Transcriptome sequencing of rhizome tissue of Sinopodophyllum hexandrum at two temperatures

Abstract

BackgroundSinopodophyllum hexandrum is an endangered medicinal herb, which is commonly present in elevations ranging between 2,400–4,500 m and is sensitive to temperature. Medicinal property of the species is attributed to the presence of podophyllotoxin in the rhizome tissue. The present work analyzed transcriptome of rhizome tissue of S. hexandrum exposed to 15°C and 25°C to understand the temperature mediated molecular responses including those associated with podophyllotoxin biosynthesis.ResultsDeep sequencing of transcriptome with an average coverage of 88.34X yielded 60,089 assembled transcript sequences representing 20,387 unique genes having homology to known genes. Fragments per kilobase of exon per million fragments mapped (FPKM) based expression analysis revealed genes related to growth and development were over-expressed at 15°C, whereas genes involved in stress response were over-expressed at 25°C. There was a decreasing trend of podophyllotoxin accumulation at 25°C; data was well supported by the expression of corresponding genes of the pathway. FPKM data was validated by quantitative real-time polymerase chain reaction data using a total of thirty four genes and a positive correlation between the two platforms of gene expression was obtained. Also, detailed analyses yielded cytochrome P450s, methyltransferases and glycosyltransferases which could be the potential candidate hitherto unidentified genes of podophyllotoxin biosynthesis pathway.ConclusionsThe present work revealed temperature responsive transcriptome of S. hexandrum on Illumina platform. Data suggested expression of genes for growth and development and podophyllotoxin biosynthesis at 15°C, and prevalence of those associated with stress response at 25°C.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2164-15-871) contains supplementary material, which is available to authorized users.

Methyl jasmonate treatment increases podophyllotoxin production in Podophyllum hexandrum roots under glasshouse conditions

“…However, the podophyllotoxin production normalized to the root biomass was neither effected by various soils nor temperatures. This is in contrast to the report of Kumari and coworkers who observed a decreasing trend of podophyllotoxin accumulation at 25°C in growth chambers under controlled artificial light (Kumari et al 2014). This contrast in findings can be explained by the importance of sunlight duration on the production of podophyllotoxin (Cushman et al 2005;Liu et al 2015).…”

“…However, the benefit of the quick methanol extraction method is a shorter and easier extraction procedure and usage of less organic solvent. Environmental conditions like soil composition and temperature are important parameters for P. hexandrum cultivation and podophyllotoxin production Kumari et al 2014). Therefore, root biomass and podophyllotoxin production were determined for two soil types (sand and peat-perlite) and two temperatures (15°C and 25°C).…”

“…Alam and Naik found that high podophyllotoxin production was correlated to low pH, high organic content and high nitrogen levels in the soil (Alam and Naik 2009). Another factor important for the production of podophyllotoxin is temperature as some lignan biosynthesis genes were found to exhibit a higher expression level at 15°C rather than at 25°C (Kumari et al 2014). Until now, the influence of soil composition and cultivation temperature on podophyllotoxin production in P. hexandrum roots has not been investigated in a glasshouse.…”

High-throughput sequencing in medicinal plant transcriptome studies

“…Among these unigenes, 27 (83 ESTs) encoded UDP-glycosyltransferases (UGTs), which are involved in the biosynthesis of secondary metabolites. UGTs are involved in the biosynthesis of lignin (Kumari et al, 2014). From these two categories, 17 contigs were chosen for organ-specific expression pattern analysis by real-time PCR.…”

Therapeutic values, chemical constituents and toxicity of Taiwanese Dysosma pleiantha – A review

“…3. Proposed biosynthetic pathway of Podophyllotoxin: Solid arrow indicates know steps whereas broken arrow indicates putative reaction; *shows uncharacterized step.Enzyme abbreviations are as follows: PAL, phenylalanine ammonia lyase; C4H, cinnamate 4-hydroxylase; 4CL, 4-coumarate; CoA, ligase; HCT, p-hydroxycinnamoyl-CoA; quinate shikimate p-hydroxycinnamoyl transferase; C3H, p-coumarate 3-hydroxylase; CCoAOMT, caffeoyl-CoA O-methyltransferase; COMT: caffeic acid 3-O-methyltransferase; CCR, cinnamoyl-CoA reductase; CAD, cinnamyl alcohol dehydrogenase; DPO, dirigent protein oxidase; PLR, pinoresinol-lariciresinol reductase; SLD, secoisolariciresinol dehydrogenase; DOP7H, deoxypodophyllotoxin 7-hydroxylase(Kumari et al, 2014).…”