ZmDREB1A Regulates myo-Inositol-1-phosphate Synthase 2 Controlling Maize Germination at Low Temperatures

Area of Science:

• Plant Biology
• Molecular Genetics
• Agricultural Science

Background:

• Transcription factor DREB1A is known to improve plant tolerance to chilling stress.
• The specific role of DREB1A in regulating seed germination at low temperatures was previously unknown.

Purpose of the Study:

• To investigate the function of maize DREB1A in low-temperature seed germination.
• To elucidate the molecular mechanism by which ZmDREB1A influences germination under cold conditions.

Main Methods:

• Utilized maize mutants (zmdreb1a and zmmips2) and overexpression lines.
• Analyzed gene expression (ZmMIPS2) and promoter activity.
• Performed in vitro and in vivo binding assays for ZmDREB1A and ZmMIPS2 promoter.

Main Results:

• Maize zmdreb1a mutant seeds showed reduced ZmMIPS2 expression and lower germination rates at low temperatures.
• ZmDREB1A overexpression increased ZmMIPS2 expression; DRE motif mutation abolished this effect.
• ZmDREB1A directly binds to DRE motifs in the ZmMIPS2 promoter.
• zmmips2 mutants were sensitive, while ZmMIPS2 overexpressors were tolerant to low-temperature germination.

Conclusions:

• ZmDREB1A is a key regulator of maize seed germination under low temperatures, acting via ZmMIPS2.
• Understanding this pathway can aid in breeding crops with improved cold tolerance during germination.