Photosynthetic inhibition after long-term exposure to elevated levels of atmospheric carbon dioxide

✍ Scribed by Evan H. Delucia; Thomas W. Sasek; Boyd R. Strain

• Publisher: Springer
• Year: 1985
• Tongue: English
• Weight: 495 KB
• Volume: 7
• Category: Article
• ISSN: 0166-8595
• DOI: 10.1007/bf00037008

✦ Synopsis

The effect of long-term exposure to elevated levels of CO 2 on biomass partitioning, net photosynthesis and starch metabolism was examined in cotton. Plants were grown under controlled conditions at 350, 675 and 1000gll -~ CO 2. Plants grown at 675 and 1000 gl 1-~ had 72% and 115% more dry weight respectively than plants grown at 350~I1 '. Increases in weight were partially due to corresponding increases in leaf starch. CO 2 enrichment also caused a decrease in chlorophyll concentration and a change in the chlorophyll a/b ratio. High CO 2 grown plants had lower photosynthetic capacity than 350gll ~ grown plants when measured at each CO 2 concentration. Reduced photosynthetic rates were correlated with high internal (non-stomatal) resistances and higher starch levels. It is suggested that carbohydrate accumulation causes a decline in photosynthesis by feedback inhibition and/or physical damage at the chloroplast level.