The effect of nutrients on adenine nucleotide levels and the adenylate energy charge ratio in Spartina alterniflora and Spartina patens

Abstract. The response of the adenylate energy charge (AEC) ratio and the adenine nucleotide pools to nutrients was studied in two perennial marsh plant species. Adenine nucleotide levels and the AEC ratio were measured in Spartina patens (Alton) Muhl. plants which were grown in the greenhouse at various nutrient levels as well as in Spartina alterniflora Loisel. transplants removed from the field but maintained in marsh soil amended with different nutrient supplements. In addition, adenine nucleotide concentrations were measured in both species in their natural environment and compared with that of the same species grown in the greenhouse with a complement of nutrients.
The addition of nutrients stimulated an increase in the individual and total adenylate pools and the AEC ratio. Low nutrient levels resulted in extremely reduced adenylate pools. The AEC ratio was significantly affected in some instances, but did not decrease proportionately with the adenine nucleotide level and was typically maintained at values above 0.60. The adenine nucleotide concentrations measured in the leaves of both species were significantly higher in greenhouse-grown plants compared to field plants, but the AEC ratios were not significantly different.
Because the AEC ratio in plants can be significantly affected by nutrient level. AEC response in field investigations should be planned with attention to the potential effect of dissimilar nutrient levels among study sites.