烟草PHYA基因的光温敏感性及生物学功能分析

Regulation of PHYA Gene on Photothermal Sensitivity and Related Traits in Tobacco

烟草是一种对光照和温度要求都非常严格的喜光喜温作物,为了降低烟草品种对光照和温度的敏感性,扩大烟草品种的光温适应范围和种植区域。本研究克隆了NtPHYA基因,采用生物信息学方法预测了该基因在烟草上的功能,利用CRISPR/Cas9基因编辑技术创制NtPHYA基因敲除突变体,分析了NtPHYA基因对烟草种子和烟苗光温敏感性及烟株生长的影响。结果表明,烟草NtPHYA与番茄SlPHYA基因的蛋白质序列相似度达92.15%,具有极为相似的理化性质,推测NtPHYA基因与番茄PHYA基因一样具有调控光温度敏感性和生长发育的功能;NtPHYA基因敲除突变体的光合色素含量、光合特性指标以及主要农艺性状均显著高于野生型,不同光温处理下突变体的NtPHYA基因表达量、种子萌发率均显著高于野生型。结果说明NtPHYA基因具有调控烟草光温度敏感性的功能,敲除NtPHYA基因能增加烟草光合色素含量、提高光合效率、促进烟株的生长,拓宽了烟草的光温适应范围和种植区域。本研究结果为解析NtPHYA基因对烟草生长发育的调控机理提供了理论参考和研究材料,对光温低敏感性烟草品种的选育具有重要的实践意义。

Tobacco is a photophilic and thermophilic crop with very strict requirements for light and temperature.In order to reduce the sensitivity of tobacco varieties to light and temperature,and expand the light and temperature adaptation range and planting area of tobacco varieties,the NtPHYA gene was cloned.Furthermore,the function of the gene in tobacco was predicted by bioinformatics methods.The CRISPR/Cas9 gene-editing technology was used to create the knockout mutant of the NtPHYA gene and the effects of the NtPHYA gene on the light and temperature sensitivity of tobacco seeds and seedlings and the growth of tobacco plants were analyzed.The results showed that the similarity between the NtPHYA gene and SlPHYA gene protein was 92.15%,which meant that these two genes may have similar physical and chemical properties.It was speculated that the NtPHYA gene had the same function as the tomato SlPHYA gene in regulating light temperature sensitivity and growth and development.The photosynthetic pigment content,photosynthetic characteristics and main agronomic traits activities of NtPHYA knockout mutants were significantly higher than those of wild type.The expression of the NtPHYA gene and seed germination rate of mutants under different light and temperature treatments were significantly higher than those of the wild type.The results showed that the NtPHYA gene had the function of regulating the light and temperature sensitivity of tobacco.Knock-out of the NtPHYA gene could increase the photosynthetic pigment content,improve photosynthetic efficiency,promote the growth of tobacco plants and broaden the light and temperature adaptation range and planting area of tobacco.The results provide theoretical reference and research materials for analyzing the regulation mechanism of the NtPHYA gene on tobacco growth and development and have important practical significance for the breeding of tobacco varieties with low sensitivity to light and temperature.