Carbon metabolite feedback regulation of leaf photosynthesis and ..

Alterations in photosynthesis, leaf conductance, translocation, and ultrastructure

Cotton Leaf Photosynthesis and Carbon Metabolism.

Respiration refers to the metabolism of oxygen and the release of carbon dioxide. In it is a positive term, a process vital to life. But photorespiration is an entirely negative term because it represents a severe loss to the process of using light energy in photosynthetic organisms to fix carbon for subsequent carbohydrate synthesis. By leading to the loss of up to half of the carbon that has been fixed at the expense of light energy, photorespiration undoes the work of photosynthesis.

It is also important to develop the potential photosynthetic capacity of non-leaf green organs.

Cotton leaf photosynthesis and carbon metabolism

[27]Bondada B R, Oosterhuis D M, Murphy J B, Kim K S. Effect of water stress on the epicuticular wax composition and ultrastructure of cotton leaf, bract, and boll. Environ Exp Bot, 1996, 36:61–69

On the contribution of panicle photosynthesis to grain yield in rice plants.

[15]Tambussi E A, Bort J, Guiamet J J, Nogues S, Araus J L. The photosynthetic role of ears in C3 cereals:metabolism, water use efficiency and contribution to grain yield. Plant Sci, 2007, 26:1–16

Chlorophylls and carotenoids: pigments of photosynthetic biomembranes.


Cotton leaf photosynthesis and carbon metabolism.

The connection to hot and dry conditions comes from the fact that all the plants will close their stomata in hot and dry weather to conserve moisture, and the continuing fixation of carbon from the air drops the CO2 dramatically from the atmospheric concentration of nominally 380 ppm (2004 value). If the CO2 compensation point is lower on the above scale, the plant can operate in hotter and dryer conditions. The limits are placed by the fact that begins to fix oxygen rather than CO2, undoing the work of photosynthesis. C4 plants shield their rubisco from the oxygen, so can operate all the way down to essentially zero CO2 without the onset of photorespiration.

Cotton Leaf Photosynthesis and Carbon ..

Theoretical responses of C3 and C4 photosynthesis to rising atmospheric carbon dioxide (a); and identification of biochemical limitations associated with feedback inhibition in the photosynthetic response of C3 species to rising CO2 (b). Adapted from Sage and Coleman, . With permission from US Government.

related to photosynthesis specially carbon fixation were ..

N2 - The effect of long-term exposure to elevated levels of CO2 on biomass partitioning, net photosynthesis and starch metabolism was examined in cotton. Plants were grown under controlled conditions at 350, 675 and 1000 μl l-1 CO2. Plants grown at 675 and 1000 μl l-1 had 72% and 115% more dry weight respectively than plants grown at 350 μl l-1. Increases in weight were partially due to corresponding increases in leaf starch. CO2 enrichment also caused a decrease in chlorophyll concentration and a change in the chlorophyll a/b ratio. High CO2 grown plants had lower photosynthetic capacity than 350 μl l-1 grown plants when measured at each CO2 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.

on photosynthesis and general carbon metabolism ..

AB - The effect of long-term exposure to elevated levels of CO2 on biomass partitioning, net photosynthesis and starch metabolism was examined in cotton. Plants were grown under controlled conditions at 350, 675 and 1000 μl l-1 CO2. Plants grown at 675 and 1000 μl l-1 had 72% and 115% more dry weight respectively than plants grown at 350 μl l-1. Increases in weight were partially due to corresponding increases in leaf starch. CO2 enrichment also caused a decrease in chlorophyll concentration and a change in the chlorophyll a/b ratio. High CO2 grown plants had lower photosynthetic capacity than 350 μl l-1 grown plants when measured at each CO2 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.