ORCID Profile
0000-0002-4983-5645
Current Organisation
Fujian Normal University
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: Wiley
Date: 16-05-2022
DOI: 10.1111/GCB.16221
Abstract: Increases in terrestrial water‐use efficiency (WUE) have been reported in many studies, pointing to potential changes in physiological forcing of global carbon and hydrological cycles. However, gains in WUE are of uncertain magnitude over longer (i.e. years) periods of time largely owing to difficulties in accounting for structural and physiological acclimation. 13 C signatures (i.e. δ 13 C) of plant organic matter have long been used to estimate WUE at temporal scales ranging from days to centuries. Mesophyll conductance is a key uncertainty in estimated WUE owing to its influence on diffusion of CO 2 to sites of carboxylation. Here we apply new knowledge of mesophyll conductance to 464 δ 13 C chronologies in tree‐rings of 143 species spanning global biomes. Adjusted for mesophyll conductance, gains in WUE during the 20th century (0.15 ppm year −1 ) were considerably smaller than those estimated from conventional modelling (0.26 ppm year −1 ). Across the globe, mean sensitivity of WUE to atmospheric CO 2 was 0.15 ppm ppm −1 . Ratios of internal‐to‐atmospheric CO 2 (on a mole fraction basis c i / c a ) in leaves were mostly constant over time but differed among biomes and plant taxa—highlighting the significance of both plant structure and physiology. Together with synchronized responses in stomatal and mesophyll conductance, our results suggest that ratios of chloroplastic‐to‐atmospheric CO 2 ( c c / c a ) are constrained over time. We conclude that forest WUE may have not increased as much as previously suggested and that projections of future climate forcing via CO 2 fertilization may need to be adjusted accordingly.
Publisher: Wiley
Date: 02-10-2017
DOI: 10.1111/NPH.14816
Abstract: It has been 75 yr since leaf respiratory metabolism in the light (day respiration) was identified as a low‐flux metabolic pathway that accompanies photosynthesis. In principle, it provides carbon backbones for nitrogen assimilation and evolves CO 2 and thus impacts on plant carbon and nitrogen balances. However, for a long time, uncertainties have remained as to whether techniques used to measure day respiratory efflux were valid and whether day respiration responded to environmental gaseous conditions. In the past few years, significant advances have been made using carbon isotopes, ‘omics’ analyses and surveys of respiration rates in mesocosms or ecosystems. There is substantial evidence that day respiration should be viewed as a highly dynamic metabolic pathway that interacts with photosynthesis and photorespiration and responds to atmospheric CO 2 mole fraction. The view of leaf day respiration as a constant and/or negligible parameter of net carbon exchange is now outdated and it should now be regarded as a central actor of plant carbon‐use efficiency. Contents Summary 986 I. Introduction 987 II. Pioneering metabolic studies of day respiration with 14 C 987 III. Metabolic flux pattern of day respiration 988 IV. Significance of day respiration for leaf N assimilation 991 V. Significance of day respiration for leaf gas exchange 992 VI. Is day respiration influenced by CO 2 mole fraction? 995 VII. Significance of day respiration at the plant and ecosystem levels 997 VIII. Conclusions and perspectives 998 References 998
Publisher: Wiley
Date: 25-10-2020
DOI: 10.1111/NPH.16958
Abstract: Carbon isotope discrimination (Δ) has been used widely to infer intrinsic water‐use efficiency (iWUE) of C 3 plants, a key parameter linking carbon and water fluxes. Despite the essential role of mesophyll conductance ( g m ) in photosynthesis and Δ, its effect on Δ‐based predictions of iWUE has generally been neglected. Here, we derive a mathematical expression of iWUE as a function of Δ that includes g m (iWUE mes ) and exploits the g m ‐stomatal conductance ( g sc ) relationship across drought‐stress levels and plant functional groups (deciduous or semideciduous woody, evergreen woody and herbaceous species) in a global database. iWUE mes was further validated with an independent dataset of online‐Δ and CO 2 and H 2 O gas exchange measurements with seven species. Drought stress reduced g sc and g m by nearly one‐half across all plant functional groups, but had no significant effect on the g sc : g m ratio, with a well supported value of 0.79 ± 0.07 (95% CI, n = 198). g m was negatively correlated to iWUE. Incorporating the g sc : g m ratio greatly improved estimates of iWUE, compared with calculations that assumed infinite g m . The inclusion of the g sc : g m ratio, fixed at 0.79 when g m was unknown, proved desirable to eliminate significant errors in estimating iWUE from Δ across various C 3 vegetation types.
Publisher: Wiley
Date: 20-03-2017
DOI: 10.1111/NPH.14527
Publisher: Oxford University Press (OUP)
Date: 15-12-2022
Abstract: Evaluating leaf day respiration rate (RL), which is believed to differ from that in the dark (RDk), is essential for predicting global carbon cycles under climate change. Several studies have suggested that atmospheric CO2 impacts RL. However, the magnitude of such an impact and associated mechanisms remain uncertain. To explore the CO2 effect on RL, wheat (Triticum aestivum) and sunflower (Helianthus annuus) plants were grown under ambient (410 ppm) and elevated (820 ppm) CO2 mole fraction ([CO2]). RL was estimated from combined gas exchange and chlorophyll fluorescence measurements using the Kok method, the Kok-Phi method, and a revised Kok method (Kok-Cc method). We found that elevated growth [CO2] led to an 8.4% reduction in RL and a 16.2% reduction in RDk in both species, in parallel to decreased leaf N and chlorophyll contents at elevated growth [CO2]. We also looked at short-term CO2 effects during gas exchange experiments. Increased RL or RL/RDk at elevated measurement [CO2] were found using the Kok and Kok-Phi methods, but not with the Kok-Cc method. This discrepancy was attributed to the unaccounted changes in Cc in the former methods. We found that the Kok and Kok-Phi methods underestimate RL and overestimate the inhibition of respiration under low irradiance conditions of the Kok curve, and the inhibition of RL was only 6%, representing 26% of the apparent Kok effect. We found no significant long-term CO2 effect on RL/RDk, originating from a concurrent reduction in RL and RDk at elevated growth [CO2], and likely mediated by acclimation of nitrogen metabolism.
Publisher: Cold Spring Harbor Laboratory
Date: 06-07-2020
DOI: 10.1101/2020.07.06.188920
Abstract: The carbon isotope discrimination (Δ) has been used widely to infer intrinsic water-use efficiency (iWUE) of C 3 plants, a key parameter linking carbon and water fluxes. Despite the essential role of mesophyll conductance ( g m ) in photosynthesis and Δ, its effect on Δ-based predictions of iWUE has generally been neglected. Here, we derive a mathematical expression of iWUE as a function of Δ that includes g m (iWUE mes ) and exploits the g m -stomatal conductance ( g sc ) relationship across drought-stress levels and plant functional groups (deciduous or semi-deciduous woody, evergreen woody and herbaceous species) in a global database. iWUE mes was further validated with an independent dataset of online-Δ and CO 2 and H 2 O gas exchange measurements with seven species. Drought stress reduced g sc by 52% and g m by 45% averaged over all plant functional groups, but had no significant effect on the g sc / g m ratio, suggesting a well-constrained g sc / g m ratio of 0.79±0.07 (95%CI, n =198) across plant functional groups and drought-stress treatments. Due in part to the synchronous behavior of g sc and g m , g m was negatively correlated to iWUE. Incorporating the g sc / g m ratio in the iWUE mes model significantly improved the estimation of iWUE compared to the simple model. The inclusion of g m effects, even using a fixed g sc / g m ratio of 0.79 when g m is unknown, proved desirable to eliminate significant bias in estimating iWUE from Δ across various C 3 vegetation types.
No related grants have been discovered for Xiao Ying Gong.