Field Study of the Interaction between Solar Ultraviolet-B Radiation and Drought on Photosynthesis and Growth in Soybean

• Published in: Plant physiology (Bethesda) Vol. 92; no. 1; pp. 141 - 146
• Main Authors: Sullivan, Joe H., Teramura, Alan H.
• Format: Journal Article
• Language: English
• Published: Rockville, MD American Society of Plant Physiologists 01.01.1990
• Subjects: Agronomy. Soil science and plant productions; BASIC BIOLOGICAL SCIENCES; Biological and medical sciences; BIOLOGICAL EFFECTS; BIOLOGICAL STRESS; Carbon dioxide; CHEMICAL REACTIONS; Dehydration; Drought; DROUGHTS; Economic plant physiology; ELECTROMAGNETIC RADIATION; FAR ULTRAVIOLET RADIATION; FIELD TESTS; Fundamental and applied biological sciences. Psychology; GLYCINE HISPIDA; GROWTH; LEGUMINOSAE; MAGNOLIOPHYTA; MAGNOLIOPSIDA; Metabolism; Net assimilation, photosynthesis, carbon metabolism. Photorespiration, respiration, fermentation (anoxia, hypoxia); Nutrition. Photosynthesis. Respiration. Metabolism; PHOTOCHEMICAL REACTIONS; PHOTOSYNTHESIS; Photosynthesis, respiration. Anabolism, catabolism; PLANT GROWTH; Plant interaction; Plant physiology and development; PLANTS; RADIATIONS; Soil water; Solar radiation; Soybeans; SYNTHESIS; TESTING; ULTRAVIOLET RADIATION 551000 > Physiological Systems; Growth; Water potential; Glycine max; Field experiment; Stress; Ultraviolet radiation; Leguminosae; Vegetable crop; Seed yield; Dicotyledones; Angiospermae; Spermatophyta; Gas exchange; Photosynthesis; Drought
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.92.1.141

Soybean, Glycine max (L.) Merr. cv Essex, plants were grown in the field in a 2 × 2 factorial design, under ambient and supplemental levels of ultraviolet-B (UV-B) radiation (supplemental daily dose of 5.1 effective kilojoules per square meter) and were either well-watered or subjected to drought. Soil water potentials were reduced to -2.0 megapascals by the exclusion of natural precipitation in the drought plots and were maintained at approximately -0.5 megapascal by supplemental irrigation in well-watered plots. Plant growth and gas exchange characteristics were affected under both drought and supplemental UV-B radiation. Whole-leaf gas exchange analysis indicated that stomatal limitations on photosynthesis were only significantly affected by the combination of UV-B radiation and drought but substrate (ribulose bisphosphate) regeneration limitations were observed under either stress. The combined effect of both drought and UV-B radiation on photosynthetic gas exchange was a reduction in apparent quantum efficiency and the rapid appearance of biochemical limitations to photosynthesis concomitant with reduced diffusional limitations. However, the combination of stresses did not result in additive effects on total plant growth or seed yield compared to reductions under either stress independently.