Yield photosynthetic efficiency

If noncyclic photosynthetic electron transport leads to the translocation of 3 H /e and cyclic photosynthetic electron transport leads to the translocation of 2 H /A, what is the relative photosynthetic efficiency of ATP synthesis (expressed as the number of photons absorbed per ATP synthesized) for noncyclic versus cyclic photophosphorylation (Assume that the CFiCEq ATP synthase yields 1 ATP/3 H. )... 

J. S. Rocha, M. J. Barbosa, Wijffels (2001) Hydrogen production by photosynthetic bacteria culture media, yields and efficiencies, In Biohydrogen II. J. Miyake, T Matsunaga, A. San Pietro eds. Pergamon, Amsterdam 3-32... 

The acquisition of carbon is strongly modulated by the surface area of photosynthesizing leaves hence, understanding leaf area development is germane to efforts to increase yield. In many crops, biomass is linearly related to the amount of light intercepted (Monteith, 1977). This is certainly the case for Jerusalem artichoke, where total productivity is strongly correlated with the amount of solar radiation intercepted (Denoroy, 1996 Meijer et al., 1993). Leaf area, leaf duration, and photosynthetic efficiency of the crop canopy determine how much light is intercepted and subsequently utilized (Table 10.9). 

Table 1. Maximum daily growth yield and photosynthetic efficiency of CWoreWa sp. strain HA-1 in the cone-shaped helical tubular photobioreactor under field culture operation. ...

HYDROGEN PRODUCTION BY PHOTOSYNTHETIC BACTERIA CULTURE MEDIA, YIELDS AND EFFICIENCIES... 

Hydrogen Production by Photosynthetic Bacteria Culture Media, Yields and Efficiencies... 

The data show that SSHB increased the root dry matter in the same way it did in the other experiments. Simultaneously, we observed an increase in leaf length and leaf area which corresponded with an increase in invertase activity. The higher enzyme activity appeared to be the key to the whole problem. It is well known that acid invertase splits the disaccharide sucrose so that the two monosaccharides formed from it can become building stones for additional leaf substances. That is, glucose is recycled through the Embden-Meyerhof-Parnas pathway. Likewise, fructose is readily available for conversion into fructose 1,6-diphosphate. Subsequently, more leaf area arises which is able to produce more assimilates. The consequence is an increased yield. Thus, photosynthetic efficiency increases considerably. 

In wheat, the ear weights of both tillers and the main stem were increased, in comparison with untreated controls by brassinolide (BR) sprays (I). In corn, BR treatment had significant influence on the length of the unfertile tip portion of the ear and on the number of vacant kernels. The yield increased compared with untreated controls (2). Little is known of the effect of BR on the ripening of rice plants, and the mode of action of BR on the ripening of rice has not been studied. To increase crop yield, it is necessary to improve the photosynthetic efficiency and promote the translocation of photosynthetic products in the panicles. Therefore, we assessed the ripening of rice, the translocation of photosynthetic products, and plant hormone levels in panicles. 

Emerson R and Lewis CM (1942) The photosynthetic efficiency of phycocyanin in Chrococcus and the problem of carotenoid participation in photosynthesis. J Gen Physiol 25 579-595 Emerson R and Lewis CM (1943) The dependence of quantum yield of Chlorella photosynthesis on wavelength of light. Am J Bot 30 165-178... 

Photosynthesis typically only captures the energy from about 1% of incident light, leaving ample room for improvement of biomass yields, culture density, and growth rates. Several strategies for increasing photosynthetic efficiency have been employed in algae, as strains with modified photosynthetic apparatuses are quick to make and can be rapidly screened and characterized, at least compared to terrestrial plants. 

From Biomass Yield on Photons to Photosynthetic Efficiency... 

Table 1 Maximal Biomass Yield on Photons, and Maximal Photosynthetic Efficiency (PE) of Photoautotrophic Microalgal Growth Under Nutrient-Replete Conditions...

In this study, we show a linear relationship between ( IPS1 and (jlPS2 and the quantum yield of non-cyclic electron transport In leaves when photosynthetic efficiency varies with light Intensities. The results confirm that both the concentration of open PS2 reaction centres and their photochemical efficiency, which is modulated by non-photochemical processes associated with the antenna, determine j)PS2. 

During winter, high light and freezing temperatures interact to cause damage to photosynthesis of pine (1). The photochemicai efficiency of photosystem II (PS II), the quantum yield and the rate of light saturated photosynthesis are severely inhibited during natural winter conditions. Strand and Oquist (2, 3) have shown that winter stress of Scots pine involve both photoinhibition of photosystem II and frost inhibition of the enzymes in the Calvin cycle or the photophosphorylation. In the field it may take several months before full photosynthetic efficiency is restored after the winter (4, 5). 

Zhu, X.G., Long S.P. Ort D.R. (2010). Improving Photosynthetic Efficiency for Greater Yield. Annual Reoiao of Plant Biology, V0I61,0une 2010), pp. 235-261. 

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