State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093, PR China.
State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093, PR China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, PR China.
Environ Pollut. 2018 May;236:296-303. doi: 10.1016/j.envpol.2018.01.093. Epub 2018 Feb 2.
Accelerated industrialization has been increasing releases of chemical precursors of ozone. Ozone concentration has risen nowadays, and it's predicted that this trend will continue in the next few decades. The yield of many ozone-sensitive crops suffers seriously from ozone pollution, and there are abundant reports exploring the damage mechanisms of ozone to these crops, such as winter wheat. However, little is known on how to alleviate these negative impacts to increase grain production under elevated ozone. Nitric oxide, as a bioactive gaseous, mediates a variety of physiological processes and plays a central role in response to biotic and abiotic stresses. In the present study, the accumulation of endogenous nitric oxide in wheat leaves was found to increase in response to ozone. To study the functions of nitric oxide, its precursor sodium nitroprusside was spayed to wheat leaves under ozone pollution. Wheat leaves spayed with sodium nitroprusside accumulated less hydrogen peroxide, malondialdehyde and electrolyte leakage under ozone pollution, which can be accounted for by the higher activities of superoxide dismutase and peroxidase than in leaves treated without sodium nitroprusside. Consequently, net photosynthetic rate of wheat treated using sodium nitroprusside was much higher, and yield reduction was alleviated under ozone fumigation. These findings are important for our understanding of the potential roles of nitric oxide in responses of crops in general and wheat in particular to ozone pollution, and provide a viable method to mitigate the detrimental effects on crop production induced by ozone pollution, which is valuable for keeping food security worldwide.
工业化的加速导致化学臭氧前体物的排放量不断增加。如今，臭氧浓度有所上升，预计在未来几十年内这一趋势还将持续。许多臭氧敏感作物的产量严重受到臭氧污染的影响，有大量的报告探讨了臭氧对这些作物（如冬小麦）的破坏机制。然而，对于如何减轻这些负面影响以增加臭氧升高条件下的粮食产量，人们知之甚少。一氧化氮作为一种生物活性气体，介导着多种生理过程，并在应对生物和非生物胁迫方面发挥着核心作用。在本研究中，发现小麦叶片内内源一氧化氮的积累会因臭氧而增加。为了研究一氧化氮的功能，在臭氧污染下向小麦叶片喷洒了其前体物硝普钠。与未喷洒硝普钠的叶片相比，臭氧污染下喷洒硝普钠的小麦叶片中过氧化氢、丙二醛和电解质泄漏的积累较少，这可以归因于超氧化物歧化酶和过氧化物酶的活性更高。因此，喷洒硝普钠的小麦的净光合速率更高，在臭氧熏蒸下减产得到缓解。这些发现对于我们理解一氧化氮在一般作物特别是小麦对臭氧污染的响应中的潜在作用具有重要意义，并为减轻臭氧污染对作物生产的不利影响提供了一种可行的方法，这对于维护全球粮食安全具有重要价值。
