A Survey of Acid-soluble Nucleotides in Rice Plants

[摘要] The extraction and measurement of acid-soluble nucleotides in rice plants were studied at their different growth stages. Nucleotides were separated by Dowex-1 anion exchange column chromatography followed by paper chromatography. About eleven peaks were detected on the extracts from all stages of growth by using the column chromatography. The peaks of nucleotides obtained were corresponded to AMP (peak II), UMP (IV), unidentified nucleotide (V), ADP (VI), UDPG (VII), ATP, UDP (VIII) and UTP (IX), respectively. Small quantities of cytidine and guanosine nucleotides were also detected. Peak II, corresponding to AMP, was the most abundant in the seedling stage. The level decreased gradually until 30 days before heading, but rose again toward the mature stage. Peak IV, corresponding to UMP, was not clear in the samples from the stage of seedling to 8 days after anthesis. But at the mature stage, the clear peak was obtained. Peak V, which had absorbance amximum at 236 mμ (at pH 2), wsa not yet identified. It gave values of 1.72, 0.24 and 0.10 for the absorbance ratios 250 mμ/260 mμ, 280 mμ/260mμ and 290 mμ/260mμ, respectively. There was a large amount of this compound in all growth stages except seedlings. Peak VI, which did not give a single peak, seemed to be due to ADP. Also smaller quantities of guanosine nucleotide and ADP-glucose might be contaminated. This peak increased with ripening. Peak VII, corresponding to UDPG, decreased toward the stage of maturity from the seedling stage. Peak VIII contained ATP with smaller quantities of UDP. This peak rose at the ripening stage, but decreased again at the maturity. It was confirmed that the relative value of each nucleotide is changed from the stage of seedling to maturity. The relationship of these results to the mechanism of ripening of rice plant is discussed.

[学科分类] 农业科学（综合）