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Sucrose metabolism gene families and their biological functions.

Jiang SY, Chi YH, Wang JZ, Zhou JX, Cheng YS, Zhang BL, Ma A, Vanitha J, Ramachandran S - Sci Rep (2015)

Bottom Line: Although studies on general metabolism pathway were well documented, less information is available on the genome-wide identification of these genes, their expansion and evolutionary history as well as their biological functions.They were evolutionarily conserved under purifying selection among species and expression divergence played important roles for gene survival after expansion.Overexpression of 15 sorghum genes in Arabidopsis revealed their roles in biomass accumulation, flowering time control, seed germination and response to high salinity and sugar stresses.

View Article: PubMed Central - PubMed

Affiliation: Genome Structural Biology Group, Temasek Life Sciences Laboratory, National University of Singapore, Singapore 117604.

ABSTRACT
Sucrose, as the main product of photosynthesis, plays crucial roles in plant development. Although studies on general metabolism pathway were well documented, less information is available on the genome-wide identification of these genes, their expansion and evolutionary history as well as their biological functions. We focused on four sucrose metabolism related gene families including sucrose synthase, sucrose phosphate synthase, sucrose phosphate phosphatase and UDP-glucose pyrophosphorylase. These gene families exhibited different expansion and evolutionary history as their host genomes experienced differentiated rates of the whole genome duplication, tandem and segmental duplication, or mobile element mediated gene gain and loss. They were evolutionarily conserved under purifying selection among species and expression divergence played important roles for gene survival after expansion. However, we have detected recent positive selection during intra-species divergence. Overexpression of 15 sorghum genes in Arabidopsis revealed their roles in biomass accumulation, flowering time control, seed germination and response to high salinity and sugar stresses. Our studies uncovered the molecular mechanisms of gene expansion and evolution and also provided new insight into the role of positive selection in intra-species divergence. Overexpression data revealed novel biological functions of these genes in flowering time control and seed germination under normal and stress conditions.

No MeSH data available.


Related in: MedlinePlus

Overexpression of sweet sorghum SuSy genes in Arabidopsis.(A) A total of 5 sorghum SuSy genes were independently overexpressed in Arabidopsis under the maize ubiquitin promoter to generate at least 3 independent transgenic lines with single copy of T-DNA insertion in each construct. (B) An example of copy number detection by Southern blot hybridization. DNA samples were prepared from transgenic Arabidopsis plants overexpressing the sorghum gene Sobic.001G378300. Top and bottom panels show the results from DNA samples digested by PstI and SpeI, respectively. (C–F) GUS activities in transgenic plants carrying the Sobic.001G378300 promoter::GUS construct. (C) the whole Arabidopsis plants; (D) leaf; (E) root; (F) silique. (G) Expression analysis of transgenic plants overexpressing Sobic.001G378300. ACT1, an Arabidopsis gene encoding Actin-1 protein with locus name At2g37620. The prefix “Sobic.” was omitted in the locus name for convenience. (H) Investigation of fresh biomass of four independent transgenic plants with single copy of T-DNA insertion. Thirty-day plants grown on media were used for the survey. (I–K) Phenotypic observation of transgenic plants grown under different concentrations of sucrose, glucose and NaCl containing media, respectively.
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f6: Overexpression of sweet sorghum SuSy genes in Arabidopsis.(A) A total of 5 sorghum SuSy genes were independently overexpressed in Arabidopsis under the maize ubiquitin promoter to generate at least 3 independent transgenic lines with single copy of T-DNA insertion in each construct. (B) An example of copy number detection by Southern blot hybridization. DNA samples were prepared from transgenic Arabidopsis plants overexpressing the sorghum gene Sobic.001G378300. Top and bottom panels show the results from DNA samples digested by PstI and SpeI, respectively. (C–F) GUS activities in transgenic plants carrying the Sobic.001G378300 promoter::GUS construct. (C) the whole Arabidopsis plants; (D) leaf; (E) root; (F) silique. (G) Expression analysis of transgenic plants overexpressing Sobic.001G378300. ACT1, an Arabidopsis gene encoding Actin-1 protein with locus name At2g37620. The prefix “Sobic.” was omitted in the locus name for convenience. (H) Investigation of fresh biomass of four independent transgenic plants with single copy of T-DNA insertion. Thirty-day plants grown on media were used for the survey. (I–K) Phenotypic observation of transgenic plants grown under different concentrations of sucrose, glucose and NaCl containing media, respectively.

Mentions: To understand the biological functions of genes encoding these four gene families, we overexpressed these genes under the maize ubiquitin promoter in Arabidopsis. For the SuSy family, all the coding regions of 5 genes were isolated from the sweet sorghum Keller by RT-PCR and subcloned into the binary vector pCambio1300 for Agrobacterium-mediated transformation. A total of 17 to 19 independent transgenic T1 plants were propagated from T0 generation (Fig. 6A) based on Southern blot hybridization (Fig. 6B). At least 3 independent T2 plants with single T-DNA insertion were selected for further investigation (Fig. 6A,B). Our data showed that no visible phenotypic difference was observed between wild type (WT) Arabidopsis and overexpression transgenic plants. Here we further characterized the sorghum gene Sobic.001G378300 by investigating its promoter activities and the effects of overexpressing this gene in Arabidopsis. We first analyzed its promoter activities in the promoter::GUS transgenic plants. Around 2 Kb of the promoter region upstream of the start codon of this gene was fused with the GUS reporter gene and was then delivered into the Arabidopsis genome. The GUS staining results showed that the activities of the promoter could be observed in the whole plants (Fig. 6C) including leaves (Fig. 6D), roots (Fig. 6E) and siliques (Fig. 6F). Further observation showed that the gene showed higher expression level in the phloem tissue of nodes and veins (Fig. 6C,D). We then characterized the transgenic Arabidopsis lines by overexpressing this gene. A total of 5 independent lines were subjected to expression analysis, which showed that the gene was highly expressed in these transgenic plants (Fig. 6G). However, these transgenic lines showed no statistical difference in their biomass yield (Fig. 6H). We also did not observe the difference in brix degree. We then subjected these lines into stress treatments. Under 1-7% sucrose stress, both transgenic plants and WT showed no obvious difference (Fig. 6I). Similarly, no difference was observed under both glucose and NaCl treatments (Fig. 6J,K). In general, no morphological phenotype was observed under normal or stress conditions after overexpression of the gene Sobic.001G378300.


Sucrose metabolism gene families and their biological functions.

Jiang SY, Chi YH, Wang JZ, Zhou JX, Cheng YS, Zhang BL, Ma A, Vanitha J, Ramachandran S - Sci Rep (2015)

Overexpression of sweet sorghum SuSy genes in Arabidopsis.(A) A total of 5 sorghum SuSy genes were independently overexpressed in Arabidopsis under the maize ubiquitin promoter to generate at least 3 independent transgenic lines with single copy of T-DNA insertion in each construct. (B) An example of copy number detection by Southern blot hybridization. DNA samples were prepared from transgenic Arabidopsis plants overexpressing the sorghum gene Sobic.001G378300. Top and bottom panels show the results from DNA samples digested by PstI and SpeI, respectively. (C–F) GUS activities in transgenic plants carrying the Sobic.001G378300 promoter::GUS construct. (C) the whole Arabidopsis plants; (D) leaf; (E) root; (F) silique. (G) Expression analysis of transgenic plants overexpressing Sobic.001G378300. ACT1, an Arabidopsis gene encoding Actin-1 protein with locus name At2g37620. The prefix “Sobic.” was omitted in the locus name for convenience. (H) Investigation of fresh biomass of four independent transgenic plants with single copy of T-DNA insertion. Thirty-day plants grown on media were used for the survey. (I–K) Phenotypic observation of transgenic plants grown under different concentrations of sucrose, glucose and NaCl containing media, respectively.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4663468&req=5

f6: Overexpression of sweet sorghum SuSy genes in Arabidopsis.(A) A total of 5 sorghum SuSy genes were independently overexpressed in Arabidopsis under the maize ubiquitin promoter to generate at least 3 independent transgenic lines with single copy of T-DNA insertion in each construct. (B) An example of copy number detection by Southern blot hybridization. DNA samples were prepared from transgenic Arabidopsis plants overexpressing the sorghum gene Sobic.001G378300. Top and bottom panels show the results from DNA samples digested by PstI and SpeI, respectively. (C–F) GUS activities in transgenic plants carrying the Sobic.001G378300 promoter::GUS construct. (C) the whole Arabidopsis plants; (D) leaf; (E) root; (F) silique. (G) Expression analysis of transgenic plants overexpressing Sobic.001G378300. ACT1, an Arabidopsis gene encoding Actin-1 protein with locus name At2g37620. The prefix “Sobic.” was omitted in the locus name for convenience. (H) Investigation of fresh biomass of four independent transgenic plants with single copy of T-DNA insertion. Thirty-day plants grown on media were used for the survey. (I–K) Phenotypic observation of transgenic plants grown under different concentrations of sucrose, glucose and NaCl containing media, respectively.
Mentions: To understand the biological functions of genes encoding these four gene families, we overexpressed these genes under the maize ubiquitin promoter in Arabidopsis. For the SuSy family, all the coding regions of 5 genes were isolated from the sweet sorghum Keller by RT-PCR and subcloned into the binary vector pCambio1300 for Agrobacterium-mediated transformation. A total of 17 to 19 independent transgenic T1 plants were propagated from T0 generation (Fig. 6A) based on Southern blot hybridization (Fig. 6B). At least 3 independent T2 plants with single T-DNA insertion were selected for further investigation (Fig. 6A,B). Our data showed that no visible phenotypic difference was observed between wild type (WT) Arabidopsis and overexpression transgenic plants. Here we further characterized the sorghum gene Sobic.001G378300 by investigating its promoter activities and the effects of overexpressing this gene in Arabidopsis. We first analyzed its promoter activities in the promoter::GUS transgenic plants. Around 2 Kb of the promoter region upstream of the start codon of this gene was fused with the GUS reporter gene and was then delivered into the Arabidopsis genome. The GUS staining results showed that the activities of the promoter could be observed in the whole plants (Fig. 6C) including leaves (Fig. 6D), roots (Fig. 6E) and siliques (Fig. 6F). Further observation showed that the gene showed higher expression level in the phloem tissue of nodes and veins (Fig. 6C,D). We then characterized the transgenic Arabidopsis lines by overexpressing this gene. A total of 5 independent lines were subjected to expression analysis, which showed that the gene was highly expressed in these transgenic plants (Fig. 6G). However, these transgenic lines showed no statistical difference in their biomass yield (Fig. 6H). We also did not observe the difference in brix degree. We then subjected these lines into stress treatments. Under 1-7% sucrose stress, both transgenic plants and WT showed no obvious difference (Fig. 6I). Similarly, no difference was observed under both glucose and NaCl treatments (Fig. 6J,K). In general, no morphological phenotype was observed under normal or stress conditions after overexpression of the gene Sobic.001G378300.

Bottom Line: Although studies on general metabolism pathway were well documented, less information is available on the genome-wide identification of these genes, their expansion and evolutionary history as well as their biological functions.They were evolutionarily conserved under purifying selection among species and expression divergence played important roles for gene survival after expansion.Overexpression of 15 sorghum genes in Arabidopsis revealed their roles in biomass accumulation, flowering time control, seed germination and response to high salinity and sugar stresses.

View Article: PubMed Central - PubMed

Affiliation: Genome Structural Biology Group, Temasek Life Sciences Laboratory, National University of Singapore, Singapore 117604.

ABSTRACT
Sucrose, as the main product of photosynthesis, plays crucial roles in plant development. Although studies on general metabolism pathway were well documented, less information is available on the genome-wide identification of these genes, their expansion and evolutionary history as well as their biological functions. We focused on four sucrose metabolism related gene families including sucrose synthase, sucrose phosphate synthase, sucrose phosphate phosphatase and UDP-glucose pyrophosphorylase. These gene families exhibited different expansion and evolutionary history as their host genomes experienced differentiated rates of the whole genome duplication, tandem and segmental duplication, or mobile element mediated gene gain and loss. They were evolutionarily conserved under purifying selection among species and expression divergence played important roles for gene survival after expansion. However, we have detected recent positive selection during intra-species divergence. Overexpression of 15 sorghum genes in Arabidopsis revealed their roles in biomass accumulation, flowering time control, seed germination and response to high salinity and sugar stresses. Our studies uncovered the molecular mechanisms of gene expansion and evolution and also provided new insight into the role of positive selection in intra-species divergence. Overexpression data revealed novel biological functions of these genes in flowering time control and seed germination under normal and stress conditions.

No MeSH data available.


Related in: MedlinePlus