Purine and pyrimidine nucleotide metabolism in higher plants

Genetic and molecular characterization reveals a unique nucleobase cation symporter 1 in Arabidopsis

“…A further trait in nucleobase biochemistry is the high degree of compartmentalization, necessitating extensive intra-and inter-cellular transport. A prime example is the essential interplay of nucleobase biochemical pathways in seed germination and early seedling development necessitating both intercellular transport of metabolites from endosperm to cotyledons as well as intracellular transport between organelles [1][2][3][4][5][6][7]. This highly involved nucleobase transport serves the numerous needs for nucleobases in plants and stands in contrast to nucleobase transport in microbes that mainly serves salvaging of external nitrogen sources.…”

Dual function of pyrimidine metabolism in potato (Solanum tuberosum) plants: pyrimidine salvage and supply of β‐alanine to pantothenic acid synthesis

“…Although no data have been published about the source-sink transport of nucleosides or nucleobases in plants, Kombrink and Beevers (1983) reported the transport of pyrimidine nucleosides from endosperm to cotyledons in germinating castor bean seedlings. High pyrimidine salvage activity in tubers may be to maintain sufficient nucleotides for cell division and enlargement in growing potato tubers (Stasolla et al 2003). The low pyrimidine degradation activity in tubers suggests that pantothenic acid is not synthesized via uracil in tubers.…”

“…Pyrimidine salvage may contribute to the turnover of pyrimidine nucleotides in potato plants, as in many other organisms (Stasolla et al 2003).…”

“…These results suggest that uridine and cytidine, originally produced as catabolites of pyrimidine nucleotides, are utilized for the regeneration of pyrimidine nucleotides in potato plants. A part of the nucleosides is catabolized by the pyrimidine reduction pathway in plants (Stasolla et al 2003). Uridine is initially hydrolysed to uracil, which enters the catabolic pathway.…”

Heterologous complementation studies reveal the solute transport profiles of a two-member nucleobase cation symporter 1 (NCS1) family in Physcomitrella patens

“…This metabolic complexity reflects the extensive requirements for nucleobases throughout the plant life cycle including; continual DNA and RNA synthesis and salvage, nitrogen storage in endosperm and release upon germination, nitrogen acquisition and long-distance transport exemplified by the ureide cycle and production of cytokinins and purine alkaloids (Stasolla et al, 2003;Ashihara et al, 2008;Fr ebort et al, 2011;Collier and Tegeder, 2012). Nucleobase biochemistry utilizes multiple subcellular compartments within cells, between adjacent cells or between tissues -necessitating a robust membrane transporter system to move intermediates.…”