title: Effect of nitrate on nodule and root growth of soybean (Glycine max (L.) Merr.).
abstract: The application of combined nitrogen, especially nitrate, to soybean plants is known to strongly inhibit nodule formation, growth and nitrogen fixation. In the present study, we measured the effects of supplying 5 mM nitrate on the growth of nodules, primary root, and lateral roots under light at 28 °C or dark at 18 °C conditions. Photographs of the nodulated roots were periodically taken by a digital camera at 1-h intervals, and the size of the nodules was measured with newly developed computer software. Nodule growth was depressed approximately 7 h after the addition of nitrate under light conditions. The nodule growth rate under dark conditions was almost half that under light conditions, and nodule growth was further suppressed by the addition of 5 mM nitrate. Similar results were observed for the extending growth rate of the primary root as those for nodule growth supplied with 5 mM nitrate under light/dark conditions. In contrast, the growth of lateral roots was promoted by the addition of 5 mM nitrate. The 2D-PAGE profiles of nodule protein showed similar patterns between the 0 and 5 mM nitrate treatments, which suggested that metabolic integrity may be maintained with the 5 mM nitrate treatment. Further studies are required to confirm whether light or temperature condition may give the primary effect on the growth of nodules and roots.
authors.affiliation: Graduate School of Science and Technology, Niigata University, Niigata 950-2181, Japan. akinori1221@gmail.com.
authors.forename: Akinori
authors.initials: A
authors.lastname: Saito
authors.affiliation: Graduate School of Science and Technology, Niigata University, Niigata 950-2181, Japan. sayuri.tanabata@gmail.com.
authors.forename: Sayuri
authors.initials: S
authors.lastname: Tanabata
authors.affiliation: RIKEN Center for Sustainable Resource Science, Ibaraki 305-0074, Japan. takanari.tanabata@riken.jp.
authors.forename: Takanari
authors.initials: T
authors.lastname: Tanabata
authors.affiliation: Graduate School of Science and Technology, Niigata University, Niigata 950-2181, Japan. sayuri.tanabata@gmail.com.
authors.forename: Seiya
authors.initials: S
authors.lastname: Tajima
authors.affiliation: Graduate School of Science and Technology, Niigata University, Niigata 950-2181, Japan. manabu-u@adeka.co.jp.
authors.forename: Manabu
authors.initials: M
authors.lastname: Ueno
authors.affiliation: Graduate School of Science and Technology, Niigata University, Niigata 950-2181, Japan. ishikawa@agr.niigata-u.ac.jp.
authors.forename: Shinji
authors.initials: S
authors.lastname: Ishikawa
authors.affiliation: Graduate School of Science and Technology, Niigata University, Niigata 950-2181, Japan. ohtake@agr.niigata-u.ac.jp.
authors.forename: Norikuni
authors.initials: N
authors.lastname: Ohtake
authors.affiliation: Graduate School of Science and Technology, Niigata University, Niigata 950-2181, Japan. sueyoshi@agr.niigata-u.ac.jp.
authors.forename: Kuni
authors.initials: K
authors.lastname: Sueyoshi
authors.affiliation: Graduate School of Science and Technology, Niigata University, Niigata 950-2181, Japan. ohyama@agr.niigata-u.ac.jp.
authors.forename: Takuji
authors.initials: T
authors.lastname: Ohyama
mesh_terms: D003624:Darkness; D004305:Dose-Response Relationship, Drug; D015180:Electrophoresis, Gel, Two-Dimensional; D008027:Light; D009566:Nitrates / Q000494:pharmacology*; D010940:Plant Proteins / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D053204:Root Nodules, Plant / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D013025:Glycine max / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D013559:Symbiosis / Q000187:drug effects; D013696:Temperature; D059008:Time-Lapse Imaging; D014741:Video Recording
chemical_list: D009566:Nitrates; D010940:Plant Proteins