Inhibition of seagrass photosynthesis by ultraviolet-B radiation

Journal Article · Wed Jul 01 04:00:00 EDT 1981 · Plant Physiol.; (United States)

DOI:https://doi.org/10.1104/pp.68.1.74· OSTI ID:6120647

Trocine, R P; Rice, J D; Wells, G N

Effects of ultraviolet-B radiation on the photosynthesis of seagrasses (Halophila engelmanni Aschers, Halodule wrightii Aschers, and Syringodium filiforme (Kuetz) were examined. The intrinsic tolerance of each seagrass to ultraviolet-B, the presence and effectiveness of photorepair mechanisms to ultraviolet-B-induced photosynthetic inhibition, and the role of epiphytic growth as a shield from ultraviolet-B were investigated. Halodule was found to possess the greatest photosynthetic tolerance for ultraviolet-B. Photosynthesis in Syringodium was slightly more sensitive to ultraviolet-B while Halophila showed relatively little photosynthetic tolerance. Evidence for a photorepair mechanism was found only in Halodule. Syringodium appeared to rely primarily on a thick epidermal cell layer to reduce photosynthetic damage. Halophila seemed to have no morphological or photorepair capabilities to deal with ultraviolet-B. This species appeared to rely on epiphytic and detrital shielding and the shade provided by other seagrasses to reduce ultraviolet-B irradiation to tolerable levels. The presence of epiphytes on leaf surfaces was found to reduce the extent of photosynthetic inhibition from ultraviolet-B exposure in all species. Halophila appears to obtain an increased photosynthetic tolerance to ultraviolet-B as an indirect benefit of chloroplast clumping to avoid photo-oxidation by intense levels of photosynthetically active radiation.

• Research Organization: Florida Inst., of Tech., Melbourne
• OSTI ID: 6120647
• Journal Information: Plant Physiol.; (United States), Journal Name: Plant Physiol.; (United States) Vol. 68:1; ISSN PLPHA
• Country of Publication: United States
• Language: English

Related Subjects

500200 -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
560113 -- Radiation Effects on Biochemicals-- In Plants-- (-1987)
560141* -- Radiation Effects on Plants-- Basic Studies-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AQUATIC ECOSYSTEMS
BENCH-SCALE EXPERIMENTS
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
CHEMICAL REACTIONS
CHRONIC EXPOSURE
CHRONIC IRRADIATION
COASTAL REGIONS
COMPARATIVE EVALUATIONS
ECOSYSTEMS
ELECTROMAGNETIC RADIATION
GRASS
INHIBITION
IRRADIATION
LEAVES
NEAR ULTRAVIOLET RADIATION
PHOTOCHEMICAL REACTIONS
PHOTOSYNTHESIS
PLANTS
RADIATION EFFECTS
RADIATIONS
RADIOSENSITIVITY
RECOVERY
REPAIR
SYNTHESIS
ULTRAVIOLET RADIATION