Potato (Solanum tuberosum L.) is considered to be frost-susceptible as short spells of frost can reduce the tuber yield and quality. Ice recrystallization inhibition (IRI) protein helps prevent growth of ice crystals in the cell apoplast during frost and help prevent damage associated with freezing stress. In this study, we investigated the in planta potential of Lolium perenne derived IRI3 transgene in improving the tolerance of transgenic potato lines for freezing stress. The codon optimized IRI3 transgene was introduced into potato cultivar Diamant through Agrobacterium mediated transformation. Three transgenic potato lines were successfully generated which were confirmed for transgene insertion and genomic integration by polymerase chain reaction and Southern blot. It was evident that the IRI3 transcript decreased in initial 24 h of cold stress treatment while the IRI3 mRNA expression up regulated in subsequent hours of cold treatment with maximum increase to 20 folds at 96 hrs post stress. A similar trend was also revealed in ion-leakage assay which showed that during cold stress, the transgenic potato lines depicted reduced ion leakage of 14 to 22% as compared to non-transgenic control plants. Further, the generated transgenic potato lines were tolerant to the frost spell in quarantine field conditions as compared to the non-transgenic potato lines. Additionally, the transgenic lines exhibited efficient recovery post frost injury in field conditions. The biochemical profiles of chlorophyll, proline and higher levels of antioxidant enzyme (superoxide dismutase, Catalase) activity and malondialdehyde levels showed that despite the phenotypic impact of low temperature, the transgenic potato lines quickly adjusted to maintain their cellular homeostasis post freezing stress by increasing the antioxidant defenses. This study suggests that up regulation of IRI3 transcript and regulatory network of cold stress response in transgenic potato lines improve frost tolerance and help stabilize yield in cultivated potato.

马铃薯 ( Solanum tuberosum L.) 被认为易受霜冻影响，因为短时间的霜冻会降低块茎产量和质量。冰重结晶抑制 (IRI) 蛋白有助于防止霜冻期间细胞质外体中冰晶的生长，并有助于防止与冷冻应激相关的损伤。在这项研究中，我们研究了黑麦草衍生的 IRI3 转基因在提高转基因马铃薯品系对冷冻胁迫的耐受性方面的植物潜力。将密码子优化的IRI3转基因通过农杆菌导入马铃薯品种Diamant介导的转化。成功产生了三个转基因马铃薯品系，通过聚合酶链反应和Southern印迹证实了它们的转基因插入和基因组整合。很明显，IRI3 转录物在冷应激处理的最初 24 小时内降低，而 IRI3 mRNA 表达在冷处理的后续小时内上调，在应激后 96 小时最大增加至 20 倍。离子泄漏试验也显示了类似的趋势，表明在冷胁迫期间，与非转基因对照植物相比，转基因马铃薯品系的离子泄漏减少了 14% 至 22%。此外，与非转基因马铃薯品系相比，所产生的转基因马铃薯品系能够耐受检疫田间条件下的霜冻。此外，在田间条件下，转基因品系在霜冻损伤后表现出有效的恢复。叶绿素、脯氨酸和更高水平的抗氧化酶（超氧化物歧化酶，过氧化氢酶）活性和丙二醛水平的生化特征表明，尽管存在低温的表型影响，转基因马铃薯品系通过增加抗氧化防御。这项研究表明，转基因马铃薯系中 IRI3 转录物的上调和冷应激反应的调节网络提高了耐霜性，有助于稳定栽培马铃薯的产量。过氧化氢酶) 活性和丙二醛水平表明，尽管低温的表型影响，转基因马铃薯品系通过增加抗氧化防御迅速调整以维持其冷冻应激后的细胞稳态。这项研究表明，转基因马铃薯系中 IRI3 转录物的上调和冷应激反应的调节网络提高了耐霜性，有助于稳定栽培马铃薯的产量。过氧化氢酶) 活性和丙二醛水平表明，尽管低温的表型影响，转基因马铃薯品系通过增加抗氧化防御迅速调整以维持其冷冻应激后的细胞稳态。这项研究表明，转基因马铃薯系中 IRI3 转录物的上调和冷应激反应的调节网络提高了耐霜性，有助于稳定栽培马铃薯的产量。