Tansley Review No. 111: Possible roles of zinc in protecting plant cells from damage by reactive oxygen species.

摘要: Summary 185 I. INTRODUCTION 186 II. EFFECT OF ZINC ON PRODUCTION REACTIVE OXYGEN SPECIES 186 1. Superoxide-generating NADPH oxidase 186 2. Zinc deficiency potentiates iron-mediated free radical production 189 (a) Iron accumulation in zinc-deficient plants 189 (b) Iron-induced of radicals 189 3. deficiency-enhanced photooxidation 191 (a) Decrease photosynthesis 191 (b) Light-induced leaf chlorosis 192 (c) indole-3-acetic acid 192 III. MEMBRANE DAMAGE BY 193 1. Impairments membrane structure 193 2. Phospholipids and –SH groups 195 3. Alterations ion absorption 195 (a) Membrane-bound ATPases 195 (b) Nutrient uptake 197 (c) Changes activity channels 197 IV. DETOXIFICATION 198 1. Superoxide dismutases 198 2. H2O2-scavenging enzymes 198 V. INVOLVEMENT IN PLANT STRESS TOLERANCE 199 VI. CONCLUSIONS 199 Acknowledgements 200 References 200 Zinc is one the most widespread micronutrient deficiencies causes severe reductions crop production. There are a number physiological impairments Zn-deficient cells causing inhibition growth, differentiation development plants. Increasing evidence indicates that oxidative damage to critical cell compounds resulting from attack by reactive O2 species (ROS) basis disturbances plant growth caused Zn deficiency. interferes with membrane-bound producing ROS. In iron concentration increases, which radicals. The nutritional status influences photooxidative chloroplasts, catalysed Zinc-deficient leaves highly light-sensitive, rapidly becoming chlorotic necrotic when exposed high light intensity. plays roles defence system against ROS, thus represents an excellent protective agent oxidation several vital components such as lipids proteins, chlorophyll, SH-containing DNA. cysteine, histidine glutamate or aspartate residues represent Zn- binding sites enzymes, DNA-binding proteins (Zn-finger proteins) proteins. addition, animal studies have shown involved apoptosis (programmed death) preceded DNA through reactions