Wang Junli, Zeng Qing, Zhu Jianguo, Chen Chen, Liu Gang, Tang Haoye
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Sciences, Chinese Academy of Sciences, Nanjing 210008, PR China; Graduate University of Chinese Academy of Sciences, Beijing 100049, PR China.
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Sciences, Chinese Academy of Sciences, Nanjing 210008, PR China.
Plant Physiol Biochem. 2014 Sep;82:183-93. doi: 10.1016/j.plaphy.2014.06.004. Epub 2014 Jun 18.
The effects of elevated ozone concentrations [O3] on two different ozone-sensitive wheat (Triticum aestivum L.) cultivars [Yangmai16 (Y16) and Yannong19 (Y19)] were investigated to determine the different apoplastic antioxidant mechanisms under O3-FACE (free-air controlled enrichment) condition. The results indicated that elevated [O3] (1.5 × ambient [O3]) induced increases in the production of superoxide anion (O2(-)), hydroxyl radical (HO), hydrogen peroxide (H2O2) and lipid peroxidation, and these results were more pronounced in the apoplasts of Y19 than in those of Y16. Apoplastic antioxidant enzymes were developmentally regulated and the effect of elevated [O3] depended on the developmental stage of wheat for both cultivars. In cultivar Y19, continuous O3 stress induced a decrease in the activity of apoplastic superoxide dismutase (SOD; EC 1.15.1.1), peroxidase (POD; EC 1.11.1.7) and ascorbate peroxidase (APX; EC 1.11.1.11) in the later growing stages, indicating Y19 appears to be the more sensitive cultivar and is prone to oxidative stress. The strategic response of antioxidant enzymes activities by Y16 in four different plant development stages (booting, flowering, filling and ripening) resulted in O3 stress-induced antioxidant defense responses, which indicated its higher tolerance to O3 stress. The same patterns of activity of apoplastic SOD and APX isozymes were observed in both Y16 and Y19 cultivars, while POD isozymes differed by cultivar in terms of the pattern of bands. The results of the present study show that O3 tolerance can be improved by regulating apoplastic ROS metabolism through the responses of apoplastic antioxidant enzymes to O3 stress in different plant development stages.
研究了臭氧浓度升高[O₃]对两个不同的臭氧敏感型小麦（普通小麦）品种[扬麦16（Y16）和烟农19（Y19）]的影响，以确定在开放式空气CO₂浓度增高技术（O₃-FACE）条件下不同的质外体抗氧化机制。结果表明，升高的[O₃]（1.5倍环境[O₃]）诱导超氧阴离子（O₂⁻）、羟基自由基（HO）、过氧化氢（H₂O₂）的产生增加以及脂质过氧化，并且这些结果在Y19的质外体中比在Y16的质外体中更明显。质外体抗氧化酶受到发育调控，并且升高的[O₃]的影响取决于两个品种小麦的发育阶段。在品种Y19中，持续的O₃胁迫在生长后期诱导质外体超氧化物歧化酶（SOD；EC 1.15.1.1）、过氧化物酶（POD；EC 1.11.1.7）和抗坏血酸过氧化物酶（APX；EC 1.11.1.11）的活性降低，表明Y19似乎是更敏感的品种，并且易于受到氧化胁迫。Y16在四个不同的植物发育阶段（孕穗期、开花期、灌浆期和成熟期）对抗氧化酶活性的策略性响应导致了O₃胁迫诱导的抗氧化防御反应，这表明其对O₃胁迫具有更高的耐受性。在Y16和Y19品种中均观察到质外体SOD和APX同工酶的相同活性模式，而POD同工酶在条带模式方面因品种而异。本研究结果表明，通过在不同植物发育阶段质外体抗氧化酶对O₃胁迫的响应来调节质外体活性氧代谢，可以提高对O₃的耐受性。
