title: Pod removal responsive change in phytohormones and its impact on protein degradation and amino acid transport in source leaves of Brassica napus.
abstract: To characterize the hormonal regulation of nitrogen remobilization from source to pod filling in Brassica napus, the hormonal level, proteolytic process, and amino acid transport were assessed in mature leaves of pod-removed or control at the early pod-filling stage. Pod (sink) removal decreased salicylic acid (SA), and significantly increased jasmonic acid (JA). The SA/JA ratio decreased with pod removal, accompanied by low degradation of foliar proteins and Rubisco content. A significant decrease in protease activity was observed in pod-removed leaves, confirmed by in-gel staining of protease. Pod removal reduced the expression of four amino acid transporter genes (BnAAP1, BnAAP2, BnAAP4, and BnAAP6) in mature leaves and reduced amino acid loading into phloem. These results indicated that a decrease in SA resulting from pod removal down-regulated nitrogen remobilization accompanied by a decrease in proteolytic activity and amino acid transport in mature leaves at the pod-filling stage.
authors.affiliation: Department of Animal Science, Institute of Agricultural Science and Technology, College of Agriculture & Life Science, Chonnam National University, Gwangju 500-600, Republic of Korea; Biotechnology Research Institute, Chonnam National University, Gwangju 500-757, Republic of Korea.
authors.forename: Bok-Rye
authors.initials: BR
authors.lastname: Lee
authors.affiliation: Department of Animal Science, Institute of Agricultural Science and Technology, College of Agriculture & Life Science, Chonnam National University, Gwangju 500-600, Republic of Korea.
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Central Instrument Facility, Gyeongsang National University, Jinju 600-701, Republic of Korea.
authors.forename: Dong-Won
authors.initials: DW
authors.lastname: Bae
authors.affiliation: Department of Animal Science, Institute of Agricultural Science and Technology, College of Agriculture & Life Science, Chonnam National University, Gwangju 500-600, Republic of Korea. Electronic address: grassl@chonnam.ac.kr.
authors.forename: Tae-Hwan
authors.initials: TH
authors.lastname: Kim
mesh_terms: D026905:Amino Acid Transport Systems / Q000378:metabolism; D000596:Amino Acids / Q000378:metabolism*; D001692:Biological Transport; D029688:Brassica napus / Q000378:metabolism*; D003517:Cyclopentanes / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D054883:Oxylipins / Q000378:metabolism; D010447:Peptide Hydrolases / Q000378:metabolism; D010937:Plant Growth Regulators / Q000378:metabolism*; D018515:Plant Leaves / Q000378:metabolism*; D010940:Plant Proteins / Q000378:metabolism; D059748:Proteolysis; D020156:Salicylic Acid / Q000378:metabolism
chemical_list: D026905:Amino Acid Transport Systems; D000596:Amino Acids; D003517:Cyclopentanes; D054883:Oxylipins; D010937:Plant Growth Regulators; D010940:Plant Proteins; C011006:jasmonic acid; D010447:Peptide Hydrolases; D020156:Salicylic Acid
keywords: Amino acid transport; Brassica napus; Pod removal; Proteolysis; Salicylic acid