de Luitjen Kok

Plant Responses to Air Pollution and Global Change

Preface by Kenji Omasa, Isamu Nouchi and Luit J. De Kok Contributors Plant Responses to Air Pollution: Metabolism of atmospheric sulfur gases in onion.- Impact of atmospheric NH3 deposition on plant growth and functioning - a case study with Brassica oleracea L..- How sensitive are forest trees to ozone? - New research on an old issue.- Northern conditions enhance the susceptibility of birch (Betula pendula Roth) to oxidative stress caused by ozone.- Physiological responses of trees to air pollutants at high elevation sites.- Complex assessment of forest condition under air pollution impacts.- Evaluation of the ozone-related risk for Austrian forests.- Causes of differences in response of plant species to nitrogen supply and the ecological consequences.- Plant Responses to Climate Change: Long-term effects of elevated CO2 on sour orange trees.- Plant responses to climate change: impacts and adaptation.- Effects of elevated carbon dioxide concentration on wood structure and formation in trees.- Plant Responses to Combination of Air Pollution and Climate Change: Carbon dioxide and ozone affect needle nitrogen and abscission in Pinus ponderosa.- Effects of air pollution and climate change on forests of the Tatra Mountains, Central Europe.- Genetics and Molecular Biology for Functioning Improvement: MAPK signalling and plant cell survival in response to oxidative environmental stress.- Expression of cyanobacterial ictB in higher plants enhanced photosynthesis and growth.- Improvement of photosynthesis in higher plants.- Modification of CO2 fixation of photosynthetic prokaryote.- Specificity of diatom Rubisco.- Regulation of CO2 fixation in non-sulfur purple photosynthetic bacteria.- Experimental Ecosystem and Climate Change Research: Experimental ecosystem and climate change research in controlled environments:lessons from the Biosphere 2 Laboratory 1996-2003.- Importance of air movementfor promoting gas and heat exchanges between plants and atmosphere under controlled environments.- Pros and cons of CO2 springs as experimental sites.- Global Carbon Cycles in Ecosystem and Assessment of Climate Change Impacts: Carbon dynamics in response to climate and disturbance: Recent progress from multi-scale measurements and modeling in AmeriFlux.- Synthetic analysis of the CO2 fluxes at various forests in East Asia 3-D remote sensing of woody canopy height and carbon stocks by helicopter-borne scanning lidar.- Assessments of climate change impacts on the terrestrial ecosystem in Japan using the Bio-Geographical and GeoChemical (BGGC) Model.- Air Pollution and Global Change in Asia: Establishing critical levels of air pollutants for protecting East Asian vegetation - A challenge.- Major activities of acid deposition monitoring network in East Asia (EANET) and related studies.- Land degradation and blown-sand disaster in China.- Impact of meteorological fields and surface conditions on Asian dust.- A case study on combating desertification at a small watershed in the hills-gully area of loess plateau, China.- A recipe for sustainable agriculture in drylands.- Index

Significance of Glutathione to Plant Adaptation to the Environment

Preface. 1. Glutathione - An ancient metabolite with modern tasks H. Rennenberg. 2. Chemistry of glutathione W. Wonisch, R.-J. Schaur. 3. The molecular biology and metabolism of glutathione C.H. Foyer, G. Noctor. 4. The role of glutathione in the uptake and metabolism of sulfur and selenium J.W. Anderson, P.J. McMahon. 5. The role of glutathione in plant response and adaptation to natural stress M. Tausz. 6. The role of glutathione in plant reaction and adaptation to excess metals W.E. Rauser. 7. The role of glutathione and glutathione S-transferases in plant reaction and adaptation to xenobiotics P. Schroder. 8. The role of glutathione in plant reaction and adaptation to air pollutants L.J. De Kok, M. Tausz. 9. The role of glutathione and glutathione-related enzymes in plant-pathogen interactions G. Gullner, T. Komives. 10. Aspects of glutathione in the interaction between plants and animals E. Schnug, C. Sator. Index.

Fatty acid composition and chlorophyll content of epiphytic lichens and a possible relation to their sensitivity to air pollution.

Fatty acid composition and chlorophyll content of thirteen epiphytic lichen species were determined and related to the air pollution sensivity of the lichens based upon field observations. A direct relation between the chlorophyll content and, to a lesser extent, the degree of unsaturation of the fatty acids of the lichen species and the sensitivity to air pollution was demonstrated. It is suggested that the sensitivity of lichens to air pollution is related to the degree of dependency of the mycobiont on the phycobiont as far as metabolic energy is concerned; in such a way that the stronger this dependency is, the more sensitive the lichen will be to air pollution.

Plant functioning in a changing global environment.

This supplement contains a selection of papers presented at the Air Pollution and Global Change (APGC) Symposium entitled ‘Plant functioning in a Changing Global Environment,’ held in December 2008 at the Creswick Campus of the Melbourne School of Land and Environment, University of Melbourne, Australia. The previous symposia in this series were held in Oxford, UK (1982), Munich, Germany (1987), Blacksburg, USA (1992), Egmond aan Zee, The Netherlands (1997), Pulawy, Poland (2001) and Tsukuba, Japan (2004), and the 8th APGC Symposium, entitled ‘Plant Functioning in a Changing Global and Polluted Environment,’ will be held in Groningen, The Netherlands in June 2011. Over the lifetime of the symposium series, as is also obvious from the content of the proceedings volumes issued, research has gradually moved from the responses of plants to air pollution, viz. SO2 and NOx (Koziol & Whatley 1984), SO2, NOx and O3 (Schulte-Hostede et al. 1988), air pollution and elevated CO2 (Alscher & Wellburn 1994), to air pollution and global change factors in general (De Kok & Stulen 1998; De Kok et al. 2002; Omasa et al. 2005a,b). In times when climate change is (back) on the public agenda, driven by the conclusions of the Intergovernmental Panel on Climate Change (Pachauri & Reisinger 2007), this symposium series provides a timely representation of the scientific focus, dependent not only on temporary ‘hot topics’, but also on geographical origin of the research. Evidently, the 2008 APGC Symposium clearly demonstrated that there is a geographical diversification of research interests in the area of plant responses to global change. Whilst especially Australian, but also some European researchers, appear to concentrate on CO2 and climate change-related changes in ‘natural’, abiotic stress levels, air pollution (particularly ozone – O3) is an ever growing concern in many parts of the Northern Hemisphere, most notably in Japan and neighbouring, currently industrialising countries of the region. In the current supplement, the importance of the direct exchange of gases between plants and the atmosphere is reviewed by Cieslik et al. (2009). This paper underlines the importance of pollutants such as O3, which originates in the same fossil fuel burning processes that cause increasing CO2 levels. The authors analyse environmental feedbacks on gas exchange processes, and also note the potential of plant feedbacks to the atmosphere, for example through the emission of volatile organic compounds. Dizengremel et al. (2009) analysed the metabolic detoxification pathways that protect plants against O3. They emphasise that the electron flux through anti-oxidative regeneration cycles ultimately limits plant defence capacity, and the authors claim that determination of available reducing power will greatly improve assessment of O3 risk to vegetation. Sawada & Kohno (2009) observed remarkable variability among rice cultivars in their sensitivity towards O3. Their study revealed that there is no clear correlation between visible symptom assessment and yield, thus all but eliminating visual assessment of foliar symptoms as an easy screening option for resistant cultivars. Singh et al. (2009) investigated the O3 tolerance of tropical soybean varieties and observed that the adverse effects of O3 on assimilation are apparently not (exclusively) related to stomatal closure, but also to effects on the photosynthetic apparatus. In general, the investigated tropical varieties did not show tolerances that were very different from previously investigated cultivars from temperate climate areas. Plants can be a significant source of greenhouse gases. Emission of methane (CH4, a strong greenhouse gas) from plant material was investigated by Bruhn et al. (2009). They show a strong stimulation of CH4 with temperature, but also with increasing UV-B levels, which could potentially lead to a feed-forward response under current climate change scenarios – climate changerelated increases in temperatures lead to increased release of this strong greenhouse gas, thus reinforcing a vicious circle. The direct effect of elevated CO2 on plants remains an ongoing concern around the world. In a FACE (Free Air Carbon dioxide Enrichment) study in Germany, Högy et al. (2009) showed that growth under elevated CO2 will alter a number of grain traits that determine nutritional value and market quality of wheat. Gleadow et al. (2009) reported that tuber yield of cassava (Manihot esculenta) decreases sharply, and concentrations of toxic cyanogenic glucosides in the leaves increase under exposure to elevated CO2. Given that cassava tubers are a staple food in many of the poorest regions of our planet, and that leaves are often eaten as a protein supplement, this is an alarming result. Burkart et al. (2009) studied canopy gas exchange of sugar beet (Beta vulgaris) in a FACE system and found that N limitation can impose restrictions on canopy gas exchange (especially on maximum light use efficiency of the canopy) early in the growing season, but that a similar decline later in the season is independent of N supply. The authors conclude that photosynthetic acclimation to high CO2 related to sink limitations may appear towards the end of the growing season, underlining the complexity of whole plant responses to high CO2. Plant Biology ISSN 1435-8603

Copper toxicity in Chinese cabbage is not influenced by plant sulphur status, but affects sulphur metabolism-related gene expression and the suggested regulatory metabolites

The toxicity of high copper (Cu) concentrations in the root environment of Chinese cabbage (Brassica pekinensis) was little influenced by the sulphur nutritional status of the plant. However, Cu toxicity removed the correlation between sulphur metabolism-related gene expression and the suggested regulatory metabolites. At high tissue Cu levels, there was no relation between sulphur metabolite levels viz. total sulphur, sulphate and water-soluble non-protein thiols, and the expression and activity of sulphate transporters and expression of APS reductase under sulphate-sufficient or-deprived conditions, in the presence or absence of H2 S. This indicated that the regulatory signal transduction pathway of sulphate transporters was overruled or by-passed upon exposure to elevated Cu concentrations.

Temperature determines size and direction of effects of elevated CO2 and nitrogen form on yield quantity and quality of Chinese cabbage.

Rising atmospheric CO2 concentrations (e[CO2 ]) are presumed to have a significant impact on plant growth and yield and also on mineral nutrient composition, and therefore, on nutritional quality of crops and vegetables. To assess the relevance of these effects in future agroecosystems it is important to understand how e[CO2 ] interacts with other environmental factors. In the present study, we examined the interactive effects of e[CO2 ] with temperature and the form in which nitrogen is supplied (nitrate or ammonium nitrate) on growth, amino acid content and mineral nutrient composition of Chinese cabbage (Brassica pekinensis Rupr.), a crop characterised by its high nutritional value and increasing relevance for human nutrition in many developing countries. Higher temperature, ammonium nitrate and e[CO2 ] had a positive impact on net photosynthesis and growth. A stimulating effect of e[CO2 ] on growth was only observed if the temperature was high (21/18 °C, day/night), and an interaction of e[CO2 ] with N form was only observed if the temperature was ambient (15/12 °C, day/night). Mineral nutrient composition was affected in a complex manner by all three factors and their interaction. These results demonstrate how much the effect of e[CO2 ] on mineral quality of crops depends on other environmental factors. Changes in temperature, adapting N fertilisation and the oxidation state of N have the potential to counteract the mineral depletion caused by e[CO2 ].