| Description |
1 online resource |
| Contents |
Chapter Synechococcus Thermosynechococcus -- subsequently, by Kamiya and Shen (2003) in level (Rhee 2001). Also, x-ray crystallographic analysis is still not sufficient still low for the determination of side chains of amino-acid residues, most -- chapter Chlamydomonas Synechococcus Chlamydomonas -- complex from spinach. Further, the dimeric and also similar in several structural features of OEC subunits to -- chapter 2 Photoinhibit ion -- chapter Arabidopsis Dunaliella salina. A -- study has clearly established that the 23 kDa Dl fragment shows a FtsH dependent protein degradation. This study also suggested that besides FtsH, there may exist other proteases which may also be involved subsequently. -- chapter Arabidopsis ihaliana -- which is participates in the cpSRP dependent protein targeting to thylakoid membranes (Kogata et al., 1999) presumably the LHCP to the thylakoid membrane. -- chapter 3 Photoprotection -- chapter 3 4A. A Reactive Oxygen Species (ROS) : Production of Active Oxygen -- (Garcia -Plazaola et al., 2003) has relative significance of the VAZ cycle and that of lutein epoxide cycle in relation to energy dissipation. -- chapter (Citrulus lanatus) -- leaves, the total electron flux in PS existence of an alternative electron flux was suggested. The alternate flux -- chapter ApH dependent control than electron transport to oxygen in Mehler Arabidopsis -- Mehler reaction, together with photorespiration, is perhaps required to balance the electron transport chain and permit cyclic electron transport Among the photoprotective measures, the process of state transition -- chapter 4 Leaf Heliotropism, Solar Tracking and Regulation of Light Interception -- chapter The phenomenon of solar tracking is known from the early studies of Yin (1938) and that it is a blue light response, while the actual photoreceptors involved are not identified (Batschauer 1998; Briggs and Christie, 2002). In view of the fact that solar tracking behaviour results from light-driven turgor changes in the volume of the cells just as in the case of stomatal guard cells, the phototropins might be involved here also (Briggs and Christie, 2002). Sakamoto and Briggs (2002) have suggested that solar tracking may involv e phototropins. The precise molecular mechanisms concernin g the heliotropic movements are not currently known, while some knowledge is available on the mechanism of nyctinastic movements. However, Cronlund and Forseth (1995) have studied the mechanism of soybean leaflet movement and concluded that the mechanism of heliotropic movement was similar to that of nyctinastic movements. These authors have studied the role of K+ channels and the plasma membrane H/ATPase (Michelet and Boutry, 1995) in paraheliotropic movements throug h the measurements of leaf movements after treatment of pulvinus with promoters and inhibitors of HATPase and K+ channels. HATPase inhibition reduced the leaf -- chapter 5 Acclimation of Photosynthesis to Light Environment -- chapter Em̃s) was a two-pronged response. One of those responses hypochondriacus Dunaliella -- Amaranthus antennae size, reduced Dl protein synthesis and through decreased -- chapter 55 Acclimation to Changing Light Regime -- chapter f. The pattern reversed between irrdiances 475 to 810 jimol m s\ -- chapter Arabidopsis -- plants which have previously adapted to mechanism exists to communicate EEE so that a defense against stress changes in the PS II, H -- chapter 6 Transgenic and Biotechnological Approaches -- chapter Chlamydomonas reinhardtii Arabidopsis -- photosystem II. Their studies clearly dmonstrated that the mutants, Dl -- chapter Flachmann (1997) studied the PS II antennae composition under varying light conditions in tobacc o plants transformed with antisense echnique. An increase of P S II antenna size was observed under low irradiance and also higher LHC II content. The results also suggested that LHC II biogenesis is perhaps not controlled by transcription. The foregone account of different studies using transgenics have inmmensely helped by adding new dimension in our understanding of the structure and function of the photosystem core complexes and of the antennae systems related to both PS II and PS I.A fairly larg e number of studies have also been directed using transgenic technology to understand the process of photoinhibition. Tyystjarvi et al., (1999b) have made a study of photoinhibition of PS II in tobacco an d poplar plants. The tobacco cultivars were expressed with bacterial gov gene in the cytosol and Fe SOD gene from Arabidopsis thaliana rather in the chloroplast. The transformations were affected as an overexpression of glutathione reductase in tobacco and superoxide dismutase in poplar. This transformation resulted in the activities of glutathione reductase in tobacco leaves and superoxide dismutase in poplars were five to eight times higher than in the untransformed plants. The experiments of the authors (Tyystjarvi et al., (1999b) with the transformed plants have led to some important clues regarding the identity of Active Oxygen Species and the mechanisms. There was a lack of protection by overproduction of SOD in the stroma, suggesting that superoxide is not accessible to dismutation by the stromal enzymes. Protection by glutathione reductase suggested that a soluble reductant has a limited chance to trap the species before it reacts with PS II RC. It was concluded (Tyystjarvi et al., 1999b) that much further work is required to understand the molecular mechanism of loss of PS II activity. H.Y. Yamamoto and his scholars have made several studies manipulating the levels of the enzymes of the xanthophyll cycle through transgenic techniques. Verhoeven et al., (2001) have investigated the effect of suppression of Z in tobacco plants with an antisense construct of VDE in growth chambers. Under short-term (2 or 3h) high light treatment, antisense plants had a greater reduction in Fv/Fm ratio relative to wild type, which implied a greater susceptibity to photoinhibition. In the long-term highlight stress experiment, the antisense plants had significant reduction in Fv/Fm. The authors concluded that XC-dependent energy dissipiation is critical for photoprotection in tobacco under excess light in the long term. -- chapter Arabidopsis Chlamydomonas Arabidopsis Chlamydomonas Synechocystis Arabidopsis -- mutants are qualitatively similar to results obtained with equivalent mutants of Chlamydomonas. Structural and photophysical similarity has been noticed between Z and lutein. It is, therefore, possible that some lutein molecules bound to PS II protein perhaps PsbS may play a direct role in the ApH and xanthophyll dependant NPQ. The roles of xanthophylls in photoprotection has been -- chapter 7 Concluding Remarks -- chapter 8 References -- chapter unedo -- Farhoosh R, Frank Biophys. Acta. 1102: 107-109. Demmig-Adams B, 1990, Carotenoids and photoprotection in plants: a 1-24. -- chapter Quercus ilex Arabidopsis thaliana -- Genty B, Harbinson J, 1996, Regulation of light utilization for photosynthetic electron transport. In: NR Baker, (ed.) Photosynthesis pp. 69-99. -- chapter Arabidopsis Chenopodium album -- during excess light stress. Plant Cell 9: 627-640. Karpinski S, Reynolds H, Karpinska excitation energy in Arabidopsis. Science 284: 654-657. Karpinski S, Wingsle G, Karpinska B, Hallgren -- chapter ApH -dependent quenching. Biochim. Biophys. Acta 723: Rhodopseudomonas viridis -- 169-175. Krause GH, Wiese E, 1991, Chlorophyll fluorescence and photosynthesis: Krauss N, Sehabert W-D, Klukas O, Fromme P, Witt HT, Senger W, 1996, Photosystem I at 4 Â resolution represents the first structural model -- chapter Syneehocystis Malva negleeta. Dunaliella salina: -- important residues in the Dl protein of the photosystem II reaction center. Plant Cell Physiol. 43: 540-548. Yamashita N, Ishida A, Kushima H, Tanaka N, 2000, Acclimation to sudden increase in light favouring an invasive over native/trees in subtropical islands, Japan. Occologia 125: 412-419 |
| Summary |
The aim of this monograph is to highlight various mechanisms followed by plants to overcome the high light stress and photoinhibition, and also the plant responses to low light levels. Emphasis has been on the regulation of light harvesting process, the avoidance phenomena at leaf and chloroplast levels and the strategy followed by certa in solar tracking plants in maximizing the light interception without photoinhibitory damage, leading to improvement of diurnal photosynthetic rate. Plant adjustment to light variations over a long term, through the acclimation process brought about by changes in gene function and specific reconstruction of chloroplast has also been discussed. Although the emphasis has been on higher plant systems, green algae and cyanobacterial examples are used wherever appropriate. This book will be a useful reference to advanced postgraduate students, research scientists and teachers interested in the area of photosynthesis research |
| Bibliography |
Includes bibliographical references and index |
| Subject |
Photosynthesis.
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Photosynthesis
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| Form |
Electronic book
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| ISBN |
9781482294446 |
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1482294443 |
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