Pyridine Nucleotides in Selected Plant Species Ecological and Evolutionary Aspects

Abstract

Summary The pyridine nucleotide levels and reduction charges in selected species of the plant kingdom are described. Data, determined in plants growing under natural conditions (without any treatment) are discussed from physiological and evolutionary aspects. The conclusions are based on the interpretation of data from representative plants of 40 species, using own results of 17 species and data from literature. The results show the existence of special proportions within the pyridine nucleotide system of plants — independent of their evolution level and the metabolic pathway which is mainly responsible for energy supply (ARC > CRC; ARC ≥ 0.5). The NADP(H)/NAD(H) ratio of heterotrophic systems is lower than 1, whereas autotrophic systems show a ratio of 1 or higher. Possibly, NADP(H)/NAD(H) ratios higher than 3 indicate C4-and CAM-NADP-ME types of CO2 fixation. Anaerobic growth leads to an increase in the catabolic reduction charge (CRC ≥ 0.5), whereas a CRC lower than 0.5 is typical of plants under normoxia. A low reduction charge (RC