短期干旱胁迫对马尾松排放挥发性有机物的影响

Impact of short-term drought stress on volatile organic compounds emissions from Pinus massoniana

为探究干旱环境对BVOCs排放的影响,应用动态封闭式采样系统和热脱附-气相色谱-飞行质谱仪,对短期干旱胁迫作用下马尾松的BVOCs排放进行了实验室测量,定量分析BVOCs排放速率和排放组成的变化.结果表明,干旱胁迫时异戊二烯的排放受到抑制,排放速率降低约50%;单萜烯和倍半萜烯的排放水平增强,排放速率分别为137.85和0.98μg/(m^2·h),是未受胁迫时的2.9和2.0倍.除反式-α-香柠檬烯外,干旱胁迫促进各单萜烯和倍半萜烯化合物的排放,是未受胁迫时的1.3~42.4倍,其中3-蒈烯排放的响应最敏感,α-葑烯、α-水芹烯和石竹烯的响应最弱.干旱胁迫时单萜烯和倍半萜烯的排放组成有所变化,但主导的化合物种类不变,单萜烯以α-蒎烯、香桧烯和β-蒎烯为主,占比分别为48%、17%和17%;倍半萜烯以石竹烯和长叶烯为主,占比分别为57%和34%.

To explore the impact of drought on BVOC emissions,dynamic enclosure system and TD-GC-TOFMS were used to conduct laboratory measurements of BVOC emission from Pinus massoniana under short-term drought stress.The changes in emission rates and composition were analyzed quantitatively.The results showed that emission of isoprene was inhibited under drought stress,with a drop of around 50%in emission rate.Monoterpene and sesquiterpene emission rates were enhanced to 137.85μg/(m^2·h)and 0.98μg/(m^2·h)which were 2.9 and 2.0 times as high as those without stress,respectively.Except trans-α-bergamotene,emissions of all the detected monoterpene and sesquiterpene compounds were promoted under drought stress.Those emission rates were 1.3~42.4 times as high as those without stress.Among them,3-carene emission had the most sensitive response to drought stress,whileα-fenchene,α-phellandrene,and trans-caryophyllene had the lowest sensitivity.Under drought stress,the emission compositions of monoterpene and sesquiterpene were changed,but the dominant compounds remained the same.The main components of monoterpene wereα-pinene,sabinene,andβ-pinene,accounting for 48%,17%,and 17%in the total monoterpene emissions,respectively.Trans-caryophyllene and longifolene dominated sesquiterpene emissions with contributions of 57%and 34%,respectively.