Effects of the interaction between ozone and carbon dioxide on gas exchange, ascorbic acid content, and visible leaf symptoms in rice leaves
Year: 2008
Type: article
Abstract: Tropospheric ozone (O3) decreases photosynthesis, growth, and yield of crop plants, while elevated carbon dioxide (CO2) has the opposite effect. The net photosynthetic rate (P N), dark respiration rate (R D), and ascorbic acid content of rice leaves were examined under combinations of O3 (0, 0.1, or 0.3 cm3 m-3, expressed as O0, O0.1, O0.3, respectively) and CO2 (400 or 800 cm3 m-3, expressed as C400 or C800, respectively). The P N declined immediately after O3 fumigation, and was larger under O0.3 than under O0.1. When C800 was combined with the O3, P N was unaffected by O0.1 and there was an approximately 20 % decrease when the rice leaves were exposed to O0.3 for 3 h. The depression of stomatal conductance (g s) observed under O0.1 was accelerated by C800, and that under O0.3 did not change because the decline under O0.3 was too large. Excluding the stomatal effect, the mesophyll P N was suppressed only by O0.3, but was substantially ameliorated when C800 was combined. Ozone fumigation boosted the R D value, whereas C800 suppressed it. An appreciable reduction of ascorbic acid occurred when the leaves were fumigated with O0.3, but the reduction was partially ameliorated by C800. The degree of visible leaf symptoms coincided with the effect of the interaction between O3 and CO2 on P N. The amelioration of O3 injury by elevated CO2 was largely attributed to the restriction of O3 intake by the leaves with stomatal closure, and partly to the maintenance of the scavenge system for reactive oxygen species that entered the leaf mesophyll, as well as the promotion of the P N.
Source: Photosynthetica
Authors: K. Imai, K. Kobori
Institution: Meiji University
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDGs: Zero hunger, Climate action
Open Access status: bronze
OpenAlex ID: W2127331229