Y2SK2- and SK3-type dehydrins from Agapanthus praecox act as protectants to improve plant cell viability during cryopreservation
Y2SK2- and SK3-type dehydrins from Agapanthus praecox act as protectants to improve plant cell viability during cryopreservation
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来自百子莲的 Y2SK2 和 SK3 型脱水蛋白可作为保护剂，提高冷冻保存过程中植物细胞的活力
DOI：
10.1007/s11240-020-01780-y
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发表时间：
2020-02-14
影响因子：
3
通讯作者：
Ren, Li
中科院分区：
文献类型：
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作者：
Zhang, Di;Yang, Tianchen;Ren, Li
通过玻璃化法进行的植物低温保存通过使植物达到玻璃态进行低温储存来防止冰损伤。大多数被子植物种子脱水至其原始含水量的极低水平，积累胚胎发生后期丰富（莱亚）蛋白，并大大增加其细胞质粘度，从而在成熟过程中达到玻璃态。在这项研究中，两个莱亚家庭重组蛋白（DHN）百子莲（Y2 SK 2和SK 3），当添加到植物玻璃化溶液，拟南芥幼苗超低温保存后的存活率增加了一倍。伊文思蓝染色结果表明，Y2 SK 2和SK 3蛋白降低了低温保存过程中植物细胞质膜的损伤。Y2 SK 2和SK 3蛋白还能显著降低A.拟南芥幼苗因此，这些DHN可以减少在低温保存的复杂应力下过量的活性氧的产生和膜脂质过氧化损伤。此外，Y2 SK 2能有效提高过氧化物酶活性和过氧化氢酶2（CAT 2）表达水平; SK 3通过促进AsA-GSH循环活性，显著提高植物细胞抗坏血酸（阿萨）含量、Cu/Zn超氧化物歧化酶（Cu/Zn-SOD）和抗坏血酸过氧化物酶5（APX 5）表达，增强H2 O2清除能力。这些发现表明，Y2 SK 2和SK 3，在脱水步骤中添加的DHN，可以通过诱导高的抗氧化水平和积极的氧化应激反应来减轻细胞冷冻损伤，并作为保护剂，提高植物细胞冻存后的活力。应用甜菜碱优化植物超低温保存方案，甜菜碱能显著改善复合胁迫损伤，提高超低温保存细胞的存活率。
The cryopreservation of plants through vitrification prevents ice damage by bringing the plants to a glassy state for cryogenic storage. Most angiosperm seeds are dehydrated to extremely low levels of their original water content, accumulate late embryogenesis abundant (LEA) proteins, and greatly increase their cytoplasmic viscosity, thereby reaching a glassy state during maturation. In this study, two LEA family recombinant dehydrin (DHN) proteins (Y2SK2 and SK3) from Agapanthus praecox, when added to the plant vitrification solution, were found to double the survival rate of Arabidopsis thaliana seedlings after cryopreservation. Evans blue staining revealed that the Y2SK2 and SK3 proteins decreased the damage to the plasma membranes of plant cells during cryopreservation. Furthermore, the Y2SK2 and SK3 proteins significantly decreased the malondialdehyde and H2O2 contents, increased the glutathione (GSH) content, and downregulated NADPH oxidase (RbohA) in A. thaliana seedlings. Thus, these DHNs may reduce excessive reactive oxygen species production and membrane lipid peroxidation damage under the complex stresses of cryopreservation. Additionally, Y2SK2 can effectively enhance peroxidase activity and catalase2 (CAT2) expression levels; SK3 obviously improved ascorbic acid (AsA) content, as well as Cu/Zn superoxide dismutase (Cu/Zn-SOD) and ascorbate peroxidase 5 (APX5) expression in plant cells and enhanced H2O2 scavenging capacity by promoting the activity of the AsA-GSH cycle. These findings suggested that Y2SK2 and SK3, the DHNs added at the dehydration step, can relieve cell cryoinjury by inducing high antioxidant levels and positive oxidative stress responses and act as protectants, improving plant cell viability after cryopreservation. Application of dehydrins optimization plant cryopreservation protocol, dehydrins can significantly improve complex stress damage and enhance the cell viability from cryopreservation.