Comparative metabolic profiling of Vitis amurensis and Vitis vinifera during cold acclimation

Vitis amurensis is a wild Vitis plant that can withstand extreme cold temperatures. However, the accumulation of metabolites during cold acclimation (CA) in V . amurensis remains largely unknown. In this study, plantlets of V. amurensis and V. vinifera cv. Muscat of Hamburg were treated at 4 °C for 24 and 72 h, and changes of metabolites in leaves were detected by gas chromatography coupled with time-of-flight mass spectrometry. Most of the identified metabolites, including carbohydrates, amino acids, and organic acids, accumulated in the two types of grape after CA. Galactinol, raffinose, fructose, mannose, glycine, and ascorbate were continuously induced by cold in V. amurensis , but not in Muscat of Hamburg. Twelve metabolites, including isoleucine, valine, proline, 2-oxoglutarate, and putrescine, increased in V. amurensis during CA. More galactinol, ascorbate, 2-oxoglutarate, and putrescine, accumulated in V. amurensis , but not in Muscat of Hamburg, during CA, which may be responsible for the excellent cold tolerance in V. amurensis . The expression levels of the genes encoding β-amylase (BAMY), galactinol synthase (GolS), and raffinose synthase (RafS) were evaluated by quantitative reverse transcription-PCR. The expression BAMY ( VIT_02s0012 g00170 ) and RafS ( VIT_05s0077 g00840 ) were primarily responsible for the accumulation of maltose and raffinose, respectively. The accumulation of galactinol was attributed to different members of GolS in the two grapes. In conclusion, these results show the inherent differences in metabolites between V. amurensis and V. vinifera under CA. Grapes: staying out in the cold Studying how the wild grape Vitis amurensis copes with cold may help in breeding grape varieties that can grow at lower temperatures. To prevent frost damage, plants can increase cells’ sugar and protein contents, lowering the freezing point, and preventing ice crystal formation. V. amurensis , a wild grape native to Asia, grows well at low temperatures, but its cold-tolerance compounds have yet to be identified. Haiping Xin and Shaohua Li at the Chinese Academy of Sciences and co-workers profiled the compounds present in V. amurensis and V. vinifera cv. Muscat of Hamburg, a wine grape, following cold stress. V. amurensis cells were richer in a dozen compounds, including amino acids, organic acids, and putrescine, a component of the odor of decaying flesh. These results may help in developing grape varieties with increased cold tolerance.