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Integrated transcriptome sequencing and dynamic analysis reveal carbon source partitioning between terpenoid and oil accumulation in developing Lindera glauca fruits.

Niu J, Chen Y, An J, Hou X, Cai J, Wang J, Zhang Z, Lin S - Sci Rep (2015)

Bottom Line: The resulting 3 crucial samples at 50, 125 and 150 days after flowering (DAF) were selected for comparative deep transcriptome analysis.Integrated differential expression profiling and qRT-PCR, we specifically characterize the key enzymes and transcription factors (TFs) involved in regulating carbon allocation ratios for terpenoid or oil accumulation in developing LGF.These results contribute to our understanding of the regulatory mechanisms of carbon source partitioning between terpenoid and oil in developing LGF, and to the improvement of resource utilization and molecular breeding for L. glauca.

View Article: PubMed Central - PubMed

Affiliation: College of Biological Sciences and Biotechnology, College of Nature Conservation, National Engineering Laboratory for Tree Breeding, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, Beijing Forestry University, Beijing 10083, China.

ABSTRACT
Lindera glauca fruits (LGF) with the abundance of terpenoid and oil has emerged as a novel specific material for industrial and medicinal application in China, but the complex regulatory mechanisms of carbon source partitioning into terpenoid biosynthetic pathway (TBP) and oil biosynthetic pathway (OBP) in developing LGF is still unknown. Here we perform the analysis of contents and compositions of terpenoid and oil from 7 stages of developing LGF to characterize a dramatic difference in temporal accumulative patterns. The resulting 3 crucial samples at 50, 125 and 150 days after flowering (DAF) were selected for comparative deep transcriptome analysis. By Illumina sequencing, the obtained approximately 81 million reads are assembled into 69,160 unigenes, among which 174, 71, 81 and 155 unigenes are implicated in glycolysis, pentose phosphate pathway (PPP), TBP and OBP, respectively. Integrated differential expression profiling and qRT-PCR, we specifically characterize the key enzymes and transcription factors (TFs) involved in regulating carbon allocation ratios for terpenoid or oil accumulation in developing LGF. These results contribute to our understanding of the regulatory mechanisms of carbon source partitioning between terpenoid and oil in developing LGF, and to the improvement of resource utilization and molecular breeding for L. glauca.

No MeSH data available.


The transcriptional levels for the enzymes involved in the generation of G3P and acetyl-CoA.
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f4: The transcriptional levels for the enzymes involved in the generation of G3P and acetyl-CoA.

Mentions: Sucrose is known as the most source of carbon required for terpenoid and oil biosynthesis in plants. To deeply understand the allocation of available carbon source for terpenoid and oil biosynthesis in developing LGF, the differential expression profiles of genes for key enzymes, providing the precursors for TBP and OBP, were concretely analyzed (Supplementary Tables S5, S6 and S7). We identified 2 unigenes for two SuSy isozymes with differential profiles (down in SuSy1 and up in SuSy2) in developing LGF, but their expression levels were higher than those for two SUC isozymes (SUC1 and 2) with stable expression (Fig. 4), indicating that SuSy, as an important sucrose-cleaving enzyme, play a fundamental role in the supply of hexoses for the terpenoid and oil biosynthetic demand in developing LGF. Indeed, our qRT-PCR analysis attested the fact that SuSy1 expression with a gradual decrease was observed in 7 developing stages of LGF, while SuSy2 was gradually up-regulated (Supplementary Fig. S5). This striking difference of transcript level between two SuSy isozymes was entirely consistent with the different accumulative patterns of terpenoid and oil in developing LGF (Fig. 1), indicating that the expressions of SuSy1 and 2 specifically responded to carbohydrate availability for terpenoid and oil biosynthesis in developing LGF. Additionally, we noticed the differential expression profiles of some crucial enzymes involved in carbon flux from the hexoses into TBP or OBP. Our data showed that the expressions of cytosolic PK and ACL, mitochondrial PDHC, plastidial TKL and TAL were all significantly up-regulated in early development of LGF, but a significant higher expression for plastidial PK and PDHC in middle-late development of LGF (Figs 4 and 5). These results revealed that a main hexose flux via cytosolic glycolysis or plastidial PPP is to provide acetyl-CoA or G3P respectively for terpenoid biosynthesis in early development of LGF, however a greater proportion of hexose to acetyl-CoA flux via plastidial glycolysis is required for oil biosynthesis in middle-late development of LGF. It was interesting to note that the genes encoding ribulose bisphosphate carboxylase (RBC), fixation of CO2 and ribulose 5-phosphate to 3-phospho-D-glycerate (3PGA)47, displayed significant higher expression at middle development of LGF (Supplementary Table S5). Combining with 3-fold higher expression of ENO in plastid than in cytosol (Supplementary Table S5), our findings indicated that Calvin pathway is crucial for the supplementation of carbon source for oil biosynthesis in middle development of LGF. Intriguingly, we also found that among the four glucolytic transporters (GLT, GPT, TPT and PPT), only both PPT and GPT showed a significant abundance of transcript in middle-late development of LGF (Fig. 4), as was in accordance with our qRT-PCR results that the expressions of PPT and GPT were up-regulated in 7 developing stages of LGF (Supplementary Fig. S5). Thus, a higher capacity of PPT and GPT provide glycolytic substrates (hexose phosphate, G6P and F6P) and intermediates (triose phosphate, PEP) from the cytosol to plastid for oil biosynthesis in developing LGF. Together, our data highlight that the partitioning of available carbon source (sucrose) is tightly regulated in response of LGF to different developing stages, leading to temporal allocation of sucrose flux to the important precursor (acetyl-CoA or G3P) required for TBP and OBP.


Integrated transcriptome sequencing and dynamic analysis reveal carbon source partitioning between terpenoid and oil accumulation in developing Lindera glauca fruits.

Niu J, Chen Y, An J, Hou X, Cai J, Wang J, Zhang Z, Lin S - Sci Rep (2015)

The transcriptional levels for the enzymes involved in the generation of G3P and acetyl-CoA.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4597268&req=5

f4: The transcriptional levels for the enzymes involved in the generation of G3P and acetyl-CoA.
Mentions: Sucrose is known as the most source of carbon required for terpenoid and oil biosynthesis in plants. To deeply understand the allocation of available carbon source for terpenoid and oil biosynthesis in developing LGF, the differential expression profiles of genes for key enzymes, providing the precursors for TBP and OBP, were concretely analyzed (Supplementary Tables S5, S6 and S7). We identified 2 unigenes for two SuSy isozymes with differential profiles (down in SuSy1 and up in SuSy2) in developing LGF, but their expression levels were higher than those for two SUC isozymes (SUC1 and 2) with stable expression (Fig. 4), indicating that SuSy, as an important sucrose-cleaving enzyme, play a fundamental role in the supply of hexoses for the terpenoid and oil biosynthetic demand in developing LGF. Indeed, our qRT-PCR analysis attested the fact that SuSy1 expression with a gradual decrease was observed in 7 developing stages of LGF, while SuSy2 was gradually up-regulated (Supplementary Fig. S5). This striking difference of transcript level between two SuSy isozymes was entirely consistent with the different accumulative patterns of terpenoid and oil in developing LGF (Fig. 1), indicating that the expressions of SuSy1 and 2 specifically responded to carbohydrate availability for terpenoid and oil biosynthesis in developing LGF. Additionally, we noticed the differential expression profiles of some crucial enzymes involved in carbon flux from the hexoses into TBP or OBP. Our data showed that the expressions of cytosolic PK and ACL, mitochondrial PDHC, plastidial TKL and TAL were all significantly up-regulated in early development of LGF, but a significant higher expression for plastidial PK and PDHC in middle-late development of LGF (Figs 4 and 5). These results revealed that a main hexose flux via cytosolic glycolysis or plastidial PPP is to provide acetyl-CoA or G3P respectively for terpenoid biosynthesis in early development of LGF, however a greater proportion of hexose to acetyl-CoA flux via plastidial glycolysis is required for oil biosynthesis in middle-late development of LGF. It was interesting to note that the genes encoding ribulose bisphosphate carboxylase (RBC), fixation of CO2 and ribulose 5-phosphate to 3-phospho-D-glycerate (3PGA)47, displayed significant higher expression at middle development of LGF (Supplementary Table S5). Combining with 3-fold higher expression of ENO in plastid than in cytosol (Supplementary Table S5), our findings indicated that Calvin pathway is crucial for the supplementation of carbon source for oil biosynthesis in middle development of LGF. Intriguingly, we also found that among the four glucolytic transporters (GLT, GPT, TPT and PPT), only both PPT and GPT showed a significant abundance of transcript in middle-late development of LGF (Fig. 4), as was in accordance with our qRT-PCR results that the expressions of PPT and GPT were up-regulated in 7 developing stages of LGF (Supplementary Fig. S5). Thus, a higher capacity of PPT and GPT provide glycolytic substrates (hexose phosphate, G6P and F6P) and intermediates (triose phosphate, PEP) from the cytosol to plastid for oil biosynthesis in developing LGF. Together, our data highlight that the partitioning of available carbon source (sucrose) is tightly regulated in response of LGF to different developing stages, leading to temporal allocation of sucrose flux to the important precursor (acetyl-CoA or G3P) required for TBP and OBP.

Bottom Line: The resulting 3 crucial samples at 50, 125 and 150 days after flowering (DAF) were selected for comparative deep transcriptome analysis.Integrated differential expression profiling and qRT-PCR, we specifically characterize the key enzymes and transcription factors (TFs) involved in regulating carbon allocation ratios for terpenoid or oil accumulation in developing LGF.These results contribute to our understanding of the regulatory mechanisms of carbon source partitioning between terpenoid and oil in developing LGF, and to the improvement of resource utilization and molecular breeding for L. glauca.

View Article: PubMed Central - PubMed

Affiliation: College of Biological Sciences and Biotechnology, College of Nature Conservation, National Engineering Laboratory for Tree Breeding, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, Beijing Forestry University, Beijing 10083, China.

ABSTRACT
Lindera glauca fruits (LGF) with the abundance of terpenoid and oil has emerged as a novel specific material for industrial and medicinal application in China, but the complex regulatory mechanisms of carbon source partitioning into terpenoid biosynthetic pathway (TBP) and oil biosynthetic pathway (OBP) in developing LGF is still unknown. Here we perform the analysis of contents and compositions of terpenoid and oil from 7 stages of developing LGF to characterize a dramatic difference in temporal accumulative patterns. The resulting 3 crucial samples at 50, 125 and 150 days after flowering (DAF) were selected for comparative deep transcriptome analysis. By Illumina sequencing, the obtained approximately 81 million reads are assembled into 69,160 unigenes, among which 174, 71, 81 and 155 unigenes are implicated in glycolysis, pentose phosphate pathway (PPP), TBP and OBP, respectively. Integrated differential expression profiling and qRT-PCR, we specifically characterize the key enzymes and transcription factors (TFs) involved in regulating carbon allocation ratios for terpenoid or oil accumulation in developing LGF. These results contribute to our understanding of the regulatory mechanisms of carbon source partitioning between terpenoid and oil in developing LGF, and to the improvement of resource utilization and molecular breeding for L. glauca.

No MeSH data available.