Effects of a short-term shift to low temperature and of long-term cold hardening on photosynthesis and ribulose-1,5-bisphosphate carboxylase/oxygenase and sucrose phosphate synthase activity in leaves of winter rye (Secale cereale L.)

• Published in: Plant physiology (Bethesda) Vol. 106; no. 3; pp. 983 - 990
• Main Authors: Hurry, V.M. (Australian National University, Canberra ACT, Australia), Malmberg, G, Gardestrom, P, Oquist, G
• Format: Journal Article
• Language: English
• Published: Rockville, MD American Society of Plant Physiologists 01.11.1994
• Subjects: Acclimatization; ACTIVIDAD ENZIMATICA; ACTIVITE ENZYMATIQUE; Adaptation to environment and cultivation conditions; Agronomy. Soil science and plant productions; Biological and medical sciences; Carbon dioxide; Cold hardening; DURCISSEMENT; ENDURECIMIENTO; Environmental and Stress Physiology; Enzymes; FEUILLE; FOTOSINTESIS; FRIO; FROID; Fundamental and applied biological sciences. Psychology; GEL; Genetics and breeding of economic plants; GLICOSILTRANSFERASAS; GLYCOSYLTRANSFERASE; HELADA; HOJAS; Leaves; Low temperature; METABOLISME; METABOLISMO; Phosphates; PHOTOSYNTHESE; Photosynthesis; Physical agents; Plant physiology and development; Plants; RESISTANCE A LA TEMPERATURE; RESISTENCIA A LA TEMPERATURA; RIBULOSA-BIFOSFATO CARBOXILASA; RIBULOSE-BISPHOSPHATE CARBOXYLASE; RITMOS BIOLOGICOS; Rye; RYTHME BIOLOGIQUE; SECALE CEREALE; TEMPERATURA; TEMPERATURE; Varietal selection. Specialized plant breeding, plant breeding aims; Vegetative apparatus, growth and morphogenesis. Senescence; Short term; Monocotyledones; Secale cereale; Cold; Enzyme; Transferases; Glycosyltransferases; Ribulose-bisphosphate carboxylase; Lyases; Plant leaf; Sucrose-phosphate synthase; Long term; Cereal crop; Stress; Carbon-carbon lyases; Gramineae; Carboxy-lyases; Angiospermae; Hexosyltransferases; Spermatophyta; Gas exchange; Photosynthesis; Adaptation; Frost resistance
• DOI: 10.1104/pp.106.3.983
• ISSN: 0032-0889

The effect of a short-term (hours) shift to low temperature (5 degrees C) and long-term (months) cold hardening on photosynthesis and carbon metabolism was studied in winter rye (Secale cereale L. cv Musketeer). Cold-hardened plants grown at 5 degrees C exhibited 25% higher in situ C02 exchange rates than nonhardened plants grown at 24 degrees C. Cold-hardened plants maintained these high rates throughout the day, in contrast to nonhardened plants, which showed a gradual decline in photosynthesis after 3 h. Associated with the increase in photosynthetic capacity following cold hardening was an increase in ribulose-1,5-bisphosphate carboxylase/oxygenase and sucrose phosphate synthase adivity and 3- to 4-fold increases in the pools of associated metabolites. Leaves of nonhardened plants shifted overnight to 5 degrees C required 9 h in the light at 5 degrees C before maximum rates of photosynthesis were reached. The gradual increase in photosynthesis in leaves shifted to 5 degrees C was correlated with a sharp decline in the 3-phosphoglycerate/triose phosphate ratio and by an increase in the ribulose bisphosphate/3-phosphoglycerate ratio, indicating the gradual easing of aninorganic phosphate-mediated feedback inhibition on photo-synthesis. We suggest that the strong recovery of photosynthesis in winter rye following cold hardening indicates that the buildup of photosynthetic enzymes, as well as those involved in sucrose synthesis, is an adaptive response that enables these plants to maximize the production of sugars that have both cryoprotedive and storage functions that are critical to the performance of these cultivars during over-wintering