Metabolite profiling during cold acclimation of Lolium perenne genotypes distinct in the level of frost tolerance

Abstract

Abiotic stresses, including low temperature, can significantly reduce plant yielding. The knowledge on the molecular basis of stress tolerance could help to improve its level in species of relatively high importance to agriculture. Unfortunately, the complex research performed so far mainly on model species and also, to some extent, on cereals does not fully cover the demands of other agricultural plants of temperate climate, including forage grasses. Two Lolium perenne (perennial ryegrass) genotypes with contrasting levels of frost tolerance, the high frost tolerant (HFT) and the low frost tolerant (LFT) genotypes, were selected for comparative metabolomic research. The work focused on the analysis of leaf metabolite accumulation before and after seven separate time points of cold acclimation. Gas chromatography-mass spectrometry (GC/MS) was used to identify amino acids (alanine, proline, glycine, glutamic and aspartic acid, serine, lysine and asparagine), carbohydrates (fructose, glucose, sucrose, raffinose and trehalose) and their derivatives (mannitol, sorbitol and inositol) accumulated in leaves in low temperature. The observed differences in the level of frost tolerance between the analysed genotypes could be partially due to the time point of cold acclimation at which the accumulation level of crucial metabolite started to increase. In the HFT genotype, earlier accumulation was observed for proline and asparagine. The increased amounts of alanine, glutamic and aspartic acids, and asparagine during cold acclimation could be involved in the regulation of photosynthesis intensity in L. perenne. Among the analysed carbohydrates, only raffinose revealed a significant association with the acclimation process in this species.

A metabolomics study of ascorbic acid‐induced in situ freezing tolerance in spinach (Spinacia oleracea L.)

“…Reason for this is unclear but may have resulted from decreased breakdown of sucrose which accumulated at higher levels in AsA‐fed (Table ). Higher sucrose in AsA‐fed leaves may be associated with increased FT due to its well established role as a compatible solute under desiccation stress (Bocian et al, ; Kaplan et al, ).…”

“…Galactinol and myo‐inositol are involved in the biosynthesis of raffinose family oligosaccharides (RFOs) (Kannan et al, ; Sengupta, Mukherjee, Basak, & Majumder, ). RFOs also serve as compatible solutes under stress conditions (Bocian et al, ; Kaplan et al, ). Hincha, Zuther, and Heyer () noted that RFOs stabilized cellular membrane under desiccation stress via sugar–membrane interaction.…”

“…Higher sucrose in AsA-fed leaves may be associated with increased FT due to its well established role as a compatible solute under desiccation stress (Bocian et al, 2015;Kaplan et al, 2004).…”

Subcellular reprogramming of metabolism during cold acclimation in Arabidopsis thaliana

“…While various other amino acids, like, e.g., asparagine, aspartate, glutamin, glutamate and alanine accumulate in the cold in Arabidopsis (Klotke et al 2004) as well as in ryegrass (Bocian et al 2015), it was demonstrated that nitrate assimilation is impaired at low temperatures, with transcriptional downregulation occurring at the level of nitrate transporters, nitrate and nitrite reductase, glutamine synthetase and glutamate synthetase (Goel & Singh 2015). Considering that cold acclimation and the establishment of a new metabolic homeostasis at low temperature is energy demanding, a decline of nitrate assimilation appears rational and is consistent with the strong retardation of growth in the cold.…”

A metabolomics study of ascorbic acid-inducedin situfreezing tolerance in spinach (Spinacia oleraceaL.)

“…Reason for this is unclear but may have resulted from decreased breakdown of sucrose which accumulated at higher levels in AsA-fed (Supplementary Table 1). Higher sucrose in AsA-fed leaves may be associated with increased FT due to its well established role as a compatible solute under desiccation stress (Kaplan et al, 2004; Bocian et al, 2015).…”