A new molecular mechanism for the control of plant adaptation to frost has been unveiled.

A study published in the journal Plant Physiology and carried out by the Plant Molecular Biology Laboratory of the Margarita Salas Center for Biological Research (CIB-CSIC), led by researchers Julio Salinas and Rafael Catalá, reveals new molecular mechanisms that control the adaptation of plants to frost.

Understanding the mechanisms that control the response of plants to extreme environmental conditions is essential to developing biotechnological strategies to address food security in the context of climate change. One of the objectives of the Plant Molecular Biology group is to study the process of acclimatization to low temperatures, an adaptive response by which plants increase their tolerance to frost. The acclimation process involves a series of physiological changes finely regulated at the level of gene expression. In Arabidopsis (Arabidopsis thaliana) the CBF family of transcription factors (CBF1-3) plays a prominent role in this regulation. Transcription of CBFs is activated rapidly and transiently during the acclimation process, and any alteration of this expression pattern prevents the correct development of the process.

Gómez-Martínez et al. unveil a new mechanism for the regulation of CBF expression during the acclimation process. After the peak of CBF3 expression, the Polycomb Repressor Complex 2 (PRC2) deposits the repressor epigenetic mark H3K27m3 in its coding region attenuating its expression and placing it at the appropriate levels for the correct development of the adaptive response. This mechanism is mediated by the cold-inducible long non-coding RNA (lncRNA) SVALKA that physically interacts with PRC2 and transports it to the chromatin of CBF3.

These results have revealed the existence of an SVALKA-PRC2 epigenetic regulation module that ensures the correct induction profile of CBF3 during the acclimation process and, therefore, its correct development.

Reference: SVALKA-POLYCOMB REPRESSIVE COMPLEX2 module controls C-REPEAT BINDING FACTOR3 induction during cold acclimation. Diego Gómez-Martínez, Javier Barrero-Gil, Eduardo Tranque, María Fernanda Ruiz, Rafael Catalá and Julio Salinas. Plant Physiology, kiad671, https://doi.org/10.1093/plphys/kiad671