Transcriptome-wide analysis to dissect the transcription factors orchestrating the phase change from vegetative to reproductive development in Larix kaempferi

作   者：Xiang Wei-Bo, Li Wan-Feng, Zhang Shou-Gong, Qi Li-Wang
期刊名称：Tree Genetics & Genomes
影响因子：1.862
卷 期 号：15
页     码：68
关键词：Larch, Phase change, Transcriptome, Transcription factor, MADS
论文摘要：
The timing of phase change from vegetative to reproductive development during aging of forest trees is important for wood and seed production. In a previous study, we investigated the effects of aging on wood formation by measuring the transcriptomic changes in the uppermost main stems of 1-, 2-, 5-, 10-, 25-, and 50-year-old Larix kaempferi. Based on the published transcriptome data, here we investigated the transcriptomic differences between the juvenile vegetative (1- and 2-year-old) and adult reproductive (25- and 50-year-old) phases to determine the molecular mechanisms underlying the phase change. In total, 12,789 transcripts were identified as differentially expressed genes, including 573 transcription factors. Further analysis showed that 27 transcription factors belonging to 8 families were common to all four comparisons between old and young life stage categories: (I) 25 vs 1 year old; (II) 50 vs 1 year old; (III) 25 vs 2 years old; and (IV) 50 vs 2 years old. The analysis of their expression patterns in six age categories showed that members of the AP2 and Dof families were expressed highly in 1- and 2-year-old trees, weakly in 25- and 50-year-old trees, while members of the C3H, G2-like, GRAS, MYB-related, and MADS families had the opposite patterns. Notably, one member of the MADS family was only detected in 25- and 50-year-old trees. These results suggest that the phase change might (1) occur in the early stage of the L. kaempferi lifetime and (2) be controlled by a complex regulatory network of different transcription factors, some of which are known to play roles in the phase change in model plants. These findings not only provide molecular markers to distinguish different stages of tree growth and development and potential targets for genetic manipulation to improve the reproductive traits of trees, but also improve our understanding of the phase change with aging in trees.