title: Nitrogen redistribution and its relationship with the expression of GmATG8c during seed filling in soybean.
abstract: It is well known that some nitrogen in the vegetative organs is redistributed to the seeds during seed filling in soybean (Glycine max [L.] Merrill). This redistribution is considered to affect the seed yield of soybean. However, it is still not clear when the nitrogen moves from the vegetative part to the seeds, and the relationship between nitrogen redistribution and leaf senescence has not been clarified. The soybean variety Fukuyutaka was grown in the experimental field of Saga University, Japan from 22 July to 31 October, 2014. After the first flower stage (R1), the plant samples were collected weekly and were separated into leaf, petiole, stem, podshell and seed. The nitrogen concentrations in each plant part were determined. Fresh leaf samples were provided for the determination of soluble protein and autophagy gene GmATG8c expression. The nitrogen that accumulated in the vegetative parts reached its highest level at 60days after sowing (DAS), then began to decrease at 73DAS (R6). This decrease is considered to be the consequence of nitrogen redistribution from the vegetative parts to the seeds. The movement of nitrogen from the vegetative parts to the seeds was estimated to occur at around 73DAS (R6). At this stage, leaf SPAD values, leaf nitrogen, and soluble protein concentrations began to decrease simultaneously, suggesting the onset of leaf senescence. Furthermore, the expression of the autophagy gene GmATG8c in the leaves increased dramatically from 73 to 85DAS, which is the duration of nitrogen redistribution. The results suggest that the nitrogen redistribution from the vegetative parts to the seeds could be one of the initiating factors of leaf senescence, and the autophagy gene GmATG8c was associated with this process.
authors.affiliation: The United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima 890-0065, Japan; Agrotechnology Discipline, Khulna University, Khulna 9208, Bangladesh.
authors.forename: Md Matiul
authors.initials: MM
authors.lastname: Islam
authors.affiliation: Faculty of Agriculture, Kyushu University, Fukuoka 812-8581, Japan.
authors.forename: Yushi
authors.initials: Y
authors.lastname: Ishibashi
authors.affiliation: Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka 812-8581, Japan.
authors.forename: Andressa C S
authors.initials: AC
authors.lastname: Nakagawa
authors.affiliation: Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka 812-8581, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Tomita
authors.affiliation: Faculty of Agriculture, Kyushu University, Fukuoka 812-8581, Japan.
authors.forename: Mari
authors.initials: M
authors.lastname: Iwaya-Inoue
authors.affiliation: Faculty of Agriculture, Saga University, Saga 840-8502, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Arima
authors.affiliation: Faculty of Agriculture, Saga University, Saga 840-8502, Japan. Electronic address: teis@cc.saga-u.ac.jp.
authors.forename: Shao-Hui
authors.initials: SH
authors.lastname: Zheng
mesh_terms: D000071190:Autophagy-Related Protein 8 Family / Q000235:genetics / Q000378:metabolism; D018533:Biomass; D018506:Gene Expression Regulation, Plant; D009584:Nitrogen / Q000378:metabolism*; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018547:Plant Stems / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D012639:Seeds / Q000235:genetics / Q000378:metabolism; D013025:Glycine max / Q000235:genetics* / Q000378:metabolism
chemical_list: D000071190:Autophagy-Related Protein 8 Family; D010940:Plant Proteins; D009584:Nitrogen
keywords: Autophagy; GmATG8c; Nitrogen accumulation; Nitrogen redistribution; Senescence; Soybean