title: Influence of human lactoferrin expression on iron homeostasis, flavonoids, and antioxidants in transgenic tobacco.
abstract: This study was aimed at to check the influence of human lactoferrin (hLF) expression on iron homeostasis, flavonoids, and antioxidants in transgenic tobacco. Transgenic tobacco expressing hLF cDNA under the control of a CaMV 35S promoter was produced. The iron content as well as chlorophyll content of transgenic tobacco was lower compared to mock and untransformed wild plants. Interestingly, hLF transgenic tobacco showed higher level of transcript expression for genes related to iron content regulation like iron transporter and metal transporter. While expression of genes related to iron storage such as ferritin 1 and ferritin 2 was downregulated. The transcript expression of genes encoding antioxidant enzymes such as glutathione reductase, glutathione-S-transferase, ascorbate peroxidase, and catalase was downregulated in hLF transgenic tobacco compared to controls. Further, the transcript expression of two important genes encoding dihydroflavonol reductase (DFR) and phenylalanine ammonia lyase regulatory enzymes of flavonoid biosynthesis pathway was analyzed. The expression of DFR was found to be downregulated, while PAL expression was upregulated in hLF transgenic tobacco compared to mock and untransformed wild plant. Total phenolics, flavonoids, and proanthocyanidins contents were found to be higher in hLF transgenic tobacco than the mock and untransformed wild plant. Results suggest that hLF expression in transgenic tobacco leads to iron deficiency, downregulation of antioxidant enzymes, and increase in total flavonoids.
authors.affiliation: Plant Metabolic Engineering, Biotechnology Division, CSIR-Institute of Himalayan Bioresource Technology, Council of Scientific and Industrial Research, Palampur 176061, Himachal Pradesh, India.
authors.forename: Vinay
authors.initials: V
authors.lastname: Kumar
authors.forename: Tejpal
authors.initials: T
authors.lastname: Gill
authors.forename: Sunita
authors.initials: S
authors.lastname: Grover
authors.forename: Paramvir Singh
authors.initials: PS
authors.lastname: Ahuja
authors.forename: Sudesh Kumar
authors.initials: SK
authors.lastname: Yadav
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D001709:Biotechnology; D002734:Chlorophyll / Q000378:metabolism; D003001:Cloning, Molecular; D005419:Flavonoids / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D006706:Homeostasis; D006801:Humans; D007501:Iron / Q000378:metabolism*; D007781:Lactoferrin / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D053858:Metabolic Networks and Pathways; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D005419:Flavonoids; C490098:LTF protein, human; D011994:Recombinant Proteins; D002734:Chlorophyll; D007501:Iron; D007781:Lactoferrin