Action Spectrum of the Photoinduced Sexual Stage in the Fungus Nectria haematococca Berk. and Br. var cucurbitae (Snyder and Hansen) Dingley

Abstract

An action spectrum was determined for the photoinduced formation of perithecia in a homothallic strain of Nectria haematococca Berk. and Br. var. cucurbitae (Snyder and Hansen) Dingley. Dose-response curves for perithecial formation were obtained from 340 to 510 nanometers at 10-nanometer intervals. Radiation longer than 510 nanometers was not effective for inducing perithecial formation. The action spectrum indicated peaks of activity near 360, 440, and 480 nanometers with shoulders near 420 and 460 nanometers. Minima occurred near 350 nanometers, 390 to 410 nanometers, and 470 nanometers. The general shape of this action spectrum appears to be similar to those obtained for many different near ultraviolet-blue-sensitive organisms in which a flavoprotein molecule was postulated to be the photoreceptor.Previous research has shown that a photorequirement exists for proper development of asexual and sexual reproductive structures in several closely related strains of the fungus Nectria haematococca Berk. and Br. var. cucurbitae (Snyder and Hansen) Dingley (2,8,9,25,33 Baker (2) found that light intensity in particular had a marked effect on the production of the sexual (perithecia) stage. Of three intensities used, the optimal intensity for stimulating the production of perithecia in heterothallic strains was 190 to 195 ft-c.In a more comprehensive study of the light requirement, Curtis (8) found a broad optimal range of intensity for the production of perithecia from 50 to 250 ft-c. Darkness or higher intensities of irradiation greatly inhibited the formation of perithecial primordia and perithecia. In addition, a region of spectral sensitivity in the near UV-blue portion of the spectrum was found for two heterothallic strains and a homothallic strain.

Action Spectrum for Photosporogenesis in Botrytis cinerea Pers. ex Fr

“…Several action spectra have been reported for photoinduced sporulation for the near UV-blue group of fungi (1,3,5,7,13) and for the UV group (10,11,15). These fungi are in the Sphaeriales or they are Fungi Imperfecti usually associated with Sphaeriales in their perfect stage.…”

“…The similarity of these action spectra suggests FRONT SURFACE ALUMINUM MIRROR FIG. 1. Schematic representation of apparatus for monochromatic irradiation.…”

Photoreceptors for biosynthesis, energy storage and vision

“…The universality of such so-called blue-liglit responses is retnarkable, with examples being known among every type of organism: bacteria, protists, fungi, plants and anitnals. Such responses include phototropism in the sporangiophores of tlie fungi Phycotnyces (Curry & Gruen, 1959;Delbrtick & Shropshire, 1960) and Pilobolus (Page & Curry, 1966), in Avena (oat) seedlings (Shropsliire & Withrow, 1958;Thimann & Curry, 1961), and in growing tips of the alga Vaucheria geminata (Kataoka, 1975); piiototaxis in tlie protists Euglena (Dielm, 1969;Checcucci et al, 1976) and Nitzschia (Nultsch, 1971); stimulation of carotenoid synthesis in Mycobaeterium (Rillitig, 1964;Howes & Batra, 1970), and in the fungi Fusariwn (Rau, 1967), Neurospora (Zalokar, 1955;De Fabo, Harding & Shropshire, 1976) atid Phycotnyces (Bergtnan, Eslava & Cerda-Obnedo, 1973), enhancement of respiration of the alga Oilorella Kowallik, 1967;Pickett & French, 1967); entrainment of tlie circadian rhytluns of conidia formation in the fungus Neurospora (Sargent & Briggs, 1967) and of pupae etnergence in the fruit fly Drosophila (Frank & Zimmerman, 1969;Klemm & Ninnemann, 1976); chloroplast rearrangement in the moss Funaria (Zurzyeki, 1972); retardation of flower opening in the plant Oenothera lamarckiana (Saito & Yatnaki, 1967); and stimulation of sexual development in the fungus Nectria (Curtis, 1972), of eonidia formation In the fungus Triehoderma (Gressel & Hartmann, 1968) formation in the fungus Phycomyces (Bergtnan, 1972). Although the exaet wavelengths for the various tnaxitna in the action speetra vary sotnewhat from organistn to organistn (not surprisingly, sinee the various speetra were determined by different proeedures by different experimenters over a period of several decades) the shape is always the same (Fig.…”

Nectria haematococca mating population. VI. Cultural parameters affecting growth, conidiation, and perithecial formation

“…protoperithecia in the dark after a 4°C cold shock (3,35,36). Some homothallic strains of N. haematococca apparently do not require light for perithecium induction (20); however, Curtis (6,8) reported wavelength and photoperiodic effects on perithecial formation of such strains. N. haematococca M P V requires light for formation of the perfect stage, but the number of perithecia produced can be diminished by excess light, especially during the prespermatization growth phase (29).…”