Limits...
Molecular dissection of pathway components unravel atisine biosynthesis in a non-toxic Aconitum species, A. heterophyllum Wall

View Article: PubMed Central - PubMed

ABSTRACT

Aconitum heterophyllum is an important component for various herbal drug formulations due to the occurrence of non-toxic aconites including marker compound, atisine. Despite huge pharmacological potential, the reprogramming of aconites production is limited due to lack of understanding on their biosynthesis. To address this problem, we have proposed here the complete atisine biosynthetic pathway for the first time connecting glycolysis, MVA/MEP, serine biosynthesis and diterpene biosynthetic pathways. The transcript profiling revealed phosphorylated pathway as a major contributor towards serine production in addition to repertoire of genes in glycolysis (G6PI, PFK, ALD and ENO), serine biosynthesis (PGDH and PSAT) and diterpene biosynthesis (KO and KH) sharing a similar pattern of expression (2-4-folds) in roots compared to shoots vis-à-vis atisine content (0–0.37 %). Quantification of steviol and comparative analysis of shortlisted genes between roots of high (0.37 %) vs low (0.14 %) atisine content accessions further confirmed the route of atisine biosynthesis. The results showed 6-fold increase in steviol content and 3–62-fold up-regulation of all the selected genes in roots of high content accession ascertaining their association towards atisine production. Moreover, significant positive correlations were observed between selected genes suggesting their co-expression and crucial role in atisine biosynthesis. This study, thus, offers unprecedented opportunities to explore the selected candidate genes for enhanced production of atisine in cultivated plant cells.

Electronic supplementary material: The online version of this article (doi:10.1007/s13205-016-0417-7) contains supplementary material, which is available to authorized users.

No MeSH data available.


Related in: MedlinePlus

Quantitative expression analysis of shortlisted genes in roots of high vs low content accessions of A. heterophyllum. The vertical axis represents the normalized expression and horizontal axis represents the different genes. Expression level was normalized to housekeeping genes, i.e., 26S and GAPDH. Bar graphs show mean ± SD (n = 4). Significance was evaluated for each gene between different accessions (****p < 0.0001). Abbreviations are elaborated in supplementary Table 4
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4835424&req=5

Fig4: Quantitative expression analysis of shortlisted genes in roots of high vs low content accessions of A. heterophyllum. The vertical axis represents the normalized expression and horizontal axis represents the different genes. Expression level was normalized to housekeeping genes, i.e., 26S and GAPDH. Bar graphs show mean ± SD (n = 4). Significance was evaluated for each gene between different accessions (****p < 0.0001). Abbreviations are elaborated in supplementary Table 4

Mentions: It is likely that the higher expression observed for these genes in initial screening might not only be due to variation in atisine content but also attributed to different tissues and differential production of other secondary metabolites. Therefore, to further ascertain the involvement of selected transcripts in atisine biosynthesis, the expression levels were checked on roots of high content accession (AHSR) and low content accession (AHKR) varying in atisine content with 0.37 and 0.14 %, respectively. This analyses revealed a striking increase in transcript level of G6PI, PFK, ALD, ENO, PGDH, PSAT, KO and KH enzymes in roots of high content accession to the tune of 18.26- (p < 0.0001), 11.54- (p < 0.0001), 62.36- (p < 0.0001), 8.51- (p < 0.0001), 11.44- (p < 0.0001), 17.15- (p < 0.0001), 3.37- (p < 0.0001) and 8.97-fold (p < 0.0001), respectively, compared to low content accession (Fig. 4). This shortlisting, thus, reflected the involvement of selected genes in the regulation of atisine biosynthesis in A. heterophyllum.Fig. 4


Molecular dissection of pathway components unravel atisine biosynthesis in a non-toxic Aconitum species, A. heterophyllum Wall
Quantitative expression analysis of shortlisted genes in roots of high vs low content accessions of A. heterophyllum. The vertical axis represents the normalized expression and horizontal axis represents the different genes. Expression level was normalized to housekeeping genes, i.e., 26S and GAPDH. Bar graphs show mean ± SD (n = 4). Significance was evaluated for each gene between different accessions (****p < 0.0001). Abbreviations are elaborated in supplementary Table 4
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4835424&req=5

Fig4: Quantitative expression analysis of shortlisted genes in roots of high vs low content accessions of A. heterophyllum. The vertical axis represents the normalized expression and horizontal axis represents the different genes. Expression level was normalized to housekeeping genes, i.e., 26S and GAPDH. Bar graphs show mean ± SD (n = 4). Significance was evaluated for each gene between different accessions (****p < 0.0001). Abbreviations are elaborated in supplementary Table 4
Mentions: It is likely that the higher expression observed for these genes in initial screening might not only be due to variation in atisine content but also attributed to different tissues and differential production of other secondary metabolites. Therefore, to further ascertain the involvement of selected transcripts in atisine biosynthesis, the expression levels were checked on roots of high content accession (AHSR) and low content accession (AHKR) varying in atisine content with 0.37 and 0.14 %, respectively. This analyses revealed a striking increase in transcript level of G6PI, PFK, ALD, ENO, PGDH, PSAT, KO and KH enzymes in roots of high content accession to the tune of 18.26- (p < 0.0001), 11.54- (p < 0.0001), 62.36- (p < 0.0001), 8.51- (p < 0.0001), 11.44- (p < 0.0001), 17.15- (p < 0.0001), 3.37- (p < 0.0001) and 8.97-fold (p < 0.0001), respectively, compared to low content accession (Fig. 4). This shortlisting, thus, reflected the involvement of selected genes in the regulation of atisine biosynthesis in A. heterophyllum.Fig. 4

View Article: PubMed Central - PubMed

ABSTRACT

Aconitum heterophyllum is an important component for various herbal drug formulations due to the occurrence of non-toxic aconites including marker compound, atisine. Despite huge pharmacological potential, the reprogramming of aconites production is limited due to lack of understanding on their biosynthesis. To address this problem, we have proposed here the complete atisine biosynthetic pathway for the first time connecting glycolysis, MVA/MEP, serine biosynthesis and diterpene biosynthetic pathways. The transcript profiling revealed phosphorylated pathway as a major contributor towards serine production in addition to repertoire of genes in glycolysis (G6PI, PFK, ALD and ENO), serine biosynthesis (PGDH and PSAT) and diterpene biosynthesis (KO and KH) sharing a similar pattern of expression (2-4-folds) in roots compared to shoots vis-&agrave;-vis atisine content (0&ndash;0.37&nbsp;%). Quantification of steviol and comparative analysis of shortlisted genes between roots of high (0.37&nbsp;%) vs low (0.14&nbsp;%) atisine content accessions further confirmed the route of atisine biosynthesis. The results showed 6-fold increase in steviol content and 3&ndash;62-fold up-regulation of all the selected genes in roots of high content accession ascertaining their association towards atisine production. Moreover, significant positive correlations were observed between selected genes suggesting their co-expression and crucial role in atisine biosynthesis. This study, thus, offers unprecedented opportunities to explore the selected candidate genes for enhanced production of atisine in cultivated plant cells.

Electronic supplementary material: The online version of this article (doi:10.1007/s13205-016-0417-7) contains supplementary material, which is available to authorized users.

No MeSH data available.


Related in: MedlinePlus