Frost is an important abiotic stress for plants and crops because of the economic losses that are incurred. Plants have two mechanisms for freezing protection: freezing avoidance and freezing tolerance. The former prevents extrinsic and/or intrinsic ice nucleation, while the latter provides plants with tools to survive apoplastic ice formation, by several coordinated physiological and biochemical features such as the increase in cryoprotectants (metabolites and proteins) which in general maintain cell membrane and cells macromolecules stability, cause a freezing point depression or decrease the cell osmolarity preventing the severe cell dehydration caused by apoplastic freezing. Many products against freezing have been developed, and there are at least 20 products on the international market. Ten products mainly avoid ice formation by forming semi-permeable or permeable membranes that inhibit extrinsic ice nucleation over leaves, three products work for favouring tolerating ice formation in plants, and two use both mechanisms of action. Some kind of lipids, such as phospholipids and α-tocopherol, effectively maintain the stability and integrity of cell membranes, while some osmolytes (mainly polyols) decrease the freezing point of water, both inside and outside the cell, but also can interact with the polar moieties of phospholipids stabilizing membranes. Despite this, more information on products for crop protection against freezing is required in order to determine their effectiveness. New formulations that protect crops against freezing must include ingredients that employ both mechanisms. The use of lipids is likely to continue while new alternatives that reduce ice formation are evaluated, among which antifreeze and cryoprotective proteins may offer attractive alternatives.

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用于作物抗冰冻胁迫的化学产品：综述

霜冻是植物和农作物的重要非生物胁迫，因为它会造成经济损失。植物具有两种防冻机制：避免冻结和耐冻性。前者通过多种协调的生理和生化特性（例如增加防冻剂（代谢产物和蛋白质）的含量）来阻止植物外生和/或固有的冰核形成，而后者则为植物提供了可逆生冰形成的工具，通常可以维持细胞膜和细胞。大分子的稳定性，引起冰点降低或降低细胞渗透压，从而防止由质外性冷冻引起的严重细胞脱水。已经开发出许多防冻产品，并且国际市场上至少有20种产品。十种产品主要通过形成半透膜或渗透膜来抑制冰的形成，该膜可抑制叶片上的外在冰晶形核，三种产品有助于植物中耐冰的形成，而两种产品则同时利用两种作用机理。某些脂质，例如磷脂和α-生育酚，可以有效地维持细胞膜的稳定性和完整性，而某些渗透液（主要是多元醇）则可以降低细胞内外的水的冰点，但它们也可以与细胞内的蛋白质相互作用。磷脂稳定膜的极性部分。尽管如此，为了确定其有效性，还需要有关作物防冻产品的更多信息。保护农作物免受冻害的新配方必须包含采用两种机理的成分。