干旱胁迫对植物源挥发性有机物排放影响的研究进展

Effects of Drought Stress on the Emission of Biogenic Volatile Organic Compounds:a Review

随着干旱频率和强度的增加,干旱胁迫对植物源挥发性有机物(BVOCs)的影响受到更多关注。文章综述了干旱胁迫对BVOCs排放影响方面取得的研究进展,探究了干旱胁迫对BVOCs排放的影响。根据近期国内外相关文献,将干旱程度进行划分,研究干旱、复水后对BVOCs排放速率、排放量的影响,探讨复合其他环境因子对BVOCs排放的影响,并探究干旱胁迫对BVOCs排放影响的机理。轻度干旱刺激BVOCs增加排放35%~190%,中度干旱抑制排放8%~97%,重度干旱抑制排放40%~100%。随着干旱程度的加深,BVOCs的排放先增加后减少。对复水的研究总结发现,轻度、中度干旱条件下,异戊二烯和单萜烯的排放速率恢复;重度干旱条件下,异戊二烯快速恢复,单萜烯未恢复。干旱导致BVOCs排放量的估算误差为-70%~40%。净光合速率和气孔导度对水分亏损的敏感度高于BVOCs。BVOCs的释放是植物应对干旱胁迫的保护机制。综述结果可以更好地评估BVOCs排放对当前及未来干旱胁迫情景下的响应,为大气复合污染防控提供支撑。

As the frequency and intensity of drought increase the impact of drought stress on biogenic volatile organic compounds(BVOCs)has received more and more attentions.The research progress in the impact of drought stress on BVOCs emission was mainly reviewed.By characterizing the drought levels,the impact of drought parameters on BVOCs emission rates were reviewed,including the drought severity,rehydration,and other environmental factors.The mechanism of drought stress on BVOCs emission were also summarized and discussed.The existing studies can be divided into three categories,based on duration of dress and loss of soil water,including mild,moderate and severe levels.Previous studies found that BVOCs emission rates increased by 35%~190%during mild drought,but decreased by 8%~97%during moderate drought and by 40%~100%during severe droughts.Meanwhile,the emission rates of BVOCs were expected to increase at the beginning of drought and then decrease,because the release of BVOCs at certain degree can protect plants from drought stress.Previous studies on rehydration found that,under mild and moderate drought,the emission rates of isoprene and monoterpene were recovered after mild and moderate stress.Under severe drought conditions,the isoprene emission was recovered quickly,but monoterpene emission was not recovered.Studies on the mechanism of drought stress found the net photosynthetic rate and stomatal conductance were more sensitive to water loss than BVOC emissions.The uncertainties from drought stress on BVOCs emissions inventory varied by-70%~40%.The results of this review can better assess the response of BVOCs emissions from drought,and supports the prevention and control of complex air pollution in China.