Plant Nucleotide Metabolism. Hiroshi Ashihara

of major purine, pyrimidine, and pyridine nucleotides in plants are summarized. For comparison, cytokinins and nucleotide alkaloids are also noted. In most plants, the concentration of nucleotides is higher than nucleosides and bases. Cytokinins occur in much lower amounts than purine nucleotides. A much higher concentration of caffeine is found in tea and coffee plants.

References

      1 Ashihara, H. and Crozier, A. (1999). Biosynthesis and catabolism of caffeine in low-caffeine-containing species of Coffea. J. Agric. Food. Chem. 47: 3425–3431.

      2 Ashihara, H., Yabuki, N., and Mitsui, K. (1990). A high-performance liquid chromatography method for separation of purine bases, nucleosides and ureides: application to studies on purine catabolism in higher plants. J. Biochem. Biophys. Methods 21: 59–63.

      3 Ashihara, H., Ludwig, I., Katahira, R. et al. (2015). Trigonelline and related nicotinic acid metabolites: occurrence, biosynthesis, taxonomic considerations, and their roles in planta and in human health. Phytochem. Rev. 14: 765–798.

      4 Ashihara, H., Mizuno, K., Yokota, T., and Crozier, A. (2017). Xanthine alkaloids: occurrence, biosynthesis, and function in plants. In: Progress in the Chemistry of Organic Natural Products, vol. 105 (eds. A.D. Kinghorn, H. Falk, S. Gibbons and J. Kobayashi), 1–88. Cham: Springer International Publishing.

      5 Ashihara, H., Stasolla, C., Fujimura, T., and Crozier, A. (2018). Purine salvage in plants. Phytochemistry 147: 89–124.

      6 Atkinson, D.E. (1977). Cellular Energy Metabolism and its Regulation. New York: Academic Press.

      7 Bishop, G., Sakakibara, H., Seo, M., and Yamaguchi, S. (2015). Biosynthesis of hormones. In: Biochemistry and Molecular Biology of Plants, 2e (eds. B.B. Buchanan, W. Gruissem and R.L. Jones), 769–833. Chichester, UK: Wiley.

      8 Brown, E. (1963). Purine and pyrimidine derivatives in mature pea seeds. Biochem. J. 88: 498–504.

      9 Crozier, A., Kamita, Y., Bishop, G., and Yokota, T. (2000). Biosynthesis of hormones and elicitor molecules. In: Biochemistry and Molecular Biology of Plants (eds. B.B. Buchanan, W. Gruissen and R.L. Jones), 850–829. Rockville: American Society of Plant Physiologists.

      10 Grzelczak, Z. and Buchowicz, J. (1975). Purine and pyrimidine bases and nucleosides of germinating Triticum aestivum seeds. Phytochemistry 14: 329–331.

      11 Hagedorn, P.H., Flyvbjerg, H., and Møller, I.M. (2004). Modelling NADH turnover in plant mitochondria. Physiol. Plant 120: 370–385.

      12 Henderson, J.F. and Paterson, A.R.P. (1973). Nucleotide Metabolism – an Introduction. New York: Academic Press.

      13 Kasimova, M.R., Grigiene, J., Krab, K. et al. (2006). The free NADH concentration is kept constant in plant mitochondria under different metabolic conditions. Plant Cell 18: 688–698.

      14 Noctor, G., Hager, J., and Li, S. (2011). Biosynthesis of NAD and its manipulation in plants. In: Advances in Botanical Research, vol. 58 (eds. R. Fabrice and D. Roland), 153–201. Academic Press.

      15 Novák, O., Hauserová, E., Amakorová, P. et al. (2008). Cytokinin profiling in plant tissues using ultra-performance liquid chromatography–electrospray tandem mass spectrometry. Phytochemistry 69: 2214–2224.

      16 Oikawa, A., Matsuda, F., Kikuyama, M. et al. (2011). Metabolomics of a single vacuole reveals metabolic dynamism in an alga Chara australis. Plant Physiol. 157: 544–551.

      17 Queval, G. and Noctor, G. (2007). A plate reader method for the measurement of NAD, NADP, glutathione, and ascorbate in tissue extracts: application to redox profiling during Arabidopsis rosette development. Anal. Biochem. 363: 58–69.

      18 Riondet, C., Morel, S., and Alcaraz, G. (2005). Determination of total ribonucleotide pool in plant materials by high-pH anion-exchange high-performance liquid chromatography following extraction with potassium hydroxide. J. Chromatogr. A 1077: 120–127.

      19 Saitoh, F., Noma, M., and Kawashima, N. (1985). The alkaloid contents of sixty Nicotiana species. Phytochemistry 24: 477–480.

      20 Sawert, A., Backer, A.I., and Wagner, K.G. (1988). Age-dependent decrease of nucleoside pools in cereal leaves. Plant Cell Physiol. 29: 61–65.

      21 Shimano, F. and Ashihara, H. (2006). Effect of long-term phosphate starvation on the levels and metabolism of purine nucleotides in suspension-cultured Catharanthus roseus cells. Phytochemistry 67: 132–141.

      22 Wagner, K.G. and Backer, A.I. (1992). Dynamics of nucleotides in plants studied on a cellular basis. In: International Review of Cytology, vol. 134 (eds. K.W. Jeon and M. Friedlander), 1–84. San Diego: Academic Press.

      23 Wang, G. and Pichersky, E. (2007). Nicotinamidase participates in the salvage pathway of NAD biosynthesis in Arabidopsis. Plant J. 49: 1020–1029.

      24 Yokozawa, T. and Oura, H. (1986). Contents of free adenine in soybeans from several countries. Agric. Biol. Chem. 50: 1317–1319.

3 General Aspects of Nucleotide Biosynthesis and Interconversions

3.1 Introduction

      This chapter focuses on (i) an outline of the formation of purine, pyrimidine, and pyridine ribonucleoside monophosphates from small molecular weight precursors, the initial metabolites of de novo nucleotide biosynthesis, (ii) conversion of these initial metabolites to nucleoside di- and triphosphates, and (iii) synthesis of deoxyribonucleotides from ribonucleotides. The biosynthesis of purine, pyrimidine, and pyridine monophosphate utilizes three distinct pathways. The individual pathways are presented in more detail in Part II (purine), Part III (pyrimidine), and Part VI (pyridine). In contrast, pathways ii and iii both involve common interconversions of purine and pyrimidine nucleotides, and are therefore, described in this chapter.

3.2 De Novo Biosynthesis of Ribonucleoside Monophosphates

In many organisms including plants, ribonucleotides are synthesized from precursors derived from amino acids, sugar phosphates, and carbon dioxide. De novo synthesis of purine, pyrimidines, and the ring of pyridine (nicotinamide adenine) nucleotides are synthesized via three distinct pathways. It is noteworthy that the initial products are nucleotides, namely inosine-5′-monophosphate (IMP), orotidine-5′-monophosphate (OMP) and nicotinate mononucleotide (NaMN), but not nucleosides or nucleobases. The de novo pathways of nucleotide biosynthesis are summarized in Figure 3.1. In the case of purine nucleotides, IMP is synthesized from 5-phosphoribosyl-1-pyrophosphate (PRPP) (Figure 3.1a). The carbon and nitrogen atoms of the purine ring come from multiple sources. Glycine contributes all its carbon and nitrogen atoms (positions 4, 5, and 7 of a purine ring), with additional nitrogen atoms from glutamine (positions 3 and 9) and aspartate (position 1), and further carbon atoms from formyl groups (positions 2 and 8), which are transferred from the coenzyme tetrahydrofolate as 10-formyltetrahydrofolate, and a carbon atom from bicarbonate (position 6). A detailed biochemical and molecular analysis of purine biosynthesis in plants has yet to be carried out, but the enzymatic steps are similar to those occurring in microorganisms and animals. More details of the 14 enzymatic steps involved in adenosine monophosphate (AMP) and GMP production from PRPP are presented in Part II.

Скачать книгу