title: Effects of boron nutrition and water stress on nitrogen fixation, seed δ15N and δ13C dynamics, and seed composition in soybean cultivars differing in maturities.
abstract: Therefore, the objective of the current research was to investigate the effects of foliar B nutrition on seed protein, oil, fatty acids, and sugars under water stress conditions. A repeated greenhouse experiment was conducted using different maturity group (MG) cultivars. Plants were well-watered with no foliar B (W - B), well-watered with foliar B (W + B), water-stressed with no foliar B (WS - B), and water-stressed with foliar B (WS + B). Foliar B was applied at rate of 0.45 kg · ha(-1) and was applied twice at flowering and at seed-fill stages. The results showed that seed protein, sucrose, fructose, and glucose were higher in W + B treatment than in W - B, WS + B, and WS - B. The increase in protein in W + B resulted in lower seed oil, and the increase of oleic in WS - B or WS + B resulted in lower linolenic acid. Foliar B resulted in higher nitrogen fixation and water stress resulted in seed δ (15)N and δ (13)C alteration. Increased stachyose indicated possible physiological and metabolic changes in carbon and nitrogen pathways and their sources under water stress. This research is beneficial to growers for fertilizer management and seed quality and to breeders to use (15)N/(14)N and (13)C/(12)C ratios and stachyose to select for drought tolerance soybean.
authors: Crop Genetics Research Unit, USDA-ARS, Stoneville, MS 38776, USA.
authors: Nacer
authors: N
authors: Bellaloui
authors: Crop Genetics Research Unit, USDA-ARS, Jackson, TN 38301, USA.
authors: Alemu
authors: A
authors: Mengistu
mesh_terms: D001895:Boron / Q000032:analysis / Q000502:physiology*; D002247:Carbon Isotopes / Q000032:analysis; D003681:Dehydration / Q000378:metabolism / Q000503:physiopathology; D005632:Fructose / Q000032:analysis; D005947:Glucose / Q000032:analysis; D009586:Nitrogen Fixation / Q000502:physiology*; D009587:Nitrogen Isotopes / Q000032:analysis; D018515:Plant Leaves / Q000737:chemistry; D010940:Plant Proteins / Q000032:analysis; D012639:Seeds / Q000737:chemistry / Q000502:physiology*; D013025:Glycine max / Q000378:metabolism / Q000502:physiology*; D013395:Sucrose / Q000032:analysis; D017962:alpha-Linolenic Acid / Q000032:analysis
chemical_list: D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D010940:Plant Proteins; D017962:alpha-Linolenic Acid; D005632:Fructose; D013395:Sucrose; D005947:Glucose; D001895:Boron