Innate endophytic fungus, Aspergillus terreus as biotic elicitor of withanolide A in root cell suspension cultures of Withania somnifera

• Published in: Molecular biology reports Vol. 46; no. 2; pp. 1895 - 1908
• Main Authors: Kushwaha, Ramesh Kumar, Singh, Sucheta, Pandey, Shiv Shanker, Kalra, Alok, Vivek Babu, Chikkarasanahalli Shivegowda
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-04-2019; Springer Nature B.V
• Subjects: Animal Anatomy; Animal Biochemistry; Aspergillus - metabolism; Aspergillus - physiology; Aspergillus terreus; Biomedical and Life Sciences; Biosynthetic Pathways; Cell culture; Cell Culture Techniques; Chromatography, High Pressure Liquid - methods; Endophytes; Fungi; Histology; Hydrogen peroxide; Hydrogen Peroxide - chemistry; Life Sciences; Lipid peroxidation; Morphology; Mycelia; Original Article; Plant Roots - metabolism; Salicylic acid; Salicylic Acid - metabolism; Withania - genetics; Withania - metabolism; Withania somnifera; Withanolides - isolation & purification; Withanolides - metabolism; Endophyte; Suspension culture; Withanolide A; Elicitor; Withania somnifera
• ISSN: 0301-4851; 1573-4978
• DOI: 10.1007/s11033-019-04641-w

In the present study, root cell suspension cultures of
W. somnifera
were elicited with mycelial extract (1% w/v) and culture filtrate (5% v/v) of their native endophytic fungus
Aspergillus terreus
2aWF in shake flask. Culture filtrate of
A. terreus
2aWF significantly elicits withanolide A at 6H (12.20 ± 0.52 µg/g FCB). However, with
A. terreus
2aWF mycelial extract, withanolide A content was higher at 24H (10.29 µg/g FCB). Withanolide A content was maximum with salicylic acid (0.1 mM) treatment at 24H (8.3 ± 0.20 µg/g FCB). Further, expression analysis of withanolide pathway genes, hydrogen peroxide production, and lipid peroxidation was carried out after 48H of elicitation with 2aWF mycelial extract and culture filtrate. The expression levels of withanolides biosynthetic pathway genes, viz.
HMGR, DXR, FPPS, SQS, SQE, CAS, SMT1, STE1
and
CYP710A1
were quantified by real time PCR at 48H of elicitation. In all the treatments, the expression levels of key genes were significantly upregulated as compared to untreated suspension cells. Hydrogen peroxide was noticeably enhanced in SA, mycelia extract and culture filtrate, at 20% (115 ± 4.40 nM/g FCB), 42% (137.5 ± 3.62 nM/g FCB), and 27% (122.8 ± 1.25 nM/g FCB) respectively; however, lipid peroxidation was 0.288 ± 0.014, 0.305 ± 0.041 and 0.253 ± 0.007 (µM/gm FCB) respectively, higher than the control (0.201 ± 0.007 µM/gm FCB).