Molecular identification and functional verification of SPL9 and SPL15 of Lilium

• Published in: Molecular genetics and genomics : MGG 2022, Vol.297 (1), p.63-74
• Main Authors: Zhao, Mengna, Liu, Rongxiu, Chen, Yao, Cui, Jinteng, Ge, Wei, Zhang, Kezhong
• Format: Article
• Language: English
• Subjects: Animal Genetics and Genomics; Arabidopsis - genetics; Arabidopsis - growth & development; Biochemistry; Biomedical and Life Sciences; Cell walls; Flowers; Flowers - genetics; Flowers - metabolism; Gene Expression Regulation, Developmental - genetics; Gene Expression Regulation, Plant; Genes, Plant - physiology; Genetic transformation; Homology; Human Genetics; Hybridization; Juveniles; Life Sciences; Lilium; Lilium - classification; Lilium - genetics; Localization; Microbial Genetics and Genomics; Nicotiana - genetics; Nicotiana - growth & development; Original Article; Phase transitions; Phenotype; Phylogeny; Plant Development; Plant Genetics and Genomics; Plant Proteins - genetics; Plant Proteins - physiology; Plant Roots - genetics; Plants, Genetically Modified; Starch grains; Transcription activation; Transcription factors; Transcription Factors - genetics; Transcription Factors - physiology; Transgenic plants; Transmission electron microscopy
• ISSN: 1617-4615; 1617-4623; 1617-4623
• DOI: 10.1007/s00438-021-01832-8

The transformation of plants from juveniles to adults is a key process in plant growth and development, and the main regulatory factors are miR156 and SQUAMOSA promoter binding protein-like (SPL) transcription factors. Lilium is an ornamental bulb, but it has a long maturation time. In this experiment, Lilium bulbs were subjected to a temperature treatment of 15 °C for 4 weeks to initiate vegetative phase change. Transmission electron microscopy indicated the cell wall of bud core tissue undergoing vegetative phase change became thinner, the starch grains were reduced, and the growth of the juvenile stage was accelerated. The key transcription factors LbrSPL9 and LbrSPL15 were cloned, and the phylogenetic analysis showed they possessed high homology with other plant SPLs. Subcellular localization and transcription activation experiments confirmed LbrSPL9 and LbrSPL15 were mainly located in the nucleus and exhibited transcriptional activity. The results of in situ hybridization showed the expression levels of LbrSPL9 and LbrSPL1 5 were increased after temperature change treatment. The functional verification experiment of the transgenic plants confirmed that the overexpression of LbrSPL9 and LbrSPL15 could shorten maturation time. These findings help elucidate the regulatory mechanisms of phase transition in Lilium and provide a reference for breeding research in other bulbous flowers.