Stomatal and mesophyll conductance are dominant limitations to photosynthesis in response to heat stress during severe drought in a temperate and a tropical tree species

dc.contributor.authorZhu, Lingling
dc.contributor.authorLi, Hongcheng
dc.contributor.authorThorpe, Michael
dc.contributor.authorHocart, Charles
dc.contributor.authorSong, Xin
dc.description.abstractKey message: Stomatal and mesophyll conductance were the dominant limitations to photosynthesis in response to heat stress during severe drought in both a temperate and a tropical tree species. Abstract: Drought and heat stress cause a significant reduction in forest primary production. The current study aims to determine the major limitations to photosynthesis in a temperate and tropical tree species experiencing a combination of drought and heat stress; an increasingly common situation in the face of climate change. Two tree species, one temperate (Fraxinus chinensis) and the other tropical (Radermachera sinica) were subjected in growth chambers to a 2-day heat stress of 40 °C during ca. 2-week period of drought, followed by re-watering. The limitations by three factors that affect photosynthesis (stomatal and mesophyll conductance, and biochemical processes) were partitioned based on measurements of gas exchange, net assimilation rate—intercellular CO concentration (A —C ) curves and chlorophyll fluorescence. Under the drought-only condition, photosynthesis was primarily limited by stomatal conductance in both species. Unexpectedly, heat stress did not further reduce photosynthesis during drought in either tree species. In both species, carbon assimilation during drought and added heat stress was primarily limited by stomatal and mesophyll conductance. Drought decreased mesophyll conductance in both species but the effects were more pronounced in the tropical tree species, R. sinica. Biochemical limitation remained low throughout the stress period. These results suggest the importance of balancing water conservation and transpirational cooling in the diffusive pathway in response to, not only drought, but also the combination of water and heat stress in forest trees. 2 net ien_AU
dc.description.sponsorshipThe research was supported by Shenzhen Municipal Peacock Team Program (KQTD2017032715165926) from Science and Technology Innovation Commission of the Shenzhen City and a general program from the National Natural Science Foundation of China (31770435) to X.S., and the China Postdoctoral Science Foundation (2019M652760) to L.Z.en_AU
dc.rights© The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2021en_AU
dc.sourceTrees (Structure and Function)en_AU
dc.subjectHigh temperatureen_AU
dc.subjectWater defciten_AU
dc.subjectWater use effciencyen_AU
dc.subjectCarbon exchangeen_AU
dc.titleStomatal and mesophyll conductance are dominant limitations to photosynthesis in response to heat stress during severe drought in a temperate and a tropical tree speciesen_AU
dc.typeJournal articleen_AU
local.contributor.affiliationZhu, Lingling, Shenzhen Universityen_AU
local.contributor.affiliationLi, Hongcheng, Shenzhen Universityen_AU
local.contributor.affiliationThorpe, Michael, College of Science, ANUen_AU
local.contributor.affiliationHocart, Charles, College of Science, ANUen_AU
local.contributor.affiliationSong, Xin, Shenzhen Universityen_AU
local.contributor.authoruidThorpe, Michael, u1815101en_AU
local.contributor.authoruidHocart, Charles, u8101127en_AU
local.description.notesImported from ARIESen_AU
local.identifier.absfor310806 - Plant physiologyen_AU
local.identifier.absseo280112 - Expanding knowledge in the health sciencesen_AU
local.type.statusPublished Versionen_AU