title: Physiological responses related to increased grain yield under drought in the first biotechnology-derived drought-tolerant maize.
abstract: Maize (Zea mays ssp. mays L.) is highly susceptible to drought stress. This work focused on whole-plant physiological mechanisms by which a biotechnology-derived maize event expressing bacterial cold shock protein B (CspB), MON 87460, increased grain yield under drought. Plants of MON 87460 and a conventional control (hereafter 'control') were tested in the field under well-watered (WW) and water-limited (WL) treatments imposed during mid-vegetative to mid-reproductive stages during 2009-2011. Across years, average grain yield increased by 6% in MON 87460 compared with control under WL conditions. This was associated with higher soil water content at 0.5 m depth during the treatment phase, increased ear growth, decreased leaf area, leaf dry weight and sap flow rate during silking, increased kernel number and harvest index in MON 87460 than the control. No consistent differences were observed under WW conditions. This indicates that MON 87460 acclimated better under WL conditions than the control by lowering leaf growth which decreased water use during silking, thereby eliciting lower stress under WL conditions. These physiological responses in MON 87460 under WL conditions resulted in increased ear growth during silking, which subsequently increased the kernel number, harvest index and grain yield compared to the control.
authors.affiliation: Monsanto Company, St. Louis, MO, 63167, USA.
authors.forename: Krishna S
authors.initials: KS
authors.lastname: Nemali
authors.affiliation: Agrivida, Storrs, CT, 06269, USA.
authors.forename: Christopher
authors.initials: C
authors.lastname: Bonin
authors.affiliation: Monsanto Company, St. Louis, MO, 63167, USA.
authors.forename: Frank G
authors.initials: FG
authors.lastname: Dohleman
authors.affiliation: Monsanto Company, St. Louis, MO, 63167, USA.
authors.forename: Mike
authors.initials: M
authors.lastname: Stephens
authors.affiliation: Monsanto Company, St. Louis, MO, 63167, USA.
authors.forename: William R
authors.initials: WR
authors.lastname: Reeves
authors.affiliation: Monsanto Company, St. Louis, MO, 63167, USA.
authors.forename: Donald E
authors.initials: DE
authors.lastname: Nelson
authors.affiliation: Dow AgroSciences LLC, 12849 Gorman Lane, Woodland, CA, 95695, USA.
authors.forename: Paolo
authors.initials: P
authors.lastname: Castiglioni
authors.affiliation: Monsanto Company, St. Louis, MO, 63167, USA.
authors.forename: Joy E
authors.initials: JE
authors.lastname: Whitsel
authors.affiliation: Monsanto Company, St. Louis, MO, 63167, USA.
authors.forename: Bernard
authors.initials: B
authors.lastname: Sammons
authors.affiliation: Biology Department, Southern Connecticut State University, New Haven, CT, 06515, USA.
authors.forename: Rebecca A
authors.initials: RA
authors.lastname: Silady
authors.affiliation: Monsanto Company, St. Louis, MO, 63167, USA.
authors.forename: Donald
authors.initials: D
authors.lastname: Anstrom
authors.affiliation: Division of Plant Sciences and Interdisciplinary Plant Group, University of Missouri, Columbia, MO, 65211, USA.
authors.forename: Robert E
authors.initials: RE
authors.lastname: Sharp
authors.affiliation: Division of Plant Sciences and Interdisciplinary Plant Group, University of Missouri, Columbia, MO, 65211, USA.
authors.forename: Osric R
authors.initials: OR
authors.lastname: Patharkar
authors.affiliation: Plant Science Department, South Dakota State University, Brookings, SD, 57007, USA.
authors.forename: David
authors.initials: D
authors.lastname: Clay
authors.affiliation: Monsanto Company, St. Louis, MO, 63167, USA.
authors.forename: Marie
authors.initials: M
authors.lastname: Coffin
authors.affiliation: Statistical Consultants Plus, St. Louis, MO, 63167, USA.
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Nemeth
authors.affiliation: Monsanto Company, St. Louis, MO, 63167, USA.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Leibman
authors.affiliation: Monsanto Company, St. Louis, MO, 63167, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Luethy
authors.affiliation: Monsanto Company, St. Louis, MO, 63167, USA.
authors.forename: Mark
authors.initials: M
authors.lastname: Lawson
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D001709:Biotechnology / Q000379:methods*; D055864:Droughts; D002523:Edible Grain; D018515:Plant Leaves / Q000502:physiology; D030821:Plants, Genetically Modified / Q000502:physiology; D012987:Soil / Q000737:chemistry; D003313:Zea mays / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D012987:Soil; C077188:cold-shock protein CspB, Bacteria
keywords: CspB; ear; harvest index; leaf area; sap flow; soil water content; water use; yield