The MdICE1/MdFAMA-MdTYDC Transcriptional Module Confers Cold Tolerance by Regulating Dopamine Metabolism in Apple.

Area of Science:

• Plant Science
• Molecular Biology
• Agricultural Science

Background:

• Low temperature poses significant challenges to fruit tree cultivation.
• The role of dopamine in enhancing plant cold tolerance is recognized, but its molecular mechanisms in apple (Malus domestica) are not well understood.

Purpose of the Study:

• To investigate the molecular mechanisms underlying dopamine-mediated cold tolerance in apple.
• To elucidate the regulatory pathways involved in dopamine biosynthesis and its impact on cold stress adaptation.

Main Methods:

• Exogenous dopamine application, gene overexpression (OE), and RNA interference (RNAi) of MdTYDC.
• Molecular genetic analyses including promoter binding assays and protein interaction studies.
• Analysis of reactive oxygen species, photosynthesis, stomatal function, anthocyanin biosynthesis, and CBF gene expression.

Main Results:

• Dopamine application improved cold resistance by mitigating reactive oxygen species, enhancing photosynthesis and stomatal function, and boosting anthocyanin and CBF gene expression.
• The MdICE1/MdFAMA regulatory module was identified as a key activator of MdTYDC transcription, amplifying dopamine biosynthesis.
• A positive feedback loop between exogenous dopamine, MdICE1, and MdFAMA expression was established, reinforcing cold tolerance.

Conclusions:

• Dopamine significantly enhances cold tolerance in apple through multiple physiological and molecular mechanisms.
• The MdICE1/MdFAMA-MdTYDC regulatory module plays a crucial role in orchestrating dopamine-mediated cold adaptation in apple.
• This study provides novel insights into stress adaptation mechanisms in perennial fruit crops, with potential applications in the fruit tree industry.