Abstract: Cichorium intybus is a perennial herbaceous plant of the genus Cichorium,family Asteraceae and can be used as forage. The development of epidermal hair on chicory leaf may affect feeding value as well as forage quality. It has been documented that the GLABRA 2 (GL2) gene family may regulate the development of epidermal hair and trichome through different mechanisms. In this study,the CiGL2 gene was cloned,and the function of the gene was further analyzed. The open reading frame of CiGL2 was 2208 bp. Evolutionary analysis showed that chicory was more closely related to lettuce (Lactuca sativa var. ramosa). Subcellular localization test showed that the protein was localized in the nucleus. Leaves of over expressed plants showed an increase in the density of epidermal hair at the leaf margin and on the ventral surface of the leaf. Chicory GL2 mutant plants were obtained through CRISPR/Cas9 gene editing,and the length of epidermal hair on the ventral surface of the leaf was shorter and the density of epidermal hair decreased compared with that of the wild-type plants. This indicated that CiGL2 was associated with epidermal hair development in chicory. This study provided a theoretical basis for the functional study of the GL2 gene,and the mutant lines obtained could be important germplasm for chicory improvement.

Key words: Cichorium intybus, Epidermal hairs, CiGL2, CRISPR/Cas9

摘要： 菊苣(Cichorium intybus L.)，菊科菊苣属多年生草本生植物，是一种新型的牧草。菊苣叶片具有表皮毛，表皮毛可能影响其作为牧草的饲用价值。GLABRA 2(GL2)是植物转录因子，有研究显示其可能参与植物表皮毛的发育。本研究克隆了菊苣的GL2基因(CiGL2)，并通过遗传转化手段初步分析和验证该基因的功能。CiGL2开放阅读框为2208 bp，编码一个735个氨基酸的转录因子。进化分析表明，菊苣与生菜(Lactuca sativa L.)的亲缘关系较近；亚细胞定位显示，该蛋白定位于细胞核内；过表达植株叶片边缘、叶腹表皮毛密度较高。利用CRISPR/Cas9基因编辑技术获得菊苣CiGL2突变植株，与对照普通菊苣株系相比，突变植株叶腹面、叶片背面表皮毛长度较短，表皮毛密度下降。研究结果说明菊苣CiGL2基因功能可能与菊苣表皮毛发育相关。本研究为菊苣GL2基因功能分析提供理论基础，也为菊苣牧草品质的改良提供了创新种质资源。

关键词: 菊苣, 表皮毛, CiGL2, CRISPR/Cas9