title: Exploiting leaf starch synthesis as a transient sink to elevate photosynthesis, plant productivity and yields.
abstract: Improvements in plant productivity (biomass) and yield have centered on increasing the efficiency of leaf CO(2) fixation and utilization of products by non-photosynthetic sink organs. We had previously demonstrated a correlation between photosynthetic capacity, plant growth, and the extent of leaf starch synthesis utilizing starch-deficient mutants. This finding suggested that leaf starch is used as a transient photosynthetic sink to recycle inorganic phosphate and, in turn, maximize photosynthesis. To test this hypothesis, Arabidopsis thaliana and rice (Oryza sativa L.) lines were generated with enhanced capacity to make leaf starch with minimal impact on carbon partitioning to sucrose. The Arabidopsis engineered plants exhibited enhanced photosynthetic capacity; this translated into increased growth and biomass. These enhanced phenotypes were displayed by similarly engineered rice lines. Manipulation of leaf starch is a viable alternative strategy to increase photosynthesis and, in turn, the growth and yields of crop and bioenergy plants.
authors.affiliation: Institute of Biological Chemistry, Washington State University, Pullman, WA 99164, USA.
authors.forename: Kelly
authors.initials: K
authors.lastname: Gibson
authors.forename: Jong-Sug
authors.initials: JS
authors.lastname: Park
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Nagai
authors.forename: Seon-Kap
authors.initials: SK
authors.lastname: Hwang
authors.forename: Young-Chan
authors.initials: YC
authors.lastname: Cho
authors.forename: Kyung-Hee
authors.initials: KH
authors.lastname: Roh
authors.forename: Si-Myung
authors.initials: SM
authors.lastname: Lee
authors.forename: Dong-Hern
authors.initials: DH
authors.lastname: Kim
authors.forename: Sang-Bong
authors.initials: SB
authors.lastname: Choi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ito
authors.forename: Gerald E
authors.initials: GE
authors.lastname: Edwards
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Okita
mesh_terms: D017360:Arabidopsis / Q000254:growth & development / Q000378:metabolism; D001692:Biological Transport; D018533:Biomass; D050260:Carbohydrate Metabolism; D018556:Crops, Agricultural / Q000235:genetics / Q000378:metabolism; D012275:Oryza / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D010710:Phosphates / Q000378:metabolism; D010788:Photosynthesis; D018515:Plant Leaves / Q000254:growth & development / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D013213:Starch / Q000096:biosynthesis*
chemical_list: D010710:Phosphates; D013213:Starch