Emission Trade-Off between Isoprene and Other BVOC Components in Pinus massoniana Saplings May Be Regulated by Content of Chlorophylls, Starch and NSCs under Drought Stress

Abstract

The aim of this work was to study the changes in the BVOCs emission rates and physiological mechanistic response of Pinus massoniana saplings in response to drought stress. Drought stress significantly reduced the emission rates of total BVOCs, monoterpenes, and sesquiterpenes, but had no significant effect on the emission rate of isoprene, which slightly increased under drought stress. A significant negative relationship was observed between the emission rates of total BVOCs, monoterpenes, and sesquiterpenes and the content of chlorophylls, starch, and NSCs, and a positive relationship was observed between the isoprene emission rate and the content of chlorophylls, starch, and NSCs, indicating different control mechanism over the emission of the different components of BVOCs. Under drought stress, the emission trade-off between isoprene and other BVOCs components may be driven by the content of chlorophylls, starch, and NSCs. Considering the inconsistent responses of the different components of BVOCs to drought stress for different plant species, close attention should be paid to the effect of drought stress and global change on plant BVOCs emissions in the future.

Climate-affected multi-decadal variations of biogenic volatile organic compounds in Pinus tabuliformis growth rings

“…Similar correlations were found in studies of diurnal and seasonal monoterpene and isoprene emissions that increased with increasing temperature (Chen et al 2019(Chen et al , 2020. Monoterpene emissions were suggested as a combination of stored and immediately synthesized compounds (Staudt et al 1997), in which emission peaked in warm summer (Peng et al 2011;Bai et al 2017;Huang et al 2023) along with low storage in a specific organ. Another study showed that emissions of diterpenes were detected in different seasons (Chen et al 2019), the seasonal variations of temperature-related emission may be attributed to ecological functions throughout plant development.…”

“…After being synthesized during photosynthesis, monoterpenes were usually stored in specialized storage structures, such as resin canals and secretory cells, and they were partly emitted by leaves to the atmosphere (Niinemets et al 2004;Chen et al 2019). One study in bark of Magnolia officinalis also showed that older trees held higher sesquiterpenes and oxygenated monoterpenes than young trees (Huang et al 2023). Some compounds with increasing trend may hold more storage in special structures accompanied with less emission along with growth stages of Pinus tabuliformis trees.…”