Abstract
•Understanding the mechanisms of cold stress response at the molecular level is crucial for improving crops against the stresses without yield penalty.•The ICE-CBF/DREB1 pathway is the most crucial plant cold acclimation response pathway.•There are limited research works on cold tolerance improvement in forage species which is most likely due to the complex genomic compositions of these non-model species.•High-throughput phenomics and genomics-based plant improvement methods and the latest genome-editing techniques are promising approaches to improve cold tolerance of forages.
Cold stress (CS) affects the survivability, geographical distribution, and yield stability of crops. Suitable management and agronomic practices can minimize the crop losses associated with cooler environments. However, agronomic practices alone can't support plants adequately to withstand the harsh cold. Therefore, exploring plants cold stress-responsive factors such as genetic, epigenetic, physiological, and cellular is crucial. This report discusses on cold stress effect, signal perception, signal transduction, gene expression, and associated molecular phenomena in plants. Three cold acclimation response pathways: Ca2+ mediated ICE1- CBF/ DREB1, hormonal, and reactive oxygen species (ROS), are elucidated. Also, this report summarizes the latest research work on genetics and genomics of forage species from the perspectives of cold tolerance improvement. In several instances, our hypotheses have been supported by a recent research output from our genetic analysis experiment on alfalfa (Medicago sativa L.) cold tolerance. We further review the importance of high-throughput genomics and phenomics for cold tolerance improvement in forage species and recommended implementing widely recognized techniques such as genomic selection (GS) and genome-wide association studies (GWAS) to develop climate-resilient cultivars. The transgenics and genome-edited cold-tolerant forage cultivars with low or no yield penalty must be the goals of future research.