The role of calcium in regulating alginate-derived oligosaccharides in nitrogen metabolism of Brassica campestris L. var. utilis Tsen et Lee

Abstract

The role of calcium in regulating alginate-derived oligosaccharides in nitrogen metabolism of Brassica campestris L. var. utilis Tsen et Lee Abstract Under normal (full-strength) levels of calcium in hydroponics culture, alginate-derived oligosaccharides (ADOs) increased the activity of nitrate reductase (NR), glutamine synthetase (GS), glutamate dehydrogenase (GDH), and endpeptidase (EP) in leaves by 4.04-14. 41%, 23.57-190.12%, 103.44-265.21%, and 7.22-157.41% respectively compared to that in leaves of the control plants; increased the concentration of NH 4 ? -N, total nitrogen, and protein nitrogen in leaves; and decreased the concentration of nitrate in shoots. Under low (5% of the full strength) levels of calcium, ADOs had no effect on the activity of NR and GS. These results serve to confirm the role of ADOs in regulating nitrogen metabolism, which is related to the supply of calcium. ADOs induce the release of calcium from cell organelles and the cell wall into the cytoplasm to activate the enzymes involved in nitrogen metabolism. Thus Ca regulates nitrogen metabolism in Chinese cabbage through ADOs. Keywords Alginate-derived oligosaccharide Á Flowering Chinese cabbage (Brassica campestris L. var. utilis Tsen et Lee) Á Nitrogen metabolism Á Calcium Abbreviations ADOs Alginate-derived oligosaccharides ATP Adenosine triphosphate EDTA-2Na Ethylene diamine tetraacetic acid disodium salt EP Endopeptidase GDH Glutamate dehydrogenase GOGAT Glutamate synthetase GS Glutamine synthetase NADH Nicotinamide-adenine dinucleotid NADPH Nicotinamide adenine dinucleotide phosphate NH 4 ? -N Ammonia nitrogen NO 3 --N Nitrate nitrogen NR Nitrate reductase

Calcium Alleviates Temperature Stress by Regulating Nitrogen and Respiratory Metabolism in Malus baccata Roots

“…According to recent studies, NR and GS activities were activated by Ca 2+ (Zhang et al, 2011). In this experiment, the CaCl2 treatment significantly increased the activities of NR, GS, GOGAT and GDH under temperature stress compared to the control (Fig.…”

Comparative Proteomic Analysis Reveals the Effects of Exogenous Calcium against Acid Rain Stress in Liquidambar formosana Hance Leaves

“…AR stress severely affects the material metabolism of plants, including disturbing nitrogen (N) metabolism and changing free amino acid levels in plants. , There is growing evidence that Ca enhances plant resistance to environmental stresses by regulating material metabolism. ,,, In this study, exogenous Ca impacted the abundances of a series of proteins involving in several metabolism processes including nitrogen metabolism (spots 7, 58, 81), secondary metabolite metabolism (spots 6, 13, 14, 78), carbohydrate metabolism (spots 17, 28, 68, 69, 80), starch biosynthesis (spot 53), and amino-acid biosynthesis (spots 56, 65). Glutamine synthetase (GS) is a key enzyme in plant N assimilation, as it catalyzes the first step in the conversion of inorganic N (ammonium) into its organic form glutamine, which can be activated by Ca . Under AR stress, our data revealed that exogenous Ca supply reversed the decrease in expression of GS (spots 7, 58, 81) caused by low Ca condition.…”

Alginate oligosaccharides enhanced Triticum aestivum L. tolerance to drought stress

“…Further researches demonstrated that AOS can alleviate plant damages caused by abiotic stress such as high salt [18] and heavy metal [19]. In our laboratory, AOS from alginate degraded by Streptomyces violaceoruber, have been applied as effective growth promoter for plant [20]. However, there are scarce studies about the effects of AOS on drought stress resistance.…”