臭氧胁迫对植物主要生理功能的影响

Abstract

Nowadays,with the increase of ozone precursor caused by photochemical reactions,the extent of global plants suffering from ozone stress in the troposphere is getting more and more serious. Ozone pollution has been considered to be the primary cause of forest decline and tree dieback in Eastern and Western Europe and throughout the United States. Ozone stress could have strong impacts on the utilization of light and the production of photosynthesis products in plants,and lead to the decline of photosynthetic rate through stomatal limitation and non-stomatal limitation. The effects of ozone on plants are closely related to the accumulation of metabolic substance in plants. Various defensive protection mechanisms are initiated by ozone stress,such as antioxidant system and membrane system. Ozone stress has changed the absorption of carbon and mineral nutrients in plants and caused their redistribution. And it could also induce deep changes in gene expression. In order to adapt to the environment with ozone stress,plants adjust their physiological and biochemical mechanism to ensure their vital movement. For example,the content of permeable mass would be regulated by cell to maintain osmotic potential balance,meanwhile the metabolic pathway would be changed to keep energy reserves and reduce metabolic rate in plants. And all kinds of antioxidant enzymes' activity in the cell would increase to clear up free radicals and mitigate or even avoid cell damages. It' s clear that the ecological environment has important effects on biological evolution. And it's confirmed by the plants' physiological effects from ozone stress,which is also another kind of evidence of biological evolutionism. In this paper,the impacts that ozone does to plants' photosynthetic physiology,respiratory metabolism,antioxidant system,membrane system,nutrients absorption and allocation,and molecular physiology were summarized to get a more comprehensive understanding of the physiological and biochemical mechanism of plants adapting to ozone stress. Hotspots for future ozone researches should be focused on the enhancement of effects of ozone stress on plant physiology in individual and community level,the gene regulation and related mechanism of signal transmission network system of plants under ozone stress,plants breeding to adapt to the environment with ozone stress by methods such as molecular marker,gene mapping,genomics approach and transgenic technology,research condition that should be close to natural environment as much as possible,the effects of ozone stress on major physiological functions of subtropical and tropical forests,and the models to assess the impacts of ozone on plants.