Plant cryopreservation: a molecular perspective

Cryopreservation has emerged as one of the most viable methods for the long-term conservation of plant species, but many plants are still recalcitrant to the stresses imposed by cryogenic processes, and robust cryopreservation protocols are lacking for some plant species. High-throughput omics-based approaches are being used to understand the molecular mechanisms governing the response to cryopreservation and associated stresses, but there are limited studies exploring the gene expression mechanisms and regulation governing survival and recovery post cryopreservation. Evidence, although scarce, has emerged that the energy metabolism and oxidative homeostasis pathways are most affected during the osmotic and dehydration stresses and up/down regulation of genes resulting in altered expression of their corresponding proteins has been observed in cryo-tolerant plant cells. Understanding the specific genes and proteins that determine cryo-tolerance or susceptibility can help develop conservation strategies for difficult to conserve species and overcome the challenges to their long-term conservation. The genes and proteins that are dynamically regulated during cryopreservation are the key to successful cryopreservation and plant regrowth. By characterizing these specific genes and proteins, researchers can better understand the mechanisms underlying cryo-tolerance and susceptibility and develop more effective and widely applicable conservation strategies for plant species.