Engineering Cold Stress Tolerance in Crop Plants

Abstract

Plants respond with changes in their pattern of gene expression and protein products when exposed to low temperatures. Thus ability to adapt has an impact on the distribution and survival of the plant, and on crop yields. Many species of tropical or subtropical origin are injured or killed by non-freezing low temperatures, and exhibit various symptoms of chilling injury such as chlorosis, necrosis, or growth retardation. In contrast, chilling tolerant species are able to grow at such cold temperatures. Conventional breeding methods have met with limited success in improving the cold tolerance of important crop plants involving inter-specific or inter-generic hybridization. Recent studies involving full genome profiling/ sequencing, mutational and transgenic plant analyses, have provided a deep insight of the complex transcriptional mechanism that operates under cold stress. The alterations in expression of genes in response to cold temperatures are followed by increases in the levels of hundreds of metabolites, some of which are known to have protective effects against the damaging effects of cold stress. Various low temperature inducible genes have been isolated from plants. Most appear to be involved in tolerance to cold stress and the expression of some of them is regulated by C-repeat binding factor/ dehydration-responsive element binding (CBF/DREB1) transcription factors. Numerous physiological and molecular changes occur during cold acclimation which reveals that the cold resistance is more complex than perceived and involves more than one pathway. The findings summarized in this review have shown potential practical applications for breeding cold tolerance in crop and horticultural plants suitable to temperate geographical locations.

Advances in physiological and molecular aspects of plant cold tolerance

“…A series of morphological, physiological, biochemical and molecular changes can be triggered in plants under the effect of abiotic stresses which eventually adversely affect the growth and productivity of crops. Therefore, plants respond and adapt in order to survive at the molecular and cellular levels in addition to physiological and biochemical responses (Sanghera et al 2011). It was reported that abiotic stresses can cause a decrease in yield of crops up to 50% resulting in very high economic losses (Vij & Tyagi 2007).…”

“…CBFs are discovered in all important field crops and some vegetable species (Sanghera et al 2011). CBF genes have been identified in a wide range of herbaceous (Mizoi et al 2012) and woody plants .…”

“…Manipulating the expression of genes as response to low-temperature stress is followed by increase in metabolites, some of which are proved to have a protective role against the damage of low-temperature stress. However, plants experience changes in their pattern of gene expression and protein products when they undergo lowtemperature stress and manipulating and engineering of CBF genes have shown potential practical application for breeding cold tolerance in crops and horticultural plants suitable for temperate regions (Sanghera et al 2011). …”

Impact of variety on resistance to cold stress at physiological levels in Linum usitatissimum

“…The exposing of plants to chilling or non-freezing temperatures will change biochemical and physiological activities in association with alteration in gene expression, bio-membrane lipid composition, and small molecule accumulation. In general, plants from temperate climatic regions are considered as chilling tolerant (Sanghera et al, 2011). Chilling sensitive varieties are typically tropical genotypes.…”

Bulk segregant analysis (BSA) for improving cold stress resistance in maize using SSR markers

“…Genes related to stress resistance can be elucidated through germination testing. Adaptation is important for the survival of plants and maintenance of crop yield (Sanghera et al, 2011). Early seasonal adaptability can be assessed by observing traits linked to cold tolerance (Hoffman et al, 2015).…”