近日，合肥工业大学科研人员首次成功探明功能性基因DFR1在植物面对恶劣环境时调节适应能力的机制，为提高农经作物抗冻抗旱能力开辟了新的理论路径。相关研究结果发表在《细胞报告》（Cell Reports）上。

为探明功能性基因DFR1调控机制，该校食品科学与工程学院曹树青课题组与刘永胜课题组合作，成功克隆该基因，并在模式植物拟南芥中开展系列研究。研究证实，该基因通过调控植物细胞中脯氨酸的动态平衡，实现植物对各种环境胁迫的应答反应。

在干旱和低温等恶劣环境下，该基因编码的DFR1蛋白与脯氨酸降解途径上的两个关键酶均发生相互作用，并显著抑制其活性，从而阻断整个脯氨酸降解途径，使得脯氨酸的含量增加，进而增加植物对恶劣环境的耐受性。

实验结果表明，将模式植物置于干旱或低温环境后，DFR1基因的表达量急剧增加400倍，植物细胞中脯氨酸含量也随之升高50倍，并在恶劣环境中一直维持在较高水平。在该基因的调控作用下，DFR1过表达植物对恶劣环境的耐受性大幅提高，在持续18天重度干旱或12小时-8℃冷冻处理条件下，其植株存活率较野生型提升3至4倍。

据介绍，通过基因编辑技术提高该基因的表达水平，这一成果可大幅提升植物在恶劣环境中的存活率和生物量，在农经作物抗逆分子育种等领域具有极其广阔的应用前景。（来源：中国科学报 周慧 杨保国）

DFR1-Mediated Inhibition of Proline Degradation Pathway Regulates Drought and Freezing Tolerance in Arabidopsis

Abstract  Proline accumulation is one of the most important adaptation mechanisms for plants to cope with environmental stresses, such as drought and freezing. However, the molecular mechanism of proline homeostasis under these stresses is largely unknown. Here, we identified a mitochondrial protein, DFR1, involved in the inhibition of proline degradation in Arabidopsis. DFR1 was strongly induced by drought and cold stresses. The dfr1 knockdown mutants showed hypersensitivity to drought and freezing stresses, whereas the DFR1 overexpression plants exhibited enhanced tolerance, which was positively correlated with proline levels. DFR1 interacts with proline degradation enzymes PDH1/2 and P5CDH and compromises their activities. Genetic analysis showed that DFR1 acts upstream of PDH1/2 and P5CDH to positively regulate proline accumulation. Our results demonstrate a regulatory mechanism by which, under drought and freezing stresses, DFR1 interacts with PDH1/2 and P5CDH to abrogate their activities to maintain proline homeostasis, thereby conferring drought and freezing tolerance.

原文链接：https://www.cell.com/cell-reports/pdf/S2211-1247(18)30540-0.pdf