《植物生理学报》 2021, 57(2): 362-372

无籽刺梨果实表皮毛形态结构及发育过程中相关基因的表达

马文涛^1,2，鲁敏¹，王道静¹，安华明^1,2,*

¹贵州大学农学院/贵州省果树工程技术研究中心, 贵阳550025；²山地植物资源保护与种质创新教育部重点实验室, 贵阳550025

通信作者：安华明；E-mail: hman@gzu.edu.cn

摘　要：

以无籽刺梨花托发育开始至果实成熟时期的果实为材料, 研究其表皮毛的类型、解剖结构、化学组成和相关基因的表达变化。结果表明, 无籽刺梨果实表皮毛早期由鞭状表皮毛、针状表皮毛和长柄头状有腺表皮毛组成, 后期鞭状表皮毛脱落, 针状表皮毛和长柄头状有腺表皮毛木质化成果刺。果刺由角质层、表皮层和薄壁细胞等组成; 针状果刺和头状果刺在细胞超微结构上存在明显差异。果刺的化学成分主要是木质素、木栓质、纤维素及半纤维素, 且顶部含量高于基部。在花托/果实发育过程中, 正调控基因GL1、 GL2、 TTG1、 PDF2和PDF2-like在整个发育过程中呈现相似的表达趋势, 其中GL1、 PDF2和PDF2-like在R1时期的表皮毛中表达量显著高于去毛花托/果实, 与表皮毛的早期形成相关; 负调控基因TRY和CPC在去毛花托/果实中的表达量均高于表皮毛中的表达量, 与表型一致。

关键词：无籽刺梨; 表皮毛; 形态结构; 基因表达

收稿：2020-10-22   修定：2021-01-04

资助：国家自然科学基金委员会-贵州省人民政府喀斯特科学研究中心项目(U1812401)、国家自然科学基金(31660459)、贵州省高层次 创新型人才培养计划(20164016)、贵州省生物学一流学科建设项目(GNYL[2017]009)

Morphological structure of trichomes on Rosa sterilis fruit and expression of associated genes during development

MA Wentao^1,2, LU Min¹, WANG Daojing¹, AN Huaming^1,2,*

¹Guizhou Engineering Research Center for Fruit Crops, Agricultural College, Guizhou University, Guiyang 550025, China; ²Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), Guiyang 550025, China

Corresponding author: AN Huaming; E-mail: hman@gzu.edu.cn

Abstract:

In this study, the different developmental stages of fruit in Rosa sterilis were used to observe the types, anatomical structures, and chemical compositions of trichomes. Moreover, the expression levels of genes involved in trichome development were also analyzed. The result indicated that the trichomes on the receptacle/fruit of R. sterilis were mainly flagelliform trichomes, acicular trichomes and capitate glandular trichomes with long stalk in the early stage. The flagelliform trichomes fell off with the fruits ripening, while the other two kinds of trichomes were lignifed to prickles. The acicular prickle on fruit was composed of cuticle layer, epidermal layer and parenchyma cells. The ultrastructure between glandular prickles and acicular prickles exhibited signifcant differences. Prickles of fruit mainly consisted of lignin, suberin, cellulose and hemicelluloses, whose content in upper tissue was higher than that in beneath tissue. The expression of positive regulatory genes GL1, GL2, TTG1, PDF2 and PDF2-like shared a similar expression trend, of which GL1, PDF2 and PDF2-like showed remarkably higher expression levels in trichomes compared to trichome-removed receptacle/fruit at R1 stage, associating with trichome formation in the early stage. The transcript levels of the negative regulatory genes TRY and CPC were higher in trichome-removed receptacle/fruit than those in trichomes during the development of fruit, which was consistent with phenotype.

Key words: Rosa sterilis; trichome; morphological structure; gene expression