Amur Grape VaMYB4a-VaERF054-Like Module Regulates Cold Tolerance Through a Regulatory Feedback Loop

Area of Science:

• Plant Science
• Molecular Biology
• Agricultural Science

Background:

• Cold stress significantly impacts grapevine growth, development, and productivity.
• Understanding the molecular mechanisms of grapevine cold stress response is crucial for agricultural advancement.

Purpose of the Study:

• To characterize the role of an APETALA2/ethylene response factor (AP2/ERF) gene, VaERF054-like, in grapevine cold tolerance.
• To investigate the molecular interaction between VaMYB4a and VaERF054-like in regulating cold stress response.

Main Methods:

• Gene expression analysis of VaERF054-like under cold stress.
• Promoter binding assays to determine VaMYB4a's interaction with VaERF054-like.
• Ethylene precursor and inhibitor treatments to assess pathway involvement.
• Overexpression studies in Vitis vinifera 'Chardonnay' calli and transgenic lines.
• In vivo and in vitro interaction studies between VaMYB4a and VaERF054-like.

Main Results:

• VaMYB4a directly binds and activates the VaERF054-like promoter, increasing its expression.
• VaERF054-like enhances cold tolerance by modulating ethylene and CBF signaling pathways.
• Overexpression of VaERF054-like confers increased freezing stress tolerance in grape calli and transgenic plants.
• VaMYB4a and VaERF054-like exhibit synergistic interaction, boosting cold tolerance via feedback regulation.

Conclusions:

• VaERF054-like is a key regulator of cold stress tolerance in grapes, acting downstream of VaMYB4a.
• The VaMYB4a-VaERF054-like regulatory module offers a promising target for developing cold-resistant grape varieties.
• Findings provide novel insights into grapevine's molecular response to cold stress.