Abstract :
Low temperature (LT) is one of the most important plant abiotic stress factors which constrain plant production. Some of LT resistant
plants can survive freezing temperatures without injury throughout winter by metabolome changes during autumn that called cold
acclimation. Metabolic acclimation through the accumulation of effective metabolites is considered as fundamental strategy for
endurance of plant under sub-zero temperatures. Investigation of metabolic flexibility in over-wintering plants during the cold
acclimation offers new strategies that can be used to develop transgenic crop plants with improved tolerance to LT stress. The
accumulation of low molecular weight water-soluble compounds known as “compatible solutes” or “osmolytes” is the common strategy
adopted by overwintering plants to combat the freezing stress. The most common compatible solutes are betaines, sugars (mannitol,
sorbitol, and trehalose), polyols, polyamines, and amino acid (proline). Polyamines (putrescine, spermidine and spermine) are ubiquitous
polycationic aliphatic compounds that play important roles in the tolerance of plants against chilling stress, which is most likely achieved
by acting as oxidative machinery against chilling injury. The main goal of metabolome analysis under cold acclimation condition or LT
stress is to identify metabolites which are involved in re-establishing normal cellular metabolism and homeostasis or involved in
mediating tolerance mechanisms. The variation in the metabolite content of different genotypes may also introduce good forecasters for
LT tolerance phenotypes both in screening of genotypes and in plant breeding programs.
