Temperature-dependent growth contributes to long-term cold sensing.

Area of Science:

• Plant biology
• Molecular biology
• Epigenetics

Background:

• Temperature is crucial for organismal growth and seasonal development.
• Plants must interpret long-term temperature changes to align development with seasons.
• Mechanisms for integrating long-term temperature exposure in plants are largely unknown.

Purpose of the Study:

• Investigate the molecular mechanisms underlying long-term temperature sensing in plants.
• Identify factors controlling the slow, seasonal upregulation of VERNALIZATION INSENSITIVE 3 (VIN3).
• Elucidate how plants interpret winter progression for developmental timing.

Main Methods:

• Forward genetic screen to identify mutations affecting VIN3 regulation.
• Analysis of the transcription factor NTL8 and its role in VIN3 expression.
• Computational simulation and experimental validation of NTL8 protein dynamics.
• Investigating the impact of temperature-dependent growth on protein dilution.

Main Results:

• Identified two dominant NTL8 mutations that constitutively activate VIN3 expression.
• Demonstrated that NTL8 protein accumulates slowly in the cold and directly upregulates VIN3.
• Showed that reduced NTL8 dilution due to slow growth at low temperatures is a key factor in slow accumulation.
• Established that temperature-dependent growth is exploited for long-term thermosensory information.

Conclusions:

• NTL8 acts as a key thermosensor for long-term temperature changes in plants.
• Protein dilution due to temperature-dependent growth is a mechanism for seasonal sensing.
• This mechanism provides long-term temperature information for VIN3 upregulation and winter interpretation.
• Indirect mechanisms involving temperature-dependent growth may be widespread in biological thermosensing.