title: A phenylalanine ammonia-lyase ortholog (PkPAL1) from Picrorhiza kurrooa Royle ex. Benth: molecular cloning, promoter analysis and response to biotic and abiotic elicitors.
abstract: Picrorhiza kurrooa Royle ex Benth. is a highly reputed medicinal herb utilised in the preparation of a number of herbal drug formulations, principally due to the presence of novel monoterpene iridoid glycosides kenned as picrosides. Phenylalanine ammonia-lyase catalyses an important rate-limiting step in phenylpropanoid pathway and supplies precursors like cinnamic acid, vanillic acid, ferulic acid, etc., to a variety of secondary metabolites including picrosides. The imperilled status of P. kurrooa coupled with lack of information regarding biogenesis of picrosides necessitates deciphering the biosynthetic pathway for picrosides. In the present study, a PAL gene, designated PkPAL1 was isolated from P. kurrooa. The cDNA is 2312 bp in length, consisting of an ORF of 2142 bp encoding for a 713 amino acid protein having a predicted molecular weight of 77.66 kDa and an isoelectric point of pH 6.82. qRT-PCR analysis of various tissues of P. kurrooa showed that PkPAL1 transcript levels were highest in the leaves, consistent with picroside accumulation pattern. Using Genome walking, a 718 bp promoter region was also isolated resulting in identification of distinct cis-regulatory elements including TGA-element, TGACG-motif, CGTCA-motif, etc. qRT-PCR indicated up-regulation of PkPAL1 by methyl jasmonate, salicylic acid, 2,4-dicholorophenoxy acetic acid and UV-B elicitations that corroborated positively with the identified cis-elements within the promoter region. Moreover, altitude was found to have a positive effect on the PkPAL1 transcript levels, driving the expression of PkPAL1 abundantly. Based on docking analysis, we identified eight residues as potentially essential for substrate binding in PkPAL1.
authors: Plant Biotechnology Division, CSIR - Indian Institute of Integrative Medicine, Canal Road, Jammu Tawi-180001, India.
authors: Wajid Waheed
authors: WW
authors: Bhat
authors: Plant Biotechnology Division, CSIR - Indian Institute of Integrative Medicine, Canal Road, Jammu Tawi-180001, India.
authors: Sumeer
authors: S
authors: Razdan
authors: Plant Biotechnology Division, CSIR - Indian Institute of Integrative Medicine, Canal Road, Jammu Tawi-180001, India.
authors: Satiander
authors: S
authors: Rana
authors: Plant Biotechnology Division, CSIR - Indian Institute of Integrative Medicine, Canal Road, Jammu Tawi-180001, India.
authors: Niha
authors: N
authors: Dhar
authors: Genetic Resources and Agrotechnology Division, CSIR - Indian Institute of Integrative Medicine, Canal Road, Jammu Tawi, 180001, India.
authors: Tariq Ahmad
authors: TA
authors: Wani
authors: Microbial Biotechnology Division, CSIR - Indian Institute of Integrative Medicine, Sanat Nagar, Srinagar 190005, India.
authors: Parvaiz
authors: P
authors: Qazi
authors: Medicinal Chemistry Division, CSIR - Indian Institute of Integrative Medicine, Canal Road, Jammu Tawi, 180001, India.
authors: Ram
authors: R
authors: Vishwakarma
authors: Plant Biotechnology Division, CSIR - Indian Institute of Integrative Medicine, Canal Road, Jammu Tawi-180001, India. Electronic address: sklattoo@iiim.ac.in.
authors: Surrinder K
authors: SK
authors: Lattoo
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites; D003001:Cloning, Molecular; D062105:Molecular Docking Simulation; D008969:Molecular Sequence Data; D010649:Phenylalanine / Q000378:metabolism; D010650:Phenylalanine Ammonia-Lyase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D032261:Picrorhiza / Q000201:enzymology* / Q000235:genetics / Q000528:radiation effects; D018515:Plant Leaves / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013472:Sunlight
chemical_list: D010940:Plant Proteins; D012333:RNA, Messenger; D010649:Phenylalanine; D010650:Phenylalanine Ammonia-Lyase
keywords: Elicitors; Iridoids; Molecular docking; Phenylalanine ammonia-lyase; Picrorhiza kurrooa; Picrosides