title: An engineered lipid remodeling system using a galactolipid synthase promoter during phosphate starvation enhances oil accumulation in plants.
abstract: Inorganic phosphate (Pi) depletion is a serious problem for plant growth. Membrane lipid remodeling is a defense mechanism that plants use to survive Pi-depleted conditions. During Pi starvation, phospholipids are degraded to supply Pi for other essential biological processes, whereas galactolipid synthesis in plastids is up-regulated via the transcriptional activation of monogalactosyldiacylglycerol synthase 3 (MGD3). Thus, the produced galactolipids are transferred to extraplastidial membranes to substitute for phospholipids. We found that, Pi starvation induced oil accumulation in the vegetative tissues of various seed plants without activating the transcription of enzymes involved in the later steps of triacylglycerol (TAG) biosynthesis. Moreover, the Arabidopsis starchless phosphoglucomutase mutant, pgm-1, accumulated higher TAG levels than did wild-type plants under Pi-depleted conditions. We generated transgenic plants that expressed a key gene involved in TAG synthesis using the Pi deficiency-responsive MGD3 promoter in wild-type and pgm-1 backgrounds. During Pi starvation, the transgenic plants accumulated higher TAG amounts compared with the non-transgenic plants, suggesting that the Pi deficiency-responsive promoter of galactolipid synthase in plastids may be useful for producing transgenic plants that accumulate more oil under Pi-depleted conditions.
authors.affiliation: Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology Yokohama, Japan.
authors.forename: Mie
authors.initials: M
authors.lastname: Shimojima
authors.affiliation: Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology Yokohama, Japan.
authors.forename: Yuka
authors.initials: Y
authors.lastname: Madoka
authors.affiliation: Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology Yokohama, Japan.
authors.forename: Ryota
authors.initials: R
authors.lastname: Fujiwara
authors.affiliation: Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology Yokohama, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Murakawa
authors.affiliation: Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology Yokohama, Japan.
authors.forename: Yushi
authors.initials: Y
authors.lastname: Yoshitake
authors.affiliation: Technical Department, Biomaterial Analysis Center, Tokyo Institute of Technology Yokohama, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Ikeda
authors.affiliation: Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology Yokohama, Japan.
authors.forename: Ryota
authors.initials: R
authors.lastname: Koizumi
authors.affiliation: Biological Science Laboratories, Kao Corporation Tochigi, Japan.
authors.forename: Keiji
authors.initials: K
authors.lastname: Endo
authors.affiliation: Biological Science Laboratories, Kao Corporation Tochigi, Japan.
authors.forename: Katsuya
authors.initials: K
authors.lastname: Ozaki
authors.affiliation: Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology Yokohama, Japan ; Core Research for Evolutional Science and Technology, Japan Science and Technology Agency Tokyo, Japan ; Earth-Life Science Institute, Tokyo Institute of Technology Tokyo, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ohta
keywords: galactolipid; monogalactosyldiacylglycerol; phosphate starvation; promoter; starch; triacylglycerol