title: Deep rooting conferred by DEEPER ROOTING 1 enhances rice yield in paddy fields.
abstract: To clarify the effect of deep rooting on grain yield in rice (Oryza sativa L.) in an irrigated paddy field with or without fertilizer, we used the shallow-rooting IR64 and the deep-rooting Dro1-NIL (a near-isogenic line homozygous for the Kinandang Patong allele of DEEPER ROOTING 1 (DRO1) in the IR64 genetic background). Although total root length was similar in both lines, more roots were distributed within the lower soil layer of the paddy field in Dro1-NIL than in IR64, irrespective of fertilizer treatment. At maturity, Dro1-NIL showed approximately 10% higher grain yield than IR64, irrespective of fertilizer treatment. Higher grain yield of Dro1-NIL was mainly due to the increased 1000-kernel weight and increased percentage of ripened grains, which resulted in a higher harvest index. After heading, the uptake of nitrogen from soil and leaf nitrogen concentration were higher in Dro1-NIL than in IR64. At the mid-grain-filling stage, Dro1-NIL maintained higher cytokinin fluxes from roots to shoots than IR64. These results suggest that deep rooting by DRO1 enhances nitrogen uptake and cytokinin fluxes at late stages, resulting in better grain filling in Dro1-NIL in a paddy field in this study.
authors.affiliation: NARO Institute of Crop Science (NICS), 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518, Japan.
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Arai-Sanoh
authors.affiliation: NARO Institute of Crop Science (NICS), 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Takai
authors.affiliation: 1] NARO Institute of Crop Science (NICS), 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518, Japan [2] NARO Agricultural Research Center (NARO/ARC), 1-2-1 Inada, Joetsu, Niigata 943-0193, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yoshinaga
authors.affiliation: NARO Institute of Crop Science (NICS), 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakano
authors.affiliation: RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro, Tsurumi, Yokohama 230-0045, Japan.
authors.forename: Mikiko
authors.initials: M
authors.lastname: Kojima
authors.affiliation: RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro, Tsurumi, Yokohama 230-0045, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Sakakibara
authors.affiliation: NARO Institute of Crop Science (NICS), 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518, Japan.
authors.forename: Motohiko
authors.initials: M
authors.lastname: Kondo
authors.affiliation: National Institute of Agrobiological Sciences (NIAS), 2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602, Japan.
authors.forename: Yusaku
authors.initials: Y
authors.lastname: Uga
mesh_terms: D005308:Fertilizers; D017343:Genes, Plant; D006824:Hybridization, Genetic; D009584:Nitrogen / Q000378:metabolism; D012275:Oryza / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D053147:Plant Exudates / Q000378:metabolism; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D012639:Seeds / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism
chemical_list: D005308:Fertilizers; D053147:Plant Exudates; D009584:Nitrogen