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Interaction of drought and ozone exposure on isoprene emission from extensively cultivated poplar
Author(s) -
Yuan Xiangyang,
Calatayud Vicent,
Gao Feng,
Fares Silvano,
Paoletti Elena,
Tian Yuan,
Feng Zhaozhong
Publication year - 2016
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/pce.12798
Subject(s) - isoprene , ozone , photosynthesis , horticulture , charcoal , chemistry , botany , biology , organic chemistry , copolymer , polymer
The combined effects of ozone (O 3 ) and drought on isoprene emission were studied for the first time. Young hybrid poplars (clone 546, Populus deltoides cv. 55/56 x P . deltoides cv. Imperial) were exposed to O 3 (charcoal‐filtered air, CF, and non‐filtered air +40 ppb, E‐O 3 ) and soil water stress (well‐watered, WW, and mild drought, MD, one‐third irrigation) for 96 days. Consistent with light‐saturated photosynthesis ( A sat ), intercellular CO 2 concentration ( C i ) and chlorophyll content, isoprene emission depended on drought, O 3 , leaf position and sampling time. Drought stimulated emission (+38.4%), and O 3 decreased it (−40.4%). Ozone increased the carbon cost per unit of isoprene emission. Ozone and drought effects were stronger in middle leaves (13th–15th from the apex) than in upper leaves (6th–8th). Only A sat showed a significant interaction between O 3 and drought. When the responses were up‐scaled to the entire‐plant level, however, drought effects on total leaf area translated into around twice higher emission from WW plants in clean air than in E‐O 3 . Our results suggest that direct effects on plant emission rates and changes in total leaf area may affect isoprene emission from intensively cultivated hybrid poplar under combined MD and O 3 exposure, with important feedbacks for air quality.