|KIM, JOONYUP - UNIVERSITY OF MARYLAND|
|SICHER JR, RICHARD|
Submitted to: International Journal of Molecular Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/13/2020
Publication Date: 10/15/2020
Citation: Barnaby, J.Y., Kim, J., Mura, J.D., Fleisher, D.H., Tucker, M.L., Reddy, V., Sicher Jr, R.C. 2020. Varying atmospheric CO2 mediates the cold-induced CBF-dependent signaling pathway and freezing tolerance in "Arabidopsis". International Journal of Molecular Sciences. 21:7616. https://doi.org/10.3390/ijms21207616.
Interpretive Summary: Cold stress adversely affects plant growth and development and can result in partial or total crop failure. In the current study, varying carbon dioxide levels in the air altered the molecular responses of plants to cold treatments. Plants exposed to increased amounts of carbon dioxide in the air had severely inhibited freezing tolerance compared with plants treated with ambient or below ambient carbon dioxide. Therefore, it is likely that the ability of plants to resist frost damage in the future will be diminished by atmospheric change. Furthermore, it is well known that carbon dioxide levels in the air affect the opening and closing of pores on the leaf that regulate the water vapor exchange. Mutant plants with defective responses to carbon dioxide dependent leaf pore movements also had altered molecular responses to cold treatments and this increased or decreased freezing tolerance accordingly. These novel findings suggest that leaf pore movements and freezing tolerance in plants share a common sensory mechanism that detects carbon dioxide in the air. This study should alert agricultural scientists, plant breeders, and policy makers to the fact that atmospheric change may alter the frost hardiness of sensitive plants and crops.
Technical Abstract: Although prior studies have suggested a relationship between stomatal movements associated with [CO2] and plant cold responses, the molecular link between these two processes has been largely unknown. Here, we report that varying atmospheric [CO2] alters C-repeat Binding Factor (CBF)-mediated downstream cascades for freezing tolerance in Arabidopsis. In particular, the expression of CBFs and subsequent freezing tolerance are reduced in mutants that display a hypersensitive stomatal response to [CO2]. Opposite responses to [CO2] were observed in stomatal mutants that were insensitive to [CO2]. Results from the current study demonstrate that [CO2]-induced stomatal movements are linked to CBF-mediated cold signaling and this can ultimately alter freezing tolerance.