U.S.-Chile Cooperative Research: Effects of UV-B Radiation on Photosynthesis in Bean and Maize

9724829 Ku这一美洲计划奖将资助华盛顿州立大学的Maurice Ku博士和Gerald B.Edwards博士以及智利大学的Manuel Pinto和Cldio Pastenes博士之间关于植物对UV-B辐射的反应的合作研究项目。这项研究的主要目的是确定补充UV-B辐射诱导的豆类(C3种)和玉米(C4种)光合作用的光化学、生化和生理过程中的特定变化，并评价这些变化与光合作用速率损失/变化的关系。其目的是确定光化学效率和光合酶的改变是否与UV-B处理引起的光合作用能力的变化有关。该假说认为，UV-B辐射引起的菜豆光合作用能力的下降可能与关键光合酶的变化和/或光化学效率的变化有关。在这项研究中，将使用对UV-B耐受性不同的代表性菜豆品种。在过去的三十年里，涉及UV-B辐射对植物系统影响的研究有了显著的增加。根据这些研究，据估计，大约一半的植物物种(特别是草本植物)受到这种增加的辐射的负面影响。然而，由于已知一些物种很好地适应高UV-B辐射环境，比较UV-B处理过程中酶活性与蛋白质含量的变化将使研究人员能够评估蛋白质数量或激活状态的变化是否导致光合作用能力的丧失/变化。植物与环境之间的相互作用是复杂的，但对我们理解植物生产力很重要。平流层臭氧主要吸收UV-B辐射，它的减少引起了人们对地球表面UV-B辐射增加的潜在影响的关注。***

9724829 Ku This Americas Program award will fund a collaborative research project on plant responses to UV-B radiation, between Drs. Maurice Ku and Gerald B. Edwards, Washington State University , and Drs. Manuel Pinto and Claudio Pastenes, University of Chile. The major objectives of the proposed study are to identify specific alterations in photochemical, biochemical and physiological processes of photosynthesis induced by supplementary UV-B radiation in bean (C3 species) and maize (C4 species), and to evaluate the relationship between these alterations and the loss/change in photosynthetic rate. The purpose is to determine if modifications in photochemical efficiency and photosynthetic enzymes correlate with changes in photosynthetic capacity by UV-B treatment. The hypothesis is that the decrease in photosynthetic capacity in bean caused by UV-B radiation would be related to changes in key photosynthetic enzymes and/or changes in photochemical efficiency. For this study, representative bean cultivars with contrasting tolerance to UV-B will be used. Over the past three decades, there has been a significant increase in research involving the effects of UV-B radiation on plant systems. Based on those studies, it is estimated that about one half of all plants species, (especially herbaceous species) are negatively affected by that increased radiation. However, because some species are known to be well adapted to high UV-B radiation environments, a comparison of changes in enzyme activity versus protein content during UV-B treatment will allow the researchers to assess if the changes in protein amount or activation state is responsible for the loss/change of photosynthetic capacity. Interactions between plants and their environment are complex, but important to our understanding of plant productivity. Reduction of stratospheric ozone, which primarily absorbs UV-B radiation, has raised concerns about the potential implications of rising UV-B radia tion at the Earth's surface. ***