Zhao Zhongnan, Zheng Tangchun, Dai Lijuan, Liu Yi, Li Shuang, Qu Guanzheng
State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, China.
National Engineering Research Center for Floriculture, School of Landscape Architecture, Beijing Forestry University, Beijing, China.
Front Plant Sci. 2022 Apr 7;13:868731. doi: 10.3389/fpls.2022.868731. eCollection 2022.
The D-type cyclin (CYCD) gene, as the rate-limiting enzyme in the G1 phase of cell cycle, plays a vital role in the process of plant growth and development. Early studies on plant cyclin mostly focused on herbs, such as . The sustainable growth ability of woody plants is a unique characteristic in the study of plant cyclin. Here, the promoter of was cloned from poplar by PCR and genetically transformed into tobacco. A strong GUS activity was observed in the areas with vigorous cell division, such as stem tips, lateral buds, and young leaves. The fusion expression vector was transformed into tobacco, and the green fluorescence signal was observed in the nucleus. Compared with the control plant, the transgenic tobacco showed significant changes in the flower organs, such as enlargement of sepals, petals, and fruits. Furthermore, the stems of transgenic plants were slightly curved at each stem node, the leaves were curled on the adaxial side, and the fruits were seriously aborted after artificial pollination. Microscopic observation showed that the epidermal cells of petals, leaves, and seed coats of transgenic plants became smaller. The transcriptional levels of endogenous genes, such as , , , and , were upregulated by . Therefore, gene played an important role in the regulation of flower organ and stem development, providing new understanding for the functional characterization of gene and new resources for improving the ornamental value of horticultural plants.
D型细胞周期蛋白（CYCD）基因作为细胞周期G1期的限速酶，在植物生长发育过程中起着至关重要的作用。早期对植物细胞周期蛋白的研究大多集中在草本植物上，如 。木本植物的可持续生长能力是植物细胞周期蛋白研究中的一个独特特征。在此，通过PCR从杨树中克隆了 的启动子，并将其遗传转化到烟草中。在茎尖、侧芽和幼叶等细胞分裂旺盛的区域观察到较强的GUS活性。将 融合表达载体转化到烟草中，在细胞核中观察到绿色荧光信号。与对照植株相比，转基因烟草的花器官出现了显著变化，如萼片、花瓣和果实增大。此外，转基因植株的茎在每个茎节处略有弯曲，叶片在近轴侧卷曲，人工授粉后果实严重败育。显微镜观察表明，转基因植株花瓣、叶片和种皮的表皮细胞变小。 、 、 和 等内源基因的转录水平被 上调。因此， 基因在花器官和茎发育的调控中发挥了重要作用，为 基因的功能表征提供了新的认识，也为提高园艺植物观赏价值提供了新资源。
