This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Web of Science (16) Citing Articles via Google Scholar Google Scholar Articles by Kendrick, R. E. Articles by Spruit, C. J. P. Search for Related Content PubMed PubMed Citation Articles by Kendrick, R. E. Articles by Spruit, C. J. P. Agricola Articles by Kendrick, R. E. Articles by Spruit, C. J. P.

Articles

Phytochrome Properties and the Molecular Environment ¹

^a Laboratory of Plant Physiological Research, Agricultural University, Wageningen, The Netherlands

In vitro data support a scheme of phytochrome phototransformation involving intermediates in a sequential pathway. The fraction of total phytochrome maintained as intermediate under conditions of pigment cycling as well as the rate of the dark reversion of the far red-absorbing (Pfr) to the red-absorbing form of phytochrome (Pr) has been shown to depend on the molecular environment of the phytochrome molecules. Inverse dark reversion of Pr to Pfr has been observed in vitro. These results contribute toward an understanding of the observed paradoxes between physiological experiments and measurements of the amount and state of phytochrome in vivo. The in vivo spectrophotometric assay measures an average of the properties of phytochrome in different cellular environments, whereas a particular physiological response may be controlled by phytochrome molecules in one particular environment. It is therefore possible that all phytochrome is potentially active and triggers specific responses by virtue of its localization.

¹ This is the 333rd communication of this laboratory.