Growth, photosynthesis, and metabolism of sugar beet at an early stage of exposure to elevated CO2

Abstract

The effects of ëé 2 concentration ( C ‡ ) on growth, photosynthesis, and the activity of enzymes associated with the translocation and assimilation of ëé 2 were studied in sugar beet ( Beta vulgaris L. subsp. saccharifera , cv. Ramonskaya) plants. The plants were grown in controlled-climate chamber to the stage of 3 − 4 leaves and then used in experiments. Experimental plants were exposed in boxes to doubled C ‡ (700 µ l/l, 2C plants), whereas control plants were kept in a chamber with ambient atmosphere (350 µ l/l, 1C plants). As compared with 1C plants, in 3 and 8 days, the leaf area of 2C plants increased by 14 and 26%, respectively. The rate of their photosynthesis ( P n ) measured in 3, 6, and 8 days increased by 85, 47, and 52%, respectively, whereas in normal air, the values of P n in 2C plants were by 12, 19, and 15% lower than in 1C plants. After 8-day growth, the content of soluble carbohydrates in the leaves of 2C plants attained 7.2%, being by 80% greater than in 1C plants; the content of starch did not exceed 3%. The total content of chlorophylls a and b in the leaves of 2C plants was by 14% greater than in 1C plants, but their ratio was essentially the same. The level of protein in 2C plants was by 13.4% lower than in 1C plants. The activity and content of Rubisco in 1C and 2C plants were similar. As compared with 1C plants, in 2C plants the activity of soluble carbonic anhydrase (sCA) was lower by 34% in 3 days and by 18% in 8 days; the activity of carbonic anhydrase of membrane preparations (mCA), was lower by 24 and 77%, respectively. Catalase activity in 2C plants became by 8% lower than in 1C plants only after 8 days. A reduction in the photosynthetic ability of 2C plants in ambient atmosphere, a decrease in activity of sCA and, especially, of mCA observed together with invariable activity and content of Rubisco in the leaf extracts are interpreted as early symptoms of acclimation of youn g plants of sugar beet to elevated ëé 2 .Abbreviations : C a -atmospheric concentration of CO 2 ; 1C and 2C -plants grown in normal atmosphere and at a doubled C a , respectively; mCA-membrane-bound carbonic anhydrase; ME-2-mercaptoethanol; PMSF-phenylmethylsulfonyl fluoride; P n -the rate of photosynthesis; PVP-polyvinylpyrrolidone; sCA-soluble carbonic anhydrase.

10.1007/s11183-008-2006-z

“…Low level of (sC-Glu) in control leaves (without incubation) in early SVG agrees with the results obtained for the young plants of sugar beet and published earlier [11]. An increase in Glu level in nonincubated leaves was a specific age characteristic of carbohydrate balance in different periods of SVG.…”

“…saccharifera [11]. In order to avoid major hormonal rearrangements of the metabolism associated with the transition to flowering, we investigated the effect of the elevated [CO 2 ] on growth, photosynthesis, and activity of the enzymes directly or indirectly related to the assimilation of CO 2 (Rubisco and sCA) in the stage of vegetative growth (SVG) of sugar beet Beta vulgairs , subsp.…”

“…In order to avoid major hormonal rearrangements of the metabolism associated with the transition to flowering, we investigated the effect of the elevated [CO 2 ] on growth, photosynthesis, and activity of the enzymes directly or indirectly related to the assimilation of CO 2 (Rubisco and sCA) in the stage of vegetative growth (SVG) of sugar beet Beta vulgairs , subsp. However, in normal atmosphere, P n of plants adapted to elevated [CO 2 ] decreased; sCA activity showed a slight but statistically reliable decline [11]. Sugar beet is notable for the essential lack of delay in growth and suppression of photosynthesis upon the accumulation of very high levels of carbohydrates in the leaves [12].…”

Removal of Low-Molecular Weight Aldehydes by Selected Houseplants under Different Light Intensities and CO2 Concentrations

“…The CO2 experiment results could be explained by the fact that plants exposed to high CO2 may make adaptive acclimatization response in terms of photosynthesis, stomatal conductance, water use efficiency, and production allocation etc. [37,38]. Stomatal movements are primarily in response to the changes from environmental parameters such as light and CO2 concentration [50].…”

Cash Crop Halophytes: The Ecologically and Economically Sustainable Use of Naturally Salt-Resistant Plants in the Context of Global Changes

“…It leads to a higher CO 2 concentration gradient between the outside air and the intercellular spaces of the leaves, so that the diffusion of CO 2 into the leaves and the pCO 2 /pO 2 ratio at the sites of photoreduction are increased (Robredo et al 2007 ). Therefore, usually photorespiration and the rates of oxygen activation and ROS formation are reduced due to an increased NADPH utilisation, whereas the net photosynthetic rate and thus the carbon supply are enhanced (Kirschbaum 2004 ;Ignatova et al 2005 ;Pérez-López et al 2012 ;Wang et al 2012 ). Furthermore, we often fi nd a lower stomatal resistance (Li et al 2003 ;Rogers et al 2004 ), which, together with higher net assimilation, also leads to a better water use effi ciency of photosynthesis (Morgan et al 2001 ;Urban 2003 ).…”