Roles of the GA-mediated SPL Gene Family and miR156 in the Floral Development of Chinese Chestnut (Castanea mollissima)

International Journal of Molecular Sciences

Guosong Chen¹  Yu Xing¹  Jingtong Li¹  Ling Qin¹  Yang Liu¹  Yuerong Gao¹  Kefeng Fang²  Qingqin Cao³  Qing Zhang⁴ 

[1] Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing University of Agriculture, Beijing 102206, China;Beijing Collaborative Innovation Center for Eco-environmental Improvement with Forestry and Fruit Trees, Beijing 102206, China;College of Biological Science and Engineering, Key Laboratory of Urban Agriculture (North China), Ministry of Agriculture, Beijing 102206, China;College of Plant Science and Technology, Beijing Key Laboratory for Agricultural Application and New Technique, Beijing University of Agriculture, Beijing 102206, China;

关键词: Castanea mollissima;    miR156;    SPL gene family;    GA;    floral development;    expression patterns;   

DOI  :  10.3390/ijms20071577

来源: DOAJ

【 摘 要 】

Chestnut (Castanea mollissima) is a deciduous tree species with major economic and ecological value that is widely used in the study of floral development in woody plants due its monoecious and out-of-proportion characteristics. Squamosa promoter-binding protein-like (SPL) is a plant-specific transcription factor that plays an important role in floral development. In this study, a total of 18 SPL genes were identified in the chestnut genome, of which 10 SPL genes have complementary regions of CmmiR156. An analysis of the phylogenetic tree of the squamosa promoter-binding protein (SBP) domains of the SPL genes of Arabidopsis thaliana, Populus trichocarpa, and C. mollissima divided these SPL genes into eight groups. The evolutionary relationship between poplar and chestnut in the same group was similar. A structural analysis of the protein-coding regions (CDSs) showed that the domains have the main function of SBP domains and that other domains also play an important role in determining gene function. The expression patterns of CmmiR156 and CmSPLs in different floral organs of chestnut were analyzed by real-time quantitative PCR. Some CmSPLs with similar structural patterns showed similar expression patterns, indicating that the gene structures determine the synergy of the gene functions. The application of gibberellin (GA) and its inhibitor (Paclobutrazol, PP₃₃₃) to chestnut trees revealed that these exert a significant effect on the number and length of the male and female chestnut flowers. GA treatment significantly increased CmmiR156 expression and thus significantly decreased the expression of its target gene, CmSPL6/CmSPL9/CmSPL16, during floral bud development. This finding indicates that GA might indirectly affect the expression of some of the SPL target genes through miR156. In addition, RNA ligase-mediated rapid amplification of the 5′ cDNA ends (RLM-RACE) experiments revealed that CmmiR156 cleaves CmSPL9 and CmSPL16 at the 10th and 12th bases of the complementary region. These results laid an important foundation for further study of the biological function of CmSPLs in the floral development of C. mollissima.

【 授权许可】

Unknown