College of Landscape Architecture, Northeast Forestry University, Harbin, China.
Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, Northeast Forestry University, Harbin, China.
Plant Biol (Stuttg). 2022 Oct;24(6):1066-1075. doi: 10.1111/plb.13452. Epub 2022 Jul 21.
Breeding for flower cold resistance is a priority for flower breeding research in northern China. The identification of cold resistance genes will not only provide genetic resources for cold resistance breeding, but also form a basis for the study of plant cold resistance mechanisms. Based on the flower transcriptome of Iris laevigata, 20 R2R3-MYBs were identified and comprehensive analysis, including conservative domain, phylogenetic analyses and functional distribution, were performed for R2R3-MYBs. Expression patterns of the abiotic stress genes under cold stress were detected, the upregulated gene was genetically transformed into tobacco, and the related physiological indicators of the transgenic tobacco were measured. A novel cold resistance gene, IlMYB306, was obtained. qRT-PCR indicated that IlMYB306 was dramatically induced by cold stress and was significantly upregulated in roots. The free proline content, MDA, SOD and POD activity of the transgenic tobacco improved after cold stress, and the chlorophyll content decreased slowly. In addition, overexpression of IlMYB306 improved cold resistance of the seeds. SEM results showed leaves of transgenic tobacco had obvious folds, more grooves and bulges on the lower leaf surface. Overall, we report a novel cold resistance R2R3-MYB gene, IlMYB306, in the flower of I. laevigata, which could improve tobacco cold stress tolerance by thickening the waxy layer, increasing antioxidant activity and the content of proline.
培育花卉的抗寒性是中国北方花卉育种研究的重点。抗寒基因的鉴定不仅为抗寒育种提供了遗传资源，也为研究植物抗寒机制奠定了基础。本研究基于鸢尾属黄花鸢尾的花转录组数据，鉴定了 20 个 R2R3-MYB 基因，并对其进行了保守结构域、系统进化分析和功能分布的综合分析。检测了非生物胁迫基因在冷胁迫下的表达模式，将上调基因遗传转化到烟草中，并测量了转基因烟草的相关生理指标。获得了一个新的抗寒基因 IlMYB306。qRT-PCR 结果表明，IlMYB306 受冷胁迫诱导显著上调，在根中表达量较高。转基因烟草在冷胁迫下的游离脯氨酸含量、MDA、SOD 和 POD 活性提高，叶绿素含量下降缓慢。此外，过表达 IlMYB306 提高了种子的抗寒性。SEM 结果表明，转基因烟草叶片明显褶皱，下表皮有更多的凹槽和凸起。总之，我们在黄花鸢尾的花中报告了一个新的抗寒 R2R3-MYB 基因 IlMYB306，它可以通过增加蜡质层厚度、提高抗氧化活性和脯氨酸含量来提高烟草的抗冷胁迫能力。
