Plant Nucleotide Metabolism. Hiroshi Ashihara

59 9 33 — 55 14 16 12 GTP 26 tr 23 tr 24 tr 26 26 8 GDP — — — — — — tr 3 3 GMP tr 9 tr — 10 — tr 3 2 IMP — 8 — 20 — 20 — — — XMP — — — — — — 29 — — UTP 18 20 49 7 27 6 88 55 10 UDP tr 18 — 23 59 16 46 29 22 UMP 178 81 187 74 174 50 55 33 24 CTP 9 tr 4 12 — — tr 7 2 CDP tr — — 9 — — tr 4 2 CMP — tr — tr — tr 32 6 3 Relative rate ΣAN (%) 44 56 35 42 44 60 48 45 40 ΣGN (%) 6 3 6 0 7 0 6 11 10 ΣUN (%) 48 38 59 42 50 0 40 39 44 ΣCN (%) 2 0 1 8 0 32 7 6 6 Energy status EC 0.85 0.45 0.91 0.57 0.92 0.48 0.86 0.81 0.60 ATP/ADP 7.6 0.5 14.9 2.0 5.1 1.7 3.3 5.6 1.4

      The values (nmol g⁻¹ f.w.) are obtained from the suspension-cultured cells at the exponential phase of growth and young leaves. For comparison, the values from phosphate-deficient Catharanthus roseus cells are also shown. tr: trace and EC: energy charge.

There are similar profiles of nucleotide pools in almost all plants. The pools of adenine nucleotides and uridine nucleotides (aka uracil nucleotides) always exceed the guanine nucleotide pool. The cytidine nucleotide pool is the smallest of these pools. The nucleoside triphosphate levels are usually much more substantial than those of nucleoside mono- and diphosphates.

The intracellular levels of nucleotides in plant cells are influenced by several environmental factors. For example, Pi starvation