Relationship between seasonal progression of floral meristem development and FLOWERING LOCUS T expression in the deciduous tree Fagus crenata
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Estimating the timing of flower bud formation in plants is essential to identify environmental factors that regulate floral transition. The presence of winter dormancy between the initiation of flowers and anthesis, characteristic of most trees in the temperate forests, hampers accurate estimation of the timing of floral transition. To overcome this difficulty, expression levels of flowering-time genes could be used as indicators of the timing of floral transition. Here, we evaluated the usefulness of molecular markers in estimating the timing of floral transition in Fagus crenata, a deciduous tree that shows intermittent and synchronized flowering at the population level. We selected FLOWERING LOCUS T (FT) as a candidate molecular marker and quantified the expression levels of its ortholog in F. crenata (FcFT). Subsequently, we analyzed the relationship between morphogenetic changes that occur between the vegetative state of the buds and the initiation of floral organs, and compared the FcFT expression levels in reproductive and vegetative buds, collected from spring to autumn. FcFT expression in leaves peaked at least two weeks before the morphological changes associated with flowering were visible in the buds in late July. FcFT expression levels were significantly higher in the reproductive buds than in the vegetative buds in July. These results suggest that the FcFT expression in July is a reliable indicator of the timing and occurrence of floral transition. This study highlights the utility of molecular tools in unraveling reproductive dynamics in plants, in combination with ecological and physiological approaches.
KeywordsDevelopment Flowering Gene expression Masting Shoot apical meristem
We thank Hokkaido Research Center of Forestry and Forest Products Research Institute for permission to use their facilities, Y. Sano for advice in embedding samples, Y. Saburi and Y. Mori for their laboratory assistance, K. Kitamura for field assistance, and MJ Kobayashi for comments for manuscript. This study was funded by the Program to Disseminate Tenure Tracking System, MEXT, Japan (grant to YM) and JSPS KAKENHI (Grant Number 26251042 to AS).
- Bustin SA, Benes V, Garson JA, Hellemans J, Huggett J, Kubista M, Nuller R, Nolan T, Pfaffl MW, Shipley GL, Vandesompele J, Wittwer CT (2009) The MIQE guidelines: minimum information for publication of quantitative real-time PCR experiments. Clin Chem 55:611–622. doi: 10.1373/clinchem.2008.112797 CrossRefPubMedGoogle Scholar
- Fornara F, de Montaigu A, Coupland G (2010) SnapShot: control of flowering in Arabidopsis thaliana. Cell 141:550, 550 e1–550 e2. doi: 10.1016/j.cell.2010.04.024
- Hokkaido Research Center FFPRI (2013) Meteorological data at the Hokkaido Research Center, Forestry and Forest Products Research Institute, Sapporo, Japan. Available upon request at http://www.ffpri.affrc.go.jp/hkd/en/index.html
- Miyazaki Y, Maruyama Y, Chiba Y, Kobayashi MJ, Joseph B, Shimizu KK, Mochida K, Hiura T, Kon H, Satake A (2014) Nitrogen as a key regulator of flowering in Fagus crenata: understanding the physiological mechanism of masting by gene expression analysis. Ecol Lett 17:1299–1309. doi: 10.1111/ele.12338 CrossRefPubMedGoogle Scholar