Role of Carbohydrates in Diurnal Chilling Sensitivity of Tomato Seedlings
AUTOR(ES)
King, Ann I.
RESUMO
Tomato seedlings (Lycopersicon esculentum Mill.) chilled starting at different times during the light/dark cycle were most chilling-sensitive at the end of the dark period (AI King, MS Reid, BD Patterson 1982 Plant Physiol 70: 211-214). Low-temperature tolerance was regained with as little as 10 minutes of light exposure. Low light intensities were less effective than high light intensities in reducing sensitivity, and the length of exposure to light directly influenced sensitivity. Seedlings kept at low night temperatures prior to chilling were also less injured following chilling. Light also restored chilling tolerance to seedlings whose roots were removed. Supplying cut shoots with sucrose, glucose, or fructose reduced chilling sensitivity and largely eliminated the diurnal difference in sensitivity. Endogenous carbohydrate content was correlated with changes in chilling sensitivity; starch and sugar content fell markedly during the dark period. Increased concentrations of sugars were detected 15 minutes after the start of the light period. This evidence all suggests that changes in chilling sensitivity over the diurnal period are regulated by the light cycle. It also suggests that increased sensitivity at the end of the dark period could be due to carbohydrate depletion, and that chilling tolerance following light exposure is likely due to carbohydrate accumulation or closely related events.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1054566Documentos Relacionados
- Response to Chilling of Tomato Seedlings and Cells in Suspension Cultures
- Chilling Sensitivity of Cucumber Cotyledon Protoplasts and Seedlings 1
- Role of Catalase in Inducing Chilling Tolerance in Pre-Emergent Maize Seedlings.
- Evidence for Chilling-Induced Oxidative Stress in Maize Seedlings and a Regulatory Role for Hydrogen Peroxide.
- Reversibility of Chilling Injury to Corn Seedlings