The synergistic effect of drought and light stresses in sorghum and pearl millet. [Pennisetum glaucum; Sorghum bicolor]

Journal Article · Wed May 01 04:00:00 EDT 1991 · Plant Physiology; (United States)

DOI:https://doi.org/10.1104/pp.96.1.198· OSTI ID:7222663

Masojidek, M; Trivedi, S; Halshaw, L; Alexiou, A; Hall, D O ^[1]

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1. King's Coll. London (United Kingdom)

The effect of drought stress and high irradiance and their combination were studied under laboratory conditions using young plants of a very drought-resistant variety, ICMH 451, of pearl millet (Pennisetum glaucum) and three varieties of sorghum (Sorghum bicolor) - one drought-resistant from India, one drought-tolerant from Texas, and one drought-sensitive variety from France. CO{sub 2} assimilation rates and photosystem II fluorescence in leaves were analyzed in parallel with photosynthetic electron transport, photosystem II fluorescence, and chlorophyll-protein composition in chloroplasts isolated from these leaves. High irradiance slightly increased CO{sub 2} assimilation rates and electron transport activities of irrigated plants but not fluorescence. Drought stress (less than {minus}1 megapascal) depressed CO{sub 2} assimilation rates, fluorescence, and electron transport. Under the combined effect of drought stress and high irradiance, CO{sub 2} assimilation rates, fluorescence, and electron transport. Under the combined effects of drought stress and high irradiance, CO{sub 2} assimilation rates and fluorescence were severely inhibited in leaves, as were the photosynthetic electron transport. Under the combined effects of drought stress and high irradiance, CO{sub 2} assimilation rates and fluorescence were severely inhibited in leaves, as were the photosynthetic electron transport activities and fluorescence in chloroplasts (but not photosystem I activity). The synergistic or distinctive effect of drought and high irradiance is discussed. The experiments with pearl millet and three varieties of sorghum showed that different responses of plants to drought and light stresses can be monitored by plant physiological and biochemical techniques. Some of these techniques may have a potential for selection of stress-resistant varieties using seedlings.

• OSTI ID: 7222663
• Journal Information: Plant Physiology; (United States), Journal Name: Plant Physiology; (United States) Vol. 96:1; ISSN 0032-0889; ISSN PLPHA
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540110*
550500 -- Metabolism
59 BASIC BIOLOGICAL SCIENCES
BIOLOGICAL ADAPTATION
BIOLOGICAL EFFECTS
BIOLOGICAL STRESS
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CEREALS
CHALCOGENIDES
CHEMICAL REACTIONS
DROUGHTS
ELECTROMAGNETIC RADIATION
FLUORESCENCE
GRAMINEAE
LILIOPSIDA
LUMINESCENCE
MAGNOLIOPHYTA
MILLET
OXIDES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOSYNTHESIS
PLANTS
RADIATIONS
SENSITIVITY
SORGHUM
SYNERGISM
SYNTHESIS
VISIBLE RADIATION