• Determine the impact of TaMYB96-5D on wax composition, glaucousness, and drought tolerance.

Main Methods:

• Overexpression and knockout of TaMYB96-5D in wheat.
• Analysis of cuticular wax composition and content.
• Drought tolerance assays.
• Promoter binding assays (EMSA) and transcriptional activation analysis.

Main Results:

• Overexpression of TaMYB96-5D significantly increased total wax load, diketone content, glaucousness, and drought tolerance.
• Knockout of TaMYB96-5A/5B/5D led to reduced wax load, diketones, glaucousness, and drought tolerance, resulting in a glossy phenotype.
• TaMYB96-5D directly binds to the CAACCA motif in the promoters of TaDMH, TaDMP, and TaDMC, activating their transcription.

Conclusions:

• TaMYB96-5D is a crucial positive regulator of wheat wax diketone biosynthesis and glaucousness.
• This transcription factor plays a significant role in enhancing plant drought tolerance.
• Findings elucidate a key regulatory mechanism for diketone production and glaucousness in wheat.