Over-expressing the C3 photosynthesis cycle enzyme Sedoheptulose-1-7 Bisphosphatase improves photosynthetic carbon gain and yield under fully open air CO2fumigation (FACE)

Abstract Background Biochemical models predict that photosynthesis in C3 plants is most frequently limited by the slower of two processes, the maximum capacity of the enzyme Rubisco to carboxylate RuBP (Vc,max), or the regeneration of RuBP via electron transport (J). At current atmospheric [CO2] levels Rubisco is not saturated; consequently, elevating [CO2] increases the velocity of carboxylation and inhibits the competing oxygenation reaction which is also catalyzed by Rubisco. In the future, leaf photosynthesis (A) should be increasingly limited by RuBP regeneration, as [CO2] is predicted to exceed 550 ppm by 2050. The C3 cycle enzyme sedoheptulose-1,7 bisphosphatase (SBPase, EC 3.1.3.17) has been shown to exert strong metabolic control over RuBP regeneration at light saturation. Results We tested the hypothesis that tobacco transformed to overexpressing SBPase will exhibit greater stimulation of A than wild type (WT) tobacco when grown under field conditions at elevated [CO2] (585 ppm) under fully open air fumigation. Growth under elevated [CO2] stimulated instantaneous A and the diurnal photosynthetic integral (A') more in transformants than WT. There was evidence of photosynthetic acclimation to elevated [CO2] via downregulation of Vc,max in both WT and transformants. Nevertheless, greater carbon assimilation and electron transport rates (J and Jmax) for transformants led to greater yield increases than WT at elevated [CO2] compared to ambient grown plants. Conclusion These results provide proof of concept that increasing content and activity of a single photosynthesis enzyme can enhance carbon assimilation and yield of C3 crops grown at [CO2] expected by the middle of the 21st century. </jats:sec

Catecholamines are active plant-based drug compounds in Pisum sativum, Phaseolus vulgaris and Vicia faba Species

Introduction: Catecholamines (L-DOPA and dopamine) are the key metabolites found in nervous system and their endogenous deficiency is associated with different patho-physiological disorders. Therefore, it is important to screen the new herbal sources of catecholamines for drug preparation. In this study, the amount of L-DOPA and dopamine were investigated in the leaves and roots of three species from legume family such as Pisum sativum (garden pea), Phaseolus vulgaris (haricot bean) and Vicia faba (broad bean); using TLC and HPLC. Methods: The seeds of P. sativum, P. Vulgaris and V. faba were treated and cultured under the glasshouse conditions. The extraction from 1 gram of each plant sample was obtained and assayed for L-DOPA and dopamine using thin layer chromatography (TLC) and reversed-phase HPLC. Results: The results indicated that all cultivars accumulated different levels of L-DOPA and dopamine in leaves and roots. The quantitative results showed that the metabolites concentrations were high in the leaves of P. Sativum and V. faba compared to that in roots. Conclusion: The present study may provide a new avenue for preparation and estimation of L-DOPA and dopamine from plant sources and may be used for further analysis and therapeutic studies

Increased plastid transketolase activity in transgenic tobacco plants alters carbon metabolism and has negative impacts on growth and yield

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