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Plant Cell Rep (2010) 29:747755 DOI 10.1007/s00299-010-0861-5
ORIGINAL PAPER
Characterization of isoavone synthase gene from Psoralea corylifolia: a medicinal plant
Prashant Misra Ashutosh Pandey
Shri Krishna Tewari Pravendra Nath
Prabodh Kumar Trivedi
Received: 25 February 2010 / Revised: 29 March 2010 / Accepted: 15 April 2010 / Published online: 1 May 2010 Springer-Verlag 2010
Abstract Isoavones are known to possess medicinal properties and implicated in plantpathogen interaction. We have for the rst time isolated and functionally characterized an isoavones synthase (IFS) gene from a traditionally acclaimed medicinal plant Psoralea corylifolia abundantly growing in tropical and subtropical regions. The IFS catalyzes the exclusive reaction of phenylpropanoid pathway in leguminous plants to produce isoavones. The full-length cDNA (PcIFS) of the gene comprised 1,563 bp and putatively encodes a polypeptide of 520 amino acid residues. The gene is expressed ubiquitously although at varying levels in different parts of the plant. The expression analysis suggests that the gene is responsive to methyl jasmonate, salicylic acid and wounding. Overexpression of PcIFS in non-leguminous tobacco plant led to the accumulation of isoavones in petal tissue, suggesting it a functional gene from P. corylifolia involved in isoavones biosynthesis.
Keywords Isoavone Metabolic engineering
PcIFS Transgenic plant
Introduction
Array of plant avonoids, such as aurones, avons, avonols, anthocyanins, condensed tannins, avonones and isoavones are synthesized through phenylpropanoid pathway (Fig. 1). These compounds have been shown to offer protection against hormone-dependant cancers, cardiovascular diseases, osteoporosis and menopausal symptoms (Cornwell et al. 2004; Dixon 2004). Out of avonoids, isoavonoids are almost exclusively produced in leguminous plants. These have also been implicated in plantmicrobe/fungal interaction and its synthesis is known to be induced by defense signal elicitors, such as jasmonic acid and salicylic acid (Van Rhijn and Vanderleyden 1995; Pueppke 1996; Dixon 1999). The biosynthesis of isoavonoids is catalyzed by a legume-specic cytochrome P450 enzyme, 2-hydroxyisoavanone synthase commonly referred as IFS. The IFS catalyzed reaction results into the formation of 2-hydroxyisoava-none intermediate which is unstable and dehydrates to yield the corresponding isoavone either spontaneously or with the aid of an enzyme hydroxyisoavanone dehydratase (Hashim et al. 1990; Dixon 1999; Akashi et al. 2005). The gene for IFS has been cloned from plants, such as soybean, alfalfa and red clover and shown to belong to multigene family (Steele...