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Comparative study of metabolism and forms of transport of phosphate between Ascophyllum nodosum and Polysiphonia lanosa
Author(s) -
Penot Marthe,
Hourmant Annick,
Penot Michel
Publication year - 1993
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1993.tb01733.x
Subject(s) - ascophyllum , metabolism , thallus , uridine diphosphate , biochemistry , algae , botany , biology , hexose , chemistry , enzyme
Polysiphonia lanosa (L.) Tandy is a marine red alga that usually grows epiphytically on the fucale Ascophyllum nodosum (L.) Le Jolis. The present work was conducted in order to obtain more information on the relationships between these two algae, especially as regards the metabolism and long‐distance transport of phosphorus. Three types of experiments were carried out using labelled phosphorus. (1) Comparative study of the metabolism of 32 P 1 absorbed by the tissues of each species. By means of two‐dimensional chromatography and autoradiography, it was shown that 32 P 1 was rapidly incorporated into organic soluble compounds (adenosine triphosphate, hexose monophosphate, uridine diphosphoglucose, phosphoenolpyruvate + phosphoglyceric acid). Although the two algae belong to different phylae the phosphorylated compounds were not very different. The energy charges (0. 72 for both species) were in the usual range for aerobic plant tissues. On the other hand the incorporation of 32 P 1 into the insoluble P 0 fraction was doubled in P. lanosa compared to in A. nodosum (ca 80 and 40%, respectively). At the source level, the air bladder of A. nodosum. the same soluble compounds (inorganic phosphate, P 1 adenosine triphosphate, hexose monophosphate. etc.) represented the likely forms transported. A part of the soluble P 0 fraction may return to the P 1 fraction. (2) In translocation experiments conducted in situ, 32 P 1 locally injected into an air bladder moved over long distances not only through the thallus of A. nodosum but also into P. lanosa. The reciprocal transfer remained unsuccessful. (3) The 32 P 1 represented the predominant compound identified in the two species: this argues in favour of P 1 as the translocated form of phosphorus. Our results support the hypothesis of a parasitic rather than a simple epiphytic relationship between the two algae.