Functional analysis of alternative splicing of the FLOWERING LOCUS T orthologous gene in Chrysanthemum morifolium. (23rd November 2016)

• Record Type: Journal Article
• Authors: Mao, Yachao; Sun, Jing; Cao, Peipei; Zhang, Rong; Fu, Qike; Chen, Sumei; Chen, Fadi; Jiang, Jiafu
• Is Part Of: Horticulture research. Volume 3(2016)
• Publication Date: 2016-11-23
• Subjects: Plant breeding -- Plant molecular biology; Horticulture -- Research -- Periodicals; 635.072
• DOI: 10.1038/hortres.2016.58
• Languages: English
• ISSNs: 2052-7276

Abstract

Abstract: As the junction of floral development pathways, the FLOWERING LOCUS T (FT) protein called 'florigen' plays an important role in the process of plant flowering through signal integration. We isolated four transcripts encoding different isoforms of a FT orthologous gene CmFTL1, from Chrysanthemum morifolium cultivar 'Jimba'. Sequence alignments suggested that the four transcripts are related to the intron 1. Expression analysis showed that four alternative splicing (AS) forms of CmFTL1 varied depending on the developmental stage of the flower. The functional complement experiment using an Arabidopsis mutant ft-10 revealed that the archetypal and AS forms of CmFTL1 had the function of complementing late flower phenotype in different levels. In addition, transgenic confirmation at transcript level showed CmFTL1 and CmFTL1ast coexist in the same tissue type at the same developmental stage, indicating a post-transcriptional modification of CmFTL1 in Arabidopsis . Moreover, ectopic expression of different AS forms in chrysanthemum resulted in the development of multiple altered phenotypes, varying degrees of early flowering. We found that an alternative splicing form ( CmFTL1-astE134) without the exon 2 lacked the ability causing the earlier flower phenotype. The evidence in this study indicates that complex alternative processing of CmFTL1 transcripts in C. morifolium may be associated with flowering regulation and hold some potential for biotechnical engineering to create early-flowering phenotypes in ornamental cultivars. Abstract : Plant development: Controlling flowering time in chrysanthemum Researchers in China have discovered that several alternative versions of a single gene regulate flowering time in chrysanthemum. When Jiafu Jiang's team at the Nanjing Agricultural University investigated the flowering gene FT in Chrysanthemum morifolium, they found that the RNA it encodes is processed into four different versions through a mechanism known as alternative splicing. To test the functions of these versions, the team introduced them into Arabidopsis plants lacking FT. These plants normally have delayed flowering, but three of the four FT versions reduced the delay. The team also engineered chrysanthemum plants with increased expression of the different versions and found that overexpression of the same three led to earlier flowering. These findings suggest that alternative splicing of FT may be an avenue for biotechnological engineering of flowering time in ornamental plants.