Topic
Emerson effect
About: Emerson effect is a research topic. Over the lifetime, 10 publications have been published within this topic receiving 455 citations.
Papers
TL;DR: The so-called chromatic transient, as observed after the replacement of illumination with light at 700 mu by illumination weith a shorter-wave light giving the same steady yield of photosynthesis, has the same action spectrum as the Emerson effect.
Abstract: Note: When Robert Emerson zvas killed in a plane accident on February 4. 1959, much of the experimental material accumulated in his two years work on the action spectrum of photosynthesis in the far-red region, remained unpublished. He zvas to present these results to the Botanical Congress in Montreal in August, 1959. Instead, the following paper was presented, prepared on the basis of Emerson's earlier talks and laboratory notes, and after consultation with his collaborators, R. V. Chalmers and C. Cederstrand. The theoretical discutssion of the results is my own. The presentation of this paper was intended as a memorial to Dr. Emerson; I was urged to publish it to give all those wvorking in the field access to the results of Emerson's last, exciting results. A paper presented by J. Myers (12) at the same mneeting provides both confirmation and interesting expansion of the phenomenon which is becoming knozwn as the Emerson effect*. In particular, it shows that the so-called chromatic transient, as observed after the replacement of illumination with light at 700 mu by illumination weith a shorter-wave light giving the same steady yield of photosynthesis, has the same action spectrum as the Emerson effect, i.e., suggests a specific role of chlorophyll b.-E. RABINOWITCH.
161 citations
TL;DR: The effects of red and far-red light on the fluorescence yield of chlorophyll a are thought to be another manifestation of the second Emerson effect.
77 citations
TL;DR: A peak is found at 670 mmu in the action spectrum of the "second Emerson effect" in the green alga Chlorella pyrenoidosa, and in the diatom Navicula minima; a shoulder appears in about the same location in the blue-green alga Anacystis nidulans and less clearly in the red alga Porphyridium cruentum.
73 citations
TL;DR: At sufficiently high densities of the filter solution, no measurable photosynthesis can be observed, although chlorophyll a molecules are still being excited at a significant rate, as can be proved by calculations from spectral distribution curves, and is confirmed by the occurrence of a "second Emerson effect" upon addition of orange light.
18 citations
TL;DR: Evidence is presented that the rate of photosynthesis at both wavelengths is enhanced, and the action spectra for the Emerson effect were determined by measuring the extra increase in photosynthesis obtained by adding light of various wavelengths to constant illumination of 700 mp.
Abstract: The investigations of two light reactions in photosynthesis driven by different pigment systems started with Emerson’s discovery that in the green alga Chlorella pyrenoidosa the rate of photosynthesis in light beams of 700 and 650 applied simultaneously, was higher than the sum of the rates in each beam separately (Emerson, Chalmers & Cederstrand 1957). This effect has been called ‘Emerson effect’ or ‘enhancement effect’. Since the quantum efficiency of light of 700 mp, compared with that of 650 mpwas rather low, the increase in rate in the two beams was attributed to an enhancement of the photosynthetic efficiency of light of 700 nip, by light of 650 mp. In this paper we will present evidence that the rate of photosynthesis at both wavelengths is enhanced. Action spectra for the Emerson effect were determined by measuring the extra increase in photosynthesis obtained by adding light of various wavelengths to constant illumination of 700 mp. The action spectrum for the Emerson effect in Chlorella showed maxima at 650 and 480 mp, which indicated that light absorbed by chlorophyll b was particularly effective in the enhancement. In the red alga Porphyridium cruentum photosynthesis brought about by light absorbed in the region around 680 mp was ‘enhanced’ by light absorbed by the phycobilins phycocyanin and phycoerythrin (Brody & Emerson 1959). It was concluded that efficient photosynthesis was only possible, if at least one of the accessory pigments was excited (Emerson et al. 1957; Brody & Emerson 1959).
17 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2014 | 1 |
| 1963 | 1 |
| 1962 | 2 |
| 1961 | 1 |
| 1960 | 5 |