Sprayed biodegradable liquid film improved the freezing tolerance of cv. Cabernet Sauvignon by up-regulating soluble protein and carbohydrate levels and alleviating oxidative damage

Abstract

Most cultivars of Vitis vinifera L. are very sensitive to cold. As an exogenous protectant, Biodegradable Liquid Film (BLF) is considered to protect winegrapes from low temperatures and dry winds for safe overwintering. This study aimed to reveal the physiological and biochemical mechanisms of BLF regulating the freezing tolerance of wine grapes. Groups of ten-year-old vines (Cabernet Sauvignon) were sprayed with BLF in November 2020 and 2021, or left untreated as a control treatment, and field plant mortality after overwintering were investigated. Branch samples were collected monthly for determination of biochemical indicators. Dormant two-year-old cuttings (Cabernet Sauvignon) were also used for the determination of relative expression levels of key genes. The results showed that the application of BLF reduced the branch semi-lethal temperature in January and February samples compared with control, and reduced the mortality of above-ground parts, branches and buds. The physiological status of shoots was greatly affected by the climatic conditions of the year, but BLF treatment increased the levels of soluble protein and soluble sugar, and also decreased the content of superoxide anion and malondialdehyde at most sampling times. Correlation analysis showed that the differences in freezing tolerance between BLF and no treated overwintering(CK) vines were mainly related to peroxidase activity, soluble sugar, reducing sugar and starch content. Low temperature stress activated the over expression of ICE1, CBF1, and CBF3, especially for 12h. BLF treatment significantly increased the expression levels of CBF1 and CBF3 under low temperature stress. Overall, these results demonstrate that BLF treatment protects vines from freezing damage by upregulating osmo-regulatory substances and alleviating oxidative damage.

Transcriptomics Reveals the Effect of Short-Term Freezing on the Signal Transduction and Metabolism of Grapevine

“…The electrolyte leakage of dormant cuttings branches was first measured in this study ( Figure 1 A), and two temperatures with relative conductivities close to 50% (−10 °C) and 80% (−16 °C) were selected for the next analysis. Based on our previous study [ 35 ], three time points of 3, 6, and 12 h of low-temperature stress were identified as sampling points. The malondialdehyde (MDA) content of branches at three time points was measured.…”

“…After natural dormancy in December, the vines in the pots were transferred to the high- and low-temperature alternating test chamber (YSGJS-408, Shanghai Lanhao Instrument & Equipment Co., Ltd., Shanghai, China) for freezing stress treatment. The low-temperature treatment referred to the method of Han et al [ 35 ], and the rate of cooling and rewarming was 4 °C/h. The branch samples for electrolyte leakage measured were treated at −6 °C, −8 °C, −10 °C, −12 °C, −14 °C, −16 °C, −18 °C, and −24 °C for 12 h and recovered at 4 °C for 12 h. The samples for transcriptomic analysis were treated at −10 °C and −16 °C for 3 h, 6 h, and 12 h, frozen in liquid nitrogen immediately and stored at −80 °C.…”

“…The relative electrical conductivity was determined according to the method of [ 35 ]. Samples (weighing 2.0 g) of branches were cut into 0.3–0.5-cm-thick slices and placed into a 25 mL test tube with a stopper.…”

Response Mechanisms of Woody Plants to High-Temperature Stress

“…It can neutralize reactive oxygen species generated by oxidative stress and adjust the intracellular redox balance [69], as well as reduce oxidative damage to cell membranes and intracellular organelle structures. Together, they maintain the stable growth and survival of woody plants under high-temperature conditions [70]. This shows that woody plants can improve the activity of antioxidant enzymes, reduce the oxidation of cells and maintain structural stability under high-temperature stress.…”

How Antioxidants, Osmoregulation, Genes and Metabolites Regulate the Late Seeding Tolerance of Rapeseeds (Brassica napus L.) during Wintering

“…Research has shown that high-chilling-tolerance cultivars accumulated more antioxidants, enzymes and osmoregulation substances in the anti-stress and environment adaption process compared with low-chilling-tolerance cultivars [41,42]. In more detail, the functions of the soluble protein and carbohydrate levels on the improvement in freezing tolerance were validated in sauvignon [43], while the functions of increased proline and carbohydrates under cold stress were also verified in alfalfa [44]. Furthermore, the enhanced chilling tolerance in watermelon achieved via suboptimal temperature acclimation was contributed to by improved photosynthetic adaptability and osmoregulation ability from substances such as proline, soluble sugar and sucrose [45].…”