Gross Briana L, Henk Adam D, Bonnart Remi, Volk Gayle M
University of Minnesota Duluth, 207 Swenson Science Building, 1035 Kirby Drive, Duluth, MN, 55812, USA.
USDA-ARS National Laboratory for Genetic Resources Preservation, 1111 S. Mason St., Fort Collins, CO, 80521, USA.
Plant Cell Rep. 2017 Mar;36(3):459-470. doi: 10.1007/s00299-016-2095-7. Epub 2016 Dec 20.
Transcripts related to abiotic stress, oxidation, and wounding were differentially expressed in Arabidopsis shoot tips in response to cryoprotectant and liquid nitrogen treatment. Cryopreservation methods have been implemented in genebanks as a strategy to back-up plant genetic resource collections that are vegetatively propagated. Cryopreservation is frequently performed using vitrification methods, whereby shoot tips are treated with cryoprotectant solutions, such as Plant Vitrification Solution 2 (PVS2) or Plant Vitrification Solution 3 (PVS3); these solutions remove and/or replace freezable water within the meristem cells. We used the model system Arabidopsis thaliana to identify suites of transcripts that are up- or downregulated in response to PVS2 and PVS3 treatment and liquid nitrogen (LN) exposure. Our results suggest that there are many changes in transcript expression in shoot tips as a result of cryoprotection and that these changes exceed the number detected as a result of LN exposure. In total, 180 transcripts showed significant changes in expression level unique to treatment with either the cryoprotectant or cryopreservation followed by recovery. Of these 180 transcripts, 67 were related to stress, defense, wounding, lipid, carbohydrate, abscisic acid, oxidation, temperature (cold/heat), or osmoregulation. The responses of five transcripts were confirmed using qPCR methods. The transcripts responding to PVS2 + LN suggest an oxidative response to this treatment, whereas the PVS3 + LN treatment invoked a more general metabolic response. This work shows that the choice of cryoprotectant can have a major influence on the patterns of transcript expression, presumably due to the level and extent of stress experienced by the shoot tip. As a result, there may be divergent responses of study systems to PVS2 and PVS3 treatments.
与非生物胁迫、氧化和创伤相关的转录本在拟南芥茎尖中对冷冻保护剂和液氮处理有差异表达。低温保存方法已在基因库中实施，作为一种备份通过营养繁殖的植物遗传资源收集的策略。低温保存通常使用玻璃化方法进行，即茎尖用冷冻保护剂溶液处理，如植物玻璃化溶液2（PVS2）或植物玻璃化溶液3（PVS3）；这些溶液去除和/或替代分生组织细胞内的可冷冻水。我们使用模式植物拟南芥来鉴定响应PVS2和PVS3处理以及液氮（LN）暴露而上调或下调的转录本组。我们的结果表明，由于冷冻保护，茎尖中的转录本表达有许多变化，并且这些变化超过了液氮暴露所检测到的数量。总共有180个转录本在冷冻保护剂处理或冷冻保存后恢复处理中表现出独特的表达水平显著变化。在这180个转录本中，67个与胁迫、防御、创伤、脂质、碳水化合物、脱落酸、氧化、温度（冷/热）或渗透调节有关。使用qPCR方法确认了五个转录本的响应。对PVS2 + LN有反应的转录本表明对该处理有氧化反应，而PVS3 + LN处理引发了更普遍的代谢反应。这项工作表明，冷冻保护剂的选择可能对转录本表达模式有重大影响，可能是由于茎尖所经历的胁迫水平和程度。因此，研究系统对PVS2和PVS3处理可能有不同的反应。
