The content of soluble protein in plant leaves with high CO2 concentration decreased. Similar results were obtained with FACE under growth conditions: at the heading and filling stages, the soluble protein content of wheat leaves measured by the CO2 measurement instrument decreased significantly, about 20% to 20% lower than the FACE circle. . The relationship between light adaptation and stomatal conductance may vary depending on the type of plant. Under the condition of FACE, the net photosynthetic rate of C4 plants grown in Pteris vittata decreased obviously, and the stomatal conductance and intercellular CO2 concentration were also significantly reduced by CO2 measurement instrument, which indicated that the light adaptability of C. communis leaves should be at least partially reduced by the stomatal conductance. And what happened.
When the same CO2 concentration was measured with the CO2 meter, the Pn of wheat leaves within the FACE circle was significantly lower than that of the control at the three stages, and the ratios were 91%, 86%, and 87%, respectively, and the Gs was also significantly lower than the control. The ratios were 83%, 82%, and 76%, respectively. However, at the heading and filling stages, there was no significant difference between the Ci of the wheat leaves within the FACE circle and the control. At the same time, the carboxylation efficiency of wheat leaves within the FACE circle was significantly reduced, which was reduced by 9% and 19% at the heading and filling stages, respectively, compared to the control. The above results indicate that the photosynthesis of wheat leaves under long-term growth conditions in FACE occurred.
The reason for the light adaptability of plants growing under high CO2 concentration was thought to be due to the reduction of leaf stomatal conductance. However, our experimental results do not support this view, although the stomatal conductance of wheat leaves in the FACE circle is significantly lower than that in the FACE circle. Control, but its intercellular CO2 concentration is not always significantly lower than the control, at least at the heading and filling stages. The significant decrease in the carboxylation efficiency of wheat leaves within the FACE circle indicates that the light adaptation of wheat leaves may be caused by a decrease in the content of key enzymes involved in photosynthesis in mesophyll cells.
When the growth of the root system is not limited, the carbon dioxide measurement instrument detects the increase in the concentration of open air CO2 or the outburst causes the winter wheat light to adapt to the phenomenon. Therefore, in the case of winter wheat light adaptation, it cannot be explained using root growth restrictions or restrictions on photosynthetic product pools. However, the phenomenon of photosynthesis should not be attributed to insufficient supply of nitrogen, because the adequate light phenomenon of wheat is also observed in the case of nitrogen.
When the same CO2 concentration was measured with the CO2 meter, the Pn of wheat leaves within the FACE circle was significantly lower than that of the control at the three stages, and the ratios were 91%, 86%, and 87%, respectively, and the Gs was also significantly lower than the control. The ratios were 83%, 82%, and 76%, respectively. However, at the heading and filling stages, there was no significant difference between the Ci of the wheat leaves within the FACE circle and the control. At the same time, the carboxylation efficiency of wheat leaves within the FACE circle was significantly reduced, which was reduced by 9% and 19% at the heading and filling stages, respectively, compared to the control. The above results indicate that the photosynthesis of wheat leaves under long-term growth conditions in FACE occurred.
The reason for the light adaptability of plants growing under high CO2 concentration was thought to be due to the reduction of leaf stomatal conductance. However, our experimental results do not support this view, although the stomatal conductance of wheat leaves in the FACE circle is significantly lower than that in the FACE circle. Control, but its intercellular CO2 concentration is not always significantly lower than the control, at least at the heading and filling stages. The significant decrease in the carboxylation efficiency of wheat leaves within the FACE circle indicates that the light adaptation of wheat leaves may be caused by a decrease in the content of key enzymes involved in photosynthesis in mesophyll cells.
When the growth of the root system is not limited, the carbon dioxide measurement instrument detects the increase in the concentration of open air CO2 or the outburst causes the winter wheat light to adapt to the phenomenon. Therefore, in the case of winter wheat light adaptation, it cannot be explained using root growth restrictions or restrictions on photosynthetic product pools. However, the phenomenon of photosynthesis should not be attributed to insufficient supply of nitrogen, because the adequate light phenomenon of wheat is also observed in the case of nitrogen.