Biomaterial Database

Changes in trigonelline (N-methylnicotinic acid) content and nicotinic acid metabolism during germination of mungbean (Phaseolus aureus) seeds. 2005

Xin-Qiang Zheng, and Etsuko Hayashibe, and Hiroshi Ashihara

Department of Advanced Biosciences, Graduate Division of Human Environmental Science, Graduate School of Humanities and Sciences, Ochanomizu University, Bunkyo-ku, Tokyo, 112-8610, Japan.

Changes in trigonelline content and in biosynthetic activity were determined in the cotyledons and embryonic axes of etiolated mungbean (Phaseolus aureus) seedlings during germination. Accumulation of trigonelline (c. 240 nmol per pair of cotyledons) was observed in the cotyledons of dry seeds; trigonelline content decreased 2 d after imbibition. Trigonelline content in the embryonic axes increased with seedling growth and reached a peak (c. 380 nmol per embryonic axis) at day 5. Trigonelline content did not change significantly during the differentiation of hypocotyls, and the concentration was greatest in the apical 5 mm. Nicotinic acid and nicotinamide were better precursors for pyridine nucleotide synthesis than quinolinic acid, but no great differences were found in the synthesis of trigonelline from these three precursors. Trigonelline synthesis was always higher in embryonic axes than in cotyledons. Activity of quinolinate phosphoribosyltransferase (EC 2.4.2.19), nicotinate phosphoribosyltransferase (EC 2.4.2.11), and nicotinamidase (EC 3.5.1.19) was found in cotyledons and embryonic axes, but no nicotinamide phosphoribosyltransferase (EC 2.4.2.12) activity was detected. It follows that quinolinic acid and nicotinic acid were directly converted to nicotinic acid mononucleotide by the respective phosphoribosyltransferases, but nicotinamide appeared to be converted to nicotinic acid mononucleotide after conversion to nicotinic acid. Trigonelline synthase (nicotinate N-methyltransferase, EC 2.1.1.7) activity increased in the embryonic axes, but decreased in cotyledons during germination. [14C]Nicotinic acid and trigonelline absorbed by the cotyledons were transported to the embryonic axes during germination. Trigonelline had no effect on the growth of seedlings, but nicotinic acid and nicotinamide significantly inhibited the growth of roots. Based on these findings, the role of trigonelline synthesis in mungbean seedlings is discussed.

UI	MeSH Term	Description	Entries
D009525	Niacin	A water-soluble vitamin of the B complex occurring in various animal and plant tissues. It is required by the body for the formation of coenzymes NAD and NADP. It has PELLAGRA-curative, vasodilating, and antilipemic properties.	Nicotinic Acid,3-Pyridinecarboxylic Acid,Enduracin,Induracin,Lithium Nicotinate,Niacin Aluminum Salt,Niacin Ammonium Salt,Niacin Calcium Salt,Niacin Cobalt (2+) Salt,Niacin Copper (2+) Salt,Niacin Hydrochloride,Niacin Iron (2+) Salt,Niacin Lithium Salt,Niacin Lithium Salt, Hemihydrate,Niacin Magnesium Salt,Niacin Manganese (2+) Salt,Niacin Potassium Salt,Niacin Sodium Salt,Niacin Tartrate,Niacin Tosylate,Niacin Zinc Salt,Nicamin,Nico-400,Nicobid,Nicocap,Nicolar,Nicotinate,Wampocap,3 Pyridinecarboxylic Acid,Aluminum Salt, Niacin,Hydrochloride, Niacin,Nico 400,Nico400,Nicotinate, Lithium,Potassium Salt, Niacin,Sodium Salt, Niacin,Tartrate, Niacin,Tosylate, Niacin
D000470	Alkaloids	Organic nitrogenous bases. Many alkaloids of medical importance occur in the animal and vegetable kingdoms, and some have been synthesized. (Grant & Hackh's Chemical Dictionary, 5th ed)	Alkaloid,Plant Alkaloid,Plant Alkaloids,Alkaloid, Plant,Alkaloids, Plant
D001693	Biological Transport, Active	The movement of materials across cell membranes and epithelial layers against an electrochemical gradient, requiring the expenditure of metabolic energy.	Active Transport,Uphill Transport,Active Biological Transport,Biologic Transport, Active,Transport, Active Biological,Active Biologic Transport,Transport, Active,Transport, Active Biologic,Transport, Uphill
D012639	Seeds	The encapsulated embryos of flowering plants. They are used as is or for animal feed because of the high content of concentrated nutrients like starches, proteins, and fats. Rapeseed, cottonseed, and sunflower seed are also produced for the oils (fats) they yield.	Diaspores,Elaiosomes,Embryos, Plant,Plant Embryos,Plant Zygotes,Zygotes, Plant,Diaspore,Elaiosome,Embryo, Plant,Plant Embryo,Plant Zygote,Seed,Zygote, Plant
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor
D018525	Germination	The initial stages of the growth of SEEDS into a SEEDLINGS. The embryonic shoot (plumule) and embryonic PLANT ROOTS (radicle) emerge and grow upwards and downwards respectively. Food reserves for germination come from endosperm tissue within the seed and/or from the seed leaves (COTYLEDON). (Concise Dictionary of Biology, 1990)	Germinations
D018548	Cotyledon	A part of the embryo in a seed plant. The number of cotyledons is an important feature in classifying plants. In seeds without an endosperm, they store food which is used in germination. In some plants, they emerge above the soil surface and become the first photosynthetic leaves. (From Concise Dictionary of Biology, 1990)	Coleoptile,Seed Leaf,Coleoptiles,Cotyledons,Seed Leaves,Leaf, Seed,Leave, Seed,Leaves, Seed,Seed Leave
D027805	Phaseolus	A plant genus in the family FABACEAE which is the source of edible beans and the lectin PHYTOHEMAGGLUTININS.	Bean, Kidney,Bean, Tepary,Kidney Bean,Tepary Bean,Common Bean Plant,French Bean Plant,Phaseolus acutifolius,Phaseolus vulgaris,Bean Plant, Common,Bean Plant, French,Bean Plants, Common,Bean Plants, French,Beans, Kidney,Beans, Tepary,Common Bean Plants,French Bean Plants,Kidney Beans,Phaseolus vulgari,Plant, Common Bean,Plant, French Bean,Plants, Common Bean,Plants, French Bean,Tepary Beans,vulgaris, Phaseolus