Boron deficiency decreases growth and photosynthesis, and increases starch and hexoses in leaves of citrus seedlings
| Autor: | Brandon R. Smith, Lin-Tong Yang, Li-Song Chen, Cheng-Yu Xie, Shuang Han, Huan-Xin Jiang |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
Chlorophyll
Citrus Stomatal conductance Antioxidant Physiology medicine.medical_treatment Photosynthetic Reaction Center Complex Proteins Glutathione reductase Plant Science Reductase Plant Roots Superoxide dismutase chemistry.chemical_compound medicine Food science Photosynthesis Boron Hexoses Plant Proteins Plant Stems biology Chemistry RuBisCO Plant Transpiration Starch Glutathione APX Carotenoids Biochemistry biology.protein Agronomy and Crop Science |
| Zdroj: | Journal of Plant Physiology. 165:1331-1341 |
| ISSN: | 0176-1617 |
| DOI: | 10.1016/j.jplph.2007.11.002 |
| Popis: | Seedlings of sweet orange (Citrus sinensis) were fertilized for 14 weeks with boron (B)-free or B-sufficient (2.5 or 10 microM H(3)BO(3)) nutrient solution every other day. Boron deficiency resulted in an overall inhibition of plant growth, with a reduction in root, stem and leaf dry weight (DW). Boron-starved leaves showed decreased CO(2) assimilation and stomatal conductance, but increased intercellular CO(2) concentrations. Activities of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), NADP-glyceraldehyde-3-phosphate dehydrogenase (NADP-GAPDH) and stromal fructose-1,6-bisphosphatase (FBPase) were lower in B-deficient leaves than in controls. Contents of glucose, fructose and starch were increased in B-deficient leaves while sucrose was decreased. Boron-deficient leaves displayed higher or similar superoxide dismutase (SOD), ascorbate peroxidase (APX), monodehydroascorbate reductase (MDAR) and glutathione reductase (GR) activities, while dehydroascorbate reductase (DHAR) and catalase (CAT) activities were lower. Expressed on a leaf area or protein basis, B-deficient leaves showed a higher ascorbate (AsA) concentration, but a similar AsA concentration on a DW basis. For reduced glutathione (GSH), we found a similar GSH concentration on a leaf area or protein basis and an even lower content on a DW basis. Superoxide anion (O(2)(-)) generation, malondialdehyde (MDA) concentration and electrolyte leakage were higher in B-deficient than in control leaves. In conclusion, CO(2) assimilation may be feedback-regulated by the excessive accumulation of starch and hexoses in B-deficient leaves via direct interference with chloroplast function and/or indirect repression of photosynthetic enzymes. Although B-deficient leaves remain high in activity of antioxidant enzymes, their antioxidant system as a whole does not provide sufficient protection from oxidative damage. |
| Databáze: | OpenAIRE |
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