Limits...
Digital gene expression analysis of male and female bud transition in Metasequoia reveals high activity of MADS-box transcription factors and hormone-mediated sugar pathways.

Zhao Y, Liang H, Li L, Tang S, Han X, Wang C, Xia X, Yin W - Front Plant Sci (2015)

Bottom Line: In the current study, hormone-treated shoots found in female and male buds were used to identify candidate genes involved in reproductive bud transition in Metasequoia.These differentially expressed transcripts were associated with 243 KEGG pathways.Our results increase our understanding of the reproductive bud transition in gymnosperms.

View Article: PubMed Central - PubMed

Affiliation: National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Biotechnology, Beijing Forestry University Beijing, China.

ABSTRACT
Metasequoia glyptostroboides is a famous redwood tree of ecological and economic importance, and requires more than 20 years of juvenile-to-adult transition before producing female and male cones. Previously, we induced reproductive buds using a hormone solution in juvenile Metasequoia trees as young as 5-to-7 years old. In the current study, hormone-treated shoots found in female and male buds were used to identify candidate genes involved in reproductive bud transition in Metasequoia. Samples from hormone-treated cone reproductive shoots and naturally occurring non-cone setting shoots were analyzed using 24 digital gene expression (DGE) tag profiles using Illumina, generating a total of 69,520 putative transcripts. Next, 32 differentially and specifically expressed transcripts were determined using quantitative real-time polymerase chain reaction, including the upregulation of MADS-box transcription factors involved in male bud transition and flowering time control proteins involved in female bud transition. These differentially expressed transcripts were associated with 243 KEGG pathways. Among the significantly changed pathways, sugar pathways were mediated by hormone signals during the vegetative-to-reproductive phase transition, including glycolysis/gluconeogenesis and sucrose and starch metabolism pathways. Key enzymes were identified in these pathways, including alcohol dehydrogenase (NAD) and glutathione dehydrogenase for the glycolysis/gluconeogenesis pathway, and glucanphosphorylase for sucrose and starch metabolism pathways. Our results increase our understanding of the reproductive bud transition in gymnosperms. In addition, these studies on hormone-mediated sugar pathways increase our understanding of the relationship between sugar and hormone signaling during female and male bud initiation in Metasequoia.

No MeSH data available.


Related in: MedlinePlus

Heat map showing the relative expression level forMetasequoiaMADS-box genes in different stages during vegetative to reproductive phase transition based on DGE data analysis. The color scale (−1.5 to 1.5) represents the Z-score calculated by comparing Reads Per Kilobase of exon model per Million mapped reads (RPKM). Hierarchical clustering of genes and samples was shown in the dendrogram on the top and side of the heatmap using the complete linkage approach.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4478380&req=5

Figure 6: Heat map showing the relative expression level forMetasequoiaMADS-box genes in different stages during vegetative to reproductive phase transition based on DGE data analysis. The color scale (−1.5 to 1.5) represents the Z-score calculated by comparing Reads Per Kilobase of exon model per Million mapped reads (RPKM). Hierarchical clustering of genes and samples was shown in the dendrogram on the top and side of the heatmap using the complete linkage approach.

Mentions: Several studies on various plant species have shown that MADS-box genes control various aspects of development and reproductive processes including flower formation. Among the DE genes in our comparisons, genes involved in flower development were identified, including 22 MADS-box family genes with 10 putatively coding for AGL MADS-proteins, five MADS-box proteins GGM13, and seven MADS-box transcription factors. To examine the expression patterns of the 22 MADS-box candidate genes in all samples, we clustered the genes in a heat-map. We observed that the upregulated genes were found in the male and female buds compared to non-cone setting samples, such as isotig16705 and isotig16706 putatively coding for AGL19 (which are upregulated in female buds), and isotig07445 putatively coding for AGL24 (which is highly expressed in male buds) (Figure 6). This analysis provides expression conditions for proteins involved in the transition of vegetative growth to reproductive phase and floral induction. Phylogenetic relationship of MADS box genes from angiosperms and gymnosperms show homolog to the putative transcripts from Metasequoia PUTs (isotig33092, isotig32790, isotig16705, isotig16706, and isotig07445). These five genes belong to a subclass of a MADS box family called MIKC type (Supplementary Figure S2).


Digital gene expression analysis of male and female bud transition in Metasequoia reveals high activity of MADS-box transcription factors and hormone-mediated sugar pathways.

Zhao Y, Liang H, Li L, Tang S, Han X, Wang C, Xia X, Yin W - Front Plant Sci (2015)

Heat map showing the relative expression level forMetasequoiaMADS-box genes in different stages during vegetative to reproductive phase transition based on DGE data analysis. The color scale (−1.5 to 1.5) represents the Z-score calculated by comparing Reads Per Kilobase of exon model per Million mapped reads (RPKM). Hierarchical clustering of genes and samples was shown in the dendrogram on the top and side of the heatmap using the complete linkage approach.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4478380&req=5

Figure 6: Heat map showing the relative expression level forMetasequoiaMADS-box genes in different stages during vegetative to reproductive phase transition based on DGE data analysis. The color scale (−1.5 to 1.5) represents the Z-score calculated by comparing Reads Per Kilobase of exon model per Million mapped reads (RPKM). Hierarchical clustering of genes and samples was shown in the dendrogram on the top and side of the heatmap using the complete linkage approach.
Mentions: Several studies on various plant species have shown that MADS-box genes control various aspects of development and reproductive processes including flower formation. Among the DE genes in our comparisons, genes involved in flower development were identified, including 22 MADS-box family genes with 10 putatively coding for AGL MADS-proteins, five MADS-box proteins GGM13, and seven MADS-box transcription factors. To examine the expression patterns of the 22 MADS-box candidate genes in all samples, we clustered the genes in a heat-map. We observed that the upregulated genes were found in the male and female buds compared to non-cone setting samples, such as isotig16705 and isotig16706 putatively coding for AGL19 (which are upregulated in female buds), and isotig07445 putatively coding for AGL24 (which is highly expressed in male buds) (Figure 6). This analysis provides expression conditions for proteins involved in the transition of vegetative growth to reproductive phase and floral induction. Phylogenetic relationship of MADS box genes from angiosperms and gymnosperms show homolog to the putative transcripts from Metasequoia PUTs (isotig33092, isotig32790, isotig16705, isotig16706, and isotig07445). These five genes belong to a subclass of a MADS box family called MIKC type (Supplementary Figure S2).

Bottom Line: In the current study, hormone-treated shoots found in female and male buds were used to identify candidate genes involved in reproductive bud transition in Metasequoia.These differentially expressed transcripts were associated with 243 KEGG pathways.Our results increase our understanding of the reproductive bud transition in gymnosperms.

View Article: PubMed Central - PubMed

Affiliation: National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Biotechnology, Beijing Forestry University Beijing, China.

ABSTRACT
Metasequoia glyptostroboides is a famous redwood tree of ecological and economic importance, and requires more than 20 years of juvenile-to-adult transition before producing female and male cones. Previously, we induced reproductive buds using a hormone solution in juvenile Metasequoia trees as young as 5-to-7 years old. In the current study, hormone-treated shoots found in female and male buds were used to identify candidate genes involved in reproductive bud transition in Metasequoia. Samples from hormone-treated cone reproductive shoots and naturally occurring non-cone setting shoots were analyzed using 24 digital gene expression (DGE) tag profiles using Illumina, generating a total of 69,520 putative transcripts. Next, 32 differentially and specifically expressed transcripts were determined using quantitative real-time polymerase chain reaction, including the upregulation of MADS-box transcription factors involved in male bud transition and flowering time control proteins involved in female bud transition. These differentially expressed transcripts were associated with 243 KEGG pathways. Among the significantly changed pathways, sugar pathways were mediated by hormone signals during the vegetative-to-reproductive phase transition, including glycolysis/gluconeogenesis and sucrose and starch metabolism pathways. Key enzymes were identified in these pathways, including alcohol dehydrogenase (NAD) and glutathione dehydrogenase for the glycolysis/gluconeogenesis pathway, and glucanphosphorylase for sucrose and starch metabolism pathways. Our results increase our understanding of the reproductive bud transition in gymnosperms. In addition, these studies on hormone-mediated sugar pathways increase our understanding of the relationship between sugar and hormone signaling during female and male bud initiation in Metasequoia.

No MeSH data available.


Related in: MedlinePlus