Elevated CO2 induces physiological, biochemical and structural changes in leaves of Arabidopsis thaliana.
Leaves of Arabidopsis thaliana grown under elevated or ambient CO2 (700 or 370 micromol mol(-1), respectively) were examined for physiological, biochemical and structural changes. Stomatal characters, carbohydrate and mineral nutrient concentrations, leaf ultrastructure and plant hormone content were investigated using atomic absorption spectrophotometry, transmission electron microscopy and enzyme-linked immunosorbent assay (ELISA). Elevated CO2 reduced the stomatal density and stomatal index of leaves, and also reduced stomatal conductance and transpiration rate. Elevated CO2 increased chloroplast number, width and profile area, and starch grain size and number, but reduced the number of grana thylakoid membranes. Under elevated CO2, the concentrations of carbohydrates and plant hormones, with the exception of abscisic acid, increased whereas mineral nutrient concentrations declined. These results suggest that the changes in chloroplast ultrastructure may primarily be a consequence of increased starch accumulation. Accelerated A. thaliana growth and development in elevated CO2 could in part be attributed to increased foliar concentrations of plant hormones. The reductions in mineral nutrient concentrations may be a result of dilution by increased concentrations of carbohydrates and also of decreases in stomatal conductance and transpiration rate.
Teng
Nianjun
N
Key laboratory of Photosynthesis and Environmental Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
Wang
Jian
J
Chen
Tong
T
Wu
Xiaoqin
X
Wang
Yuhua
Y
Lin
Jinxing
J
D017360:Arabidopsis / Q000033:anatomy & histology / Q000187:drug effects* / Q000502:physiology; D002241:Carbohydrates / Q000032:analysis; D002245:Carbon Dioxide / Q000494:pharmacology*; D002736:Chloroplasts / Q000648:ultrastructure; D004305:Dose-Response Relationship, Drug; D018515:Plant Leaves / Q000033:anatomy & histology / Q000737:chemistry / Q000187:drug effects* / Q000502:physiology; D018526:Plant Transpiration / Q000187:drug effects
D002241:Carbohydrates; D002245:Carbon Dioxide