Abstract:
Numerous environmental and endogenous factors affect the level of genetic diversity in natural populations. Genetic variability is the cornerstone of evolution and adaptation of species. However, currently, more and more plant species and local varieties (landraces) are on the brink of extinction due to anthropopression and climate change. Their preservation is imperative for the sake of future breeding programs. Gene banks have been created worldwide to conserve different plant species of cultural and economic importance. Many of them apply cryopreservation, a conservation method in which ultra-low temperatures (-135 °C to -196 °C) are used for long-term storage of tissue samples, with little risk of variation occurrence. Cells can be successfully cryopreserved in liquid nitrogen (LN) when the adverse effect of ice crystal formation and growth is mitigated by the removal of water and the formation of the so-called biological glass (vitrification). This state can be achieved in several ways. The involvement of key cold-regulated genes and proteins in the acquisition of cold tolerance in plant tissues may additionally improve the survival of LN-stored explants. The present review explains the importance of cryostorage in agronomy and presents an overview of the recent works accomplished with this strategy. The most widely used cryopreservation techniques, classic and modern cryoprotective agents, and some protocols applied in crops are considered to understand which parameters provide the establishment of high quality and broadly applicable cryopreservation. Attention is also focused on the issues of genetic integrity and functional genomics in plant cryobiology.
摘要:
许多环境和内源因素影响自然种群的遗传多样性水平。遗传变异是物种进化和适应的基石。然而,目前,由于人为和气候变化,越来越多的植物物种和当地品种(地方品种)濒临灭绝。为了将来的育种计划,必须保存它们。已经在世界范围内创建了基因库以保护具有文化和经济重要性的不同植物物种。他们中的许多应用冷冻保存,一种保存方法,其中使用超低温(-135°C至-196°C)长期保存组织样品,几乎没有变异发生的风险。当通过去除水和形成所谓的生物玻璃(玻璃化)来减轻冰晶形成和生长的不利影响时,可以将细胞成功地冷冻保存在液氮(LN)中。这种状态可以通过几种方式实现。关键的冷调节基因和蛋白质参与植物组织中耐寒性的获得可能会另外改善LN储存的外植体的存活。本综述解释了低温贮藏在农学中的重要性,并概述了使用该策略完成的最新工作。最广泛使用的冷冻保存技术,经典和现代的冷冻保护剂,和一些应用于作物的协议被认为是了解哪些参数提供了建立高质量和广泛适用的冷冻保存。注意力也集中在植物低温生物学中的遗传完整性和功能基因组学问题上。