title: Deoxyxylulose 5-phosphate reductoisomerase is not a rate-determining enzyme for essential oil production in spike lavender.
abstract: Spike lavender (Lavandula latifolia) is an economically important aromatic plant producing essential oils, whose components (mostly monoterpenes) are mainly synthesized through the plastidial methylerythritol 4-phosphate (MEP) pathway. 1-Deoxy-D-xylulose-5-phosphate (DXP) synthase (DXS), that catalyzes the first step of the MEP pathway, plays a crucial role in monoterpene precursors biosynthesis in spike lavender. To date, however, it is not known whether the DXP reductoisomerase (DXR), that catalyzes the conversion of DXP into MEP, is also a rate-limiting enzyme for the biosynthesis of monoterpenes in spike lavender. To investigate it, we generated transgenic spike lavender plants constitutively expressing the Arabidopsis thaliana DXR gene. Although two out of the seven transgenic T0 plants analyzed accumulated more essential oils than the controls, this is hardly imputable to the DXR transgene effect since a clear correlation between transcript accumulation and monoterpene production could not be established. Furthermore, these increased essential oil phenotypes were not maintained in their respective T1 progenies. Similar results were obtained when total chlorophyll and carotenoid content in both T0 transgenic plants and their progenies were analyzed. Our results then demonstrate that DXR enzyme does not play a crucial role in the synthesis of plastidial monoterpene precursors, suggesting that the control flux of the MEP pathway in spike lavender is primarily exerted by the DXS enzyme.
authors.affiliation: Departamento de Biología Vegetal, Universidad de Valencia, Av. Vicent Andrés Estellés s/n, 46100 Burjasot, Valencia, Spain; ISIC/ERI de Biotecnología y Biomedicina, Universidad de Valencia, Av. Vicent Andrés Estellés s/n, 46100 Burjasot, Valencia, Spain.
authors.forename: Isabel
authors.initials: I
authors.lastname: Mendoza-Poudereux
authors.affiliation: Departamento de Biología Vegetal, Universidad de Valencia, Av. Vicent Andrés Estellés s/n, 46100 Burjasot, Valencia, Spain.
authors.forename: Jesús
authors.initials: J
authors.lastname: Muñoz-Bertomeu
authors.affiliation: Departamento de Biología Vegetal, Universidad de Valencia, Av. Vicent Andrés Estellés s/n, 46100 Burjasot, Valencia, Spain; ISIC/ERI de Biotecnología y Biomedicina, Universidad de Valencia, Av. Vicent Andrés Estellés s/n, 46100 Burjasot, Valencia, Spain.
authors.forename: Isabel
authors.initials: I
authors.lastname: Arrillaga
authors.affiliation: Departamento de Biología Vegetal, Universidad de Valencia, Av. Vicent Andrés Estellés s/n, 46100 Burjasot, Valencia, Spain; ISIC/ERI de Biotecnología y Biomedicina, Universidad de Valencia, Av. Vicent Andrés Estellés s/n, 46100 Burjasot, Valencia, Spain. Electronic address: juan.segura@uv.es.
authors.forename: Juan
authors.initials: J
authors.lastname: Segura
mesh_terms: D019747:Aldose-Ketose Isomerases / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D002338:Carotenoids / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D004896:Erythritol / Q000031:analogs & derivatives / Q000378:metabolism; D035264:Flowers / Q000737:chemistry / Q000201:enzymology / Q000235:genetics; D015870:Gene Expression; D027523:Lavandula / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics; D039821:Monoterpenes / Q000378:metabolism; D009822:Oils, Volatile / Q000378:metabolism*; D010641:Phenotype; D018515:Plant Leaves / Q000737:chemistry / Q000201:enzymology / Q000235:genetics; D010938:Plant Oils / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D013403:Sugar Phosphates / Q000378:metabolism; D014166:Transferases / Q000235:genetics / Q000378:metabolism*
chemical_list: C114232:2-C-methylerythritol 4-phosphate; D029681:Arabidopsis Proteins; D039821:Monoterpenes; D009822:Oils, Volatile; D010938:Plant Oils; D010940:Plant Proteins; D013403:Sugar Phosphates; D002734:Chlorophyll; D002338:Carotenoids; C114231:1-deoxy-D-xylulose 5-phosphate reductoisomerase; D014166:Transferases; C109461:deoxyxylulose-5-phosphate synthase; D019747:Aldose-Ketose Isomerases; D004896:Erythritol
keywords: DXR enzyme; DXS enzyme; Essential oil; Monoterpene; Spike lavender