PDF(Pubmed)
Abstract：
Potato (Solanum tuberosum) is the third most important food crop in the world. Potato tubers must be stored at cold temperatures to minimize sprouting and losses due to disease. However, cold temperatures strongly induce the expression of the potato vacuolar invertase gene (VInv) and cause reducing sugar accumulation. This process, referred to as \"cold-induced sweetening,\" is a major postharvest problem for the potato industry. We discovered that the cold-induced expression of VInv is controlled by a 200 bp enhancer, VInvIn2En, located in its second intron. We identified several DNA motifs in VInvIn2En that bind transcription factors involved in the plant cold stress response. Mutation of these DNA motifs abolished VInvIn2En function as a transcriptional enhancer. We developed VInvIn2En deletion lines in both diploid and tetraploid potato using clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated nuclease 9 (Cas9)-mediated gene editing. VInv transcription in cold-stored tubers was significantly reduced in the deletion lines. Interestingly, the VInvIn2En sequence is highly conserved among distantly related Solanum species, including tomato (Solanum lycopersicum) and other non-tuber-bearing species. We conclude that the VInv gene and the VInvIn2En enhancer have adopted distinct roles in the cold stress response in tubers of tuber-bearing Solanum species.
摘要：
马铃薯（Solanumtuberosum）是世界上第三重要的粮食作物。马铃薯块茎必须在低温下储存，以最大程度地减少发芽和由于疾病造成的损失。然而,低温强烈诱导马铃薯液泡转化酶基因（VInv）的表达并减少糖的积累。这个过程,被称为“冷诱导甜味”，是马铃薯产业的主要收获问题。我们发现VInv的冷诱导表达受200bp增强子控制，VInvIn2En,位于其第二个内含子。我们在VInvIn2En中鉴定了几个结合参与植物冷胁迫反应的转录因子的DNA基序。这些DNA基序的突变消除了VInvIn2En作为转录增强子的功能。我们使用成簇的规则间隔短回文重复序列（CRISPR）/CRISPR相关核酸酶9（Cas9）介导的基因编辑，在二倍体和四倍体马铃薯中开发了VInvIn2En缺失系。在缺失系中，冷藏块茎中的VInv转录显着降低。有趣的是,VInvIn2En序列在远缘茄属物种中高度保守，包括番茄（Solanumlycopersicum）和其他不含块茎的物种。我们得出的结论是，VInv基因以及VInvIn2En增强子在块茎茄属植物的块茎中的冷应激反应中具有不同的作用。
