Leaf Biochemical and Physiological Responses to Elevated Atmospheric Ozone Concentration in Eight Modern Rice Cultivars

作者：Longxin He, Mingxu Bao, Yi Li, Yansen Xu, Zaisheng Shao, Yanze Ma, Kun Zhang, Bo Shang, Zhaozhong Feng · 发表于：Ecosystem Health and Sustainability · 年份：2024 · DOI：10.34133/ehs.0269 · 被引用次数：4 · 研究领域：Plant responses to elevated CO2、Atmospheric chemistry and aerosols

This study investigated the effects of elevated O 3 level on photosynthetic traits and antioxidant systems of various rice genotypes under fully open-air conditions. Eight modern rice cultivars ( Oryza sativa L.), including 4 hybrids and 4 inbreds, were exposed to 2 O 3 treatments: the ambient atmosphere (A-O 3 ) and the 1.5 times ambient O 3 concentration (E-O 3 ) throughout the reproductive period. The measurements of gas exchange, chlorophyll a fluorescence, photosynthetic pigments, lipid oxidation, antioxidant content, and antioxidant enzyme activity were conducted on the flag leaf during the early and late grain-filling periods. The results indicated that E-O 3 had differential effects on the photosynthesis and antioxidant indicators of rice genotypes. In the hybrid rice, the reduction in the light-saturated photosynthetic rate ( A sat ) was primarily due to the nonstomatal factors, such as the changes in antioxidants, particularly ascorbate and carotenoids. In contrast, the reduction in A sat levels in inbred rice was mainly due to the stomatal factors. Additionally, the hybrid rice was more sensitive to O 3 than the inbred rice, with the sensitivity determinants varying between types. The sensitivity of hybrid rice to O 3 was influenced by the magnitude of its antioxidant capacity, whereas the inbred rice sensitivity was determined by the stomatal conductance ( g s ) and the antioxidant enzyme activity. The rice cultivars with higher antioxidant enzyme activities could...