|
KMID : 1024519920010010051
|
|
Journal of the Environmental Sciences
1992 Volume.1 No. 1 p.51 ~ p.59
|
|
|
Effect of CO₂ Enrichment on Photosynthetic Rates, Enzyme Activity rind End Products of toro Poplar Clones, 1-214 (Populus euramericana) and Peace (P. Koreana x P. trichocarpa)
|
|
Park Shin-Young
Furukawa Akio
|
|
|
Abstract
|
|
|
|
Two comparative poplar clones (I-214: Populus euramerinm, Peace: P koreana x p. trihocarpa) were exposed to two concentrations (350 or 2, 000 ) for 21 days. When both poplar clones were compared at growth conditions, the net photosynthetic rate () in -enriched () plants become about 50-60% higher than that of 350 Plants on 7 days treatment. But the enhancement of PN by high was not maintained throughout all the experimental period. At 21 days, there was no difference of photosynthetic rates between and plants. In contrast with photosynthesis, the response of leaf conductance to the elevated concentration was very different between I-214 and Peace. During all experimental period, leaf conductance () of plants is 50% lower than that of the plants for I-214, while there is no difference of gs between the plants of and for Peace. The results of gs in Peace indicate that decreased photosynthetic rate after 21 days in Plants for two poplar clones is possibly due to non-stomatal factors. To investigate the non-stomatal factors, starch accumulation and ribulose-1, 6-bisphosphate carboxylase (RuBPCase) were measured. We found significant accumulation of starch in two poplar clones exposed to high , especially starch of I-214 in become 3.5 times higher than in plants at 21 days. This suggests that high proportion of photosynthates was directed into starch. After 21 days, the activity of ribulose-1, 6-bisphosphate carboxylase of plants become decreased in 40-50% compared with that of the plants. Two poplar clones show the same trend to RuBPCase declines under high concentration, although the decline is more significant for I-214. The results reported here suggest that starch accumulation and decreased RuBPCase activity in plants can be partly ascribed to the loss of photosynthetic efficiency of high -grown poplar plants.
|
|
|
KEYWORD
|
|
|
Photosynthetic rate, Leaf Conductance, Starch, High CO₂
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
|
|