Popova Elena, Kulichenko Irina, Kim Haeng-Hoon
K.A. Timiryazev Institute of Plant Physiology of Russian Academy of Sciences, Botanicheskaya 35, Moscow 127276, Russia.
Department of Agricultural Life Science, Sunchon National University, Suncheon 57922, Republic of Korea.
Biology (Basel). 2023 Apr 2;12(4):542. doi: 10.3390/biology12040542.
Cryopreservation is an effective option for the long-term conservation of plant genetic resources, including vegetatively propagated crops and ornamental plants, elite tree genotypes, threatened plant species with non-orthodox seeds or limited seed availability, as well as cell and root cultures useful for biotechnology. With increasing success, an arsenal of cryopreservation methods has been developed and applied to many species and material types. However, severe damage to plant material accumulating during the multi-step cryopreservation procedure often causes reduced survival and low regrowth, even when the optimized protocol is applied. The conditions at the recovery stage play a vital role in supporting material regrowth after cryopreservation and, when optimized, may shift the life-and-death balance toward a positive outcome. In this contribution, we provide an overview of the five main strategies available at the recovery stage to improve post-cryopreservation survival of in vitro plant materials and their further proliferation and development. In particular, we discuss the modification of the recovery medium composition (iron- and ammonium-free), exogenous additives to cope with oxidative stress and absorb toxic chemicals, and the modulation of medium osmotic potential. Special attention is paid to plant growth regulators used at various steps of the recovery process to induce the desired morphological response in cryopreserved tissues. Given studies on electron transport and energy provision in rewarmed materials, we discuss the effects of light-and-dark conditions and light quality. We hope that this summary provides a helpful guideline and a set of references for choosing the recovery conditions for plant species that have not been cryopreserved. We also propose that step-wise recovery may be most effective for materials sensitive to cryopreservation-induced osmotic and chemical stresses.
冷冻保存是长期保存植物遗传资源的有效方法，这些资源包括无性繁殖作物和观赏植物、优良树木基因型、具有非正统种子或种子可用性有限的濒危植物物种，以及对生物技术有用的细胞和根培养物。随着成功率的不断提高，一系列冷冻保存方法已经开发出来并应用于许多物种和材料类型。然而，即使应用了优化的方案，在多步骤冷冻保存过程中植物材料积累的严重损伤往往会导致存活率降低和再生率低下。恢复阶段的条件对于支持冷冻保存后材料的再生起着至关重要的作用，并且在优化后，可能会将生死平衡转向积极的结果。在本论文中，我们概述了恢复阶段可用的五种主要策略，以提高体外植物材料冷冻保存后的存活率及其进一步的增殖和发育。特别是，我们讨论了恢复培养基成分的修改（无铁和铵）、应对氧化应激和吸收有毒化学物质的外源添加剂，以及培养基渗透势的调节。特别关注在恢复过程的各个步骤中使用的植物生长调节剂，以诱导冷冻保存组织中所需的形态反应。鉴于对复温材料中电子传递和能量供应的研究，我们讨论了光照和黑暗条件以及光质的影响。我们希望这一总结为选择尚未进行冷冻保存的植物物种的恢复条件提供了有用的指导方针和一系列参考文献。我们还提出，逐步恢复对于对冷冻保存诱导的渗透和化学胁迫敏感的材料可能是最有效的。
