共查询到20条相似文献，搜索用时 0 毫秒
1.
Kristine Y. Crous John E. Drake Michael J. Aspinwall Robert E. Sharwood Mark G. Tjoelker Oula Ghannoum 《Global Change Biology》2018,24(10):4626-4644
Climate is an important factor limiting tree distributions and adaptation to different thermal environments may influence how tree populations respond to climate warming. Given the current rate of warming, it has been hypothesized that tree populations in warmer, more thermally stable climates may have limited capacity to respond physiologically to warming compared to populations from cooler, more seasonal climates. We determined in a controlled environment how several provenances of widely distributed Eucalyptus tereticornis and E. grandis adjusted their photosynthetic capacity to +3.5°C warming along their native distribution range (~16–38°S) and whether climate of seed origin of the provenances influenced their response to different growth temperatures. We also tested how temperature optima (Topt) of photosynthesis and Jmax responded to higher growth temperatures. Our results showed increased photosynthesis rates at a standardized temperature with warming in temperate provenances, while rates in tropical provenances were reduced by about 40% compared to their temperate counterparts. Temperature optima of photosynthesis increased as provenances were exposed to warmer growth temperatures. Both species had ~30% reduced photosynthetic capacity in tropical and subtropical provenances related to reduced leaf nitrogen and leaf Rubisco content compared to temperate provenances. Tropical provenances operated closer to their thermal optimum and came within 3% of the Topt of Jmax during the daily temperature maxima. Hence, further warming may negatively affect C uptake and tree growth in warmer climates, whereas eucalypts in cooler climates may benefit from moderate warming. 相似文献
2.
While temperature responses of photosynthesis and plant respiration are known to acclimate over time in many species, few studies have been designed to directly compare process‐level differences in acclimation capacity among plant types. We assessed short‐term (7 day) temperature acclimation of the maximum rate of Rubisco carboxylation (Vcmax), the maximum rate of electron transport (Jmax), the maximum rate of phosphoenolpyruvate carboxylase carboxylation (Vpmax), and foliar dark respiration (Rd) in 22 plant species that varied in lifespan (annual and perennial), photosynthetic pathway (C3 and C4), and climate of origin (tropical and nontropical) grown under fertilized, well‐watered conditions. In general, acclimation to warmer temperatures increased the rate of each process. The relative increase in different photosynthetic processes varied by plant type, with C3 species tending to preferentially accelerate CO2‐limited photosynthetic processes and respiration and C4 species tending to preferentially accelerate light‐limited photosynthetic processes under warmer conditions. Rd acclimation to warmer temperatures caused a reduction in temperature sensitivity that resulted in slower rates at high leaf temperatures. Rd acclimation was similar across plant types. These results suggest that temperature acclimation of the biochemical processes that underlie plant carbon exchange is common across different plant types, but that acclimation to warmer temperatures tends to have a relatively greater positive effect on the processes most limiting to carbon assimilation, which differ by plant type. The acclimation responses observed here suggest that warmer conditions should lead to increased rates of carbon assimilation when water and nutrients are not limiting. 相似文献
3.
Photosynthetic temperature acclimation could strongly affect coupled vegetation–atmosphere feedbacks in the global carbon cycle, especially as the climate warms. Thermal acclimation of photosynthesis can be modelled as changes in the parameters describing the direct effect of temperature on photosynthetic capacity (i.e., activation energy, Ea; deactivation energy, Hd; entropy parameter, ΔS) or the basal value of photosynthetic capacity (i.e., photosynthetic capacity measured at 25°C). However, the impact of acclimating these parameters (individually or in combination) on vegetative carbon gain is relatively unexplored. Here we compare the ability of 66 photosynthetic temperature acclimation scenarios to improve the ability of a spatially explicit canopy carbon flux model, MAESTRA, to predict eddy covariance data from a loblolly pine forest. We show that: (1) incorporating seasonal temperature acclimation of basal photosynthetic capacity improves the model's ability to capture seasonal changes in carbon fluxes and outperforms acclimation of other single factors (i.e., Ea or ΔS alone); (2) multifactor scenarios of photosynthetic temperature acclimation provide minimal (if any) improvement in model performance over single factor acclimation scenarios; (3) acclimation of Ea should be restricted to the temperature ranges of the data from which the equations are derived; and (4) model performance is strongly affected by the Hd parameter. We suggest that a renewed effort be made into understanding whether basal photosynthetic capacity, Ea, Hd and ΔS co‐acclimate across broad temperature ranges to determine whether and how multifactor thermal acclimation of photosynthesis occurs. 相似文献
4.
Artur Stefanski Raimundo Bermudez Kerrie M. Sendall Rebecca A. Montgomery Peter B. Reich 《Global Change Biology》2020,26(2):746-759
Photosynthetic biochemical limitation parameters (i.e., Vcmax, Jmax and Jmax:Vcmax ratio) are sensitive to temperature and water availability, but whether these parameters in cold climate species at biome ecotones are positively or negatively influenced by projected changes in global temperature and water availability remains uncertain. Prior exploration of this question has largely involved greenhouse based short‐term manipulative studies with mixed results in terms of direction and magnitude of responses. To address this question in a more realistic context, we examined the effects of increased temperature and rainfall reduction on the biochemical limitations of photosynthesis using a long‐term chamber‐less manipulative experiment located in northern Minnesota, USA. Nine tree species from the boreal‐temperate ecotone were grown in natural neighborhoods under ambient and elevated (+3.4°C) growing season temperatures and ambient or reduced (≈40% of rainfall removed) summer rainfall. Apparent rubisco carboxylation and RuBP regeneration standardized to 25°C (Vcmax25°C and Jmax25°C, respectively) were estimated based on ACi curves measured in situ over three growing seasons. Our primary objective was to test whether species would downregulate Vcmax25°C and Jmax25°C in response to warming and reduced rainfall, with such responses expected to be greatest in species with the coldest and most humid native ranges, respectively. These hypotheses were not supported, as there were no overall main treatment effects on Vcmax25°C or Jmax25°C (p > .14). However, Jmax:Vcmax ratio decreased significantly with warming (p = .0178), whereas interactions between warming and rainfall reduction on the Jmax25°C to Vcmax25°C ratio were not significant. The insensitivity of photosynthetic parameters to warming contrasts with many prior studies done under larger temperature differentials and often fixed daytime temperatures. In sum, plants growing in relatively realistic conditions under naturally varying temperatures and soil moisture levels were remarkably insensitive in terms of their Jmax25°C and Vcmax25°C when grown at elevated temperatures, reduced rainfall, or both combined. 相似文献
5.
Benedict M. Long Nur H. A. Bahar Lasantha K. Weerasinghe Danielle Creek John R. Evans Peter B. Reich Owen K. Atkin 《Global Change Biology》2017,23(7):2783-2800
Understanding of the extent of acclimation of light‐saturated net photosynthesis (An) to temperature (T), and associated underlying mechanisms, remains limited. This is a key knowledge gap given the importance of thermal acclimation for plant functioning, both under current and future higher temperatures, limiting the accuracy and realism of Earth system model (ESM) predictions. Given this, we analysed and modelled T‐dependent changes in photosynthetic capacity in 10 wet‐forest tree species: six from temperate forests and four from tropical forests. Temperate and tropical species were each acclimated to three daytime growth temperatures (Tgrowth): temperate – 15, 20 and 25 °C; tropical – 25, 30 and 35 °C. CO2 response curves of An were used to model maximal rates of RuBP (ribulose‐1,5‐bisphosphate) carboxylation (Vcmax) and electron transport (Jmax) at each treatment's respective Tgrowth and at a common measurement T (25 °C). SDS‐PAGE gels were used to determine abundance of the CO2‐fixing enzyme, Rubisco. Leaf chlorophyll, nitrogen (N) and mass per unit leaf area (LMA) were also determined. For all species and Tgrowth, An at current atmospheric CO2 partial pressure was Rubisco‐limited. Across all species, LMA decreased with increasing Tgrowth. Similarly, area‐based rates of Vcmax at a measurement T of 25 °C (Vcmax25) linearly declined with increasing Tgrowth, linked to a concomitant decline in total leaf protein per unit leaf area and Rubisco as a percentage of leaf N. The decline in Rubisco constrained Vcmax and An for leaves developed at higher Tgrowth and resulted in poor predictions of photosynthesis by currently widely used models that do not account for Tgrowth‐mediated changes in Rubisco abundance that underpin the thermal acclimation response of photosynthesis in wet‐forest tree species. A new model is proposed that accounts for the effect of Tgrowth‐mediated declines in Vcmax25 on An, complementing current photosynthetic thermal acclimation models that do not account for T sensitivity of Vcmax25. 相似文献
6.
Sanu Shameer Yu Wang Pedro Bota R. George Ratcliffe Stephen P. Long Lee J. Sweetlove 《The Plant journal : for cell and molecular biology》2022,109(1):295-313
While flux balance analysis (FBA) provides a framework for predicting steady-state leaf metabolic network fluxes, it does not readily capture the response to environmental variables without being coupled to other modelling formulations. To address this, we coupled an FBA model of 903 reactions of soybean (Glycine max) leaf metabolism with e-photosynthesis, a dynamic model that captures the kinetics of 126 reactions of photosynthesis and associated chloroplast carbon metabolism. Successful coupling was achieved in an iterative formulation in which fluxes from e-photosynthesis were used to constrain the FBA model and then, in turn, fluxes computed from the FBA model used to update parameters in e-photosynthesis. This process was repeated until common fluxes in the two models converged. Coupling did not hamper the ability of the kinetic module to accurately predict the carbon assimilation rate, photosystem II electron flux, and starch accumulation of field-grown soybean at two CO2 concentrations. The coupled model also allowed accurate predictions of additional parameters such as nocturnal respiration, as well as analysis of the effect of light intensity and elevated CO2 on leaf metabolism. Predictions included an unexpected decrease in the rate of export of sucrose from the leaf at high light, due to altered starch–sucrose partitioning, and altered daytime flux modes in the tricarboxylic acid cycle at elevated CO2. Mitochondrial fluxes were notably different between growing and mature leaves, with greater anaplerotic, tricarboxylic acid cycle and mitochondrial ATP synthase fluxes predicted in the former, primarily to provide carbon skeletons and energy for protein synthesis. 相似文献
7.
Yongguang Zhang Luis Guanter Joseph A. Berry Joanna Joiner Christiaan van der Tol Alfredo Huete Anatoly Gitelson Maximilian Voigt Philipp Köhler 《Global Change Biology》2014,20(12):3727-3742
Photosynthesis simulations by terrestrial biosphere models are usually based on the Farquhar's model, in which the maximum rate of carboxylation (Vcmax) is a key control parameter of photosynthetic capacity. Even though Vcmax is known to vary substantially in space and time in response to environmental controls, it is typically parameterized in models with tabulated values associated to plant functional types. Remote sensing can be used to produce a spatially continuous and temporally resolved view on photosynthetic efficiency, but traditional vegetation observations based on spectral reflectance lack a direct link to plant photochemical processes. Alternatively, recent space‐borne measurements of sun‐induced chlorophyll fluorescence (SIF) can offer an observational constraint on photosynthesis simulations. Here, we show that top‐of‐canopy SIF measurements from space are sensitive to Vcmax at the ecosystem level, and present an approach to invert Vcmax from SIF data. We use the Soil‐Canopy Observation of Photosynthesis and Energy (SCOPE) balance model to derive empirical relationships between seasonal Vcmax and SIF which are used to solve the inverse problem. We evaluate our Vcmax estimation method at six agricultural flux tower sites in the midwestern US using spaced‐based SIF retrievals. Our Vcmax estimates agree well with literature values for corn and soybean plants (average values of 37 and 101 μmol m?2 s?1, respectively) and show plausible seasonal patterns. The effect of the updated seasonally varying Vcmax parameterization on simulated gross primary productivity (GPP) is tested by comparing to simulations with fixed Vcmax values. Validation against flux tower observations demonstrate that simulations of GPP and light use efficiency improve significantly when our time‐resolved Vcmax estimates from SIF are used, with R2 for GPP comparisons increasing from 0.85 to 0.93, and for light use efficiency from 0.44 to 0.83. Our results support the use of space‐based SIF data as a proxy for photosynthetic capacity and suggest the potential for global, time‐resolved estimates of Vcmax. 相似文献
8.
Steven D. Allison Adriana L. Romero‐Olivares Ying Lu John W. Taylor Kathleen K. Treseder 《Global Change Biology》2018,24(7):2884-2897
The magnitude and direction of carbon cycle feedbacks under climate warming remain uncertain due to insufficient knowledge about the temperature sensitivities of soil microbial processes. Enzymatic rates could increase at higher temperatures, but this response could change over time if soil microbes adapt to warming. We used the Arrhenius relationship, biochemical transition state theory, and thermal physiology theory to predict the responses of extracellular enzyme Vmax and Km to temperature. Based on these concepts, we hypothesized that Vmax and Km would correlate positively with each other and show positive temperature sensitivities. For enzymes from warmer environments, we expected to find lower Vmax, Km, and Km temperature sensitivity but higher Vmax temperature sensitivity. We tested these hypotheses with isolates of the filamentous fungus Neurospora discreta collected from around the globe and with decomposing leaf litter from a warming experiment in Alaskan boreal forest. For Neurospora extracellular enzymes, Vmax Q10 ranged from 1.48 to 2.25, and Km Q10 ranged from 0.71 to 2.80. In agreement with theory, Vmax and Km were positively correlated for some enzymes, and Vmax declined under experimental warming in Alaskan litter. However, the temperature sensitivities of Vmax and Km did not vary as expected with warming. We also found no relationship between temperature sensitivity of Vmax or Km and mean annual temperature of the isolation site for Neurospora strains. Declining Vmax in the Alaskan warming treatment implies a short‐term negative feedback to climate change, but the Neurospora results suggest that climate‐driven changes in plant inputs and soil properties are important controls on enzyme kinetics in the long term. Our empirical data on enzyme Vmax, Km, and temperature sensitivities should be useful for parameterizing existing biogeochemical models, but they reveal a need to develop new theory on thermal adaptation mechanisms. 相似文献
9.
Tingbing Zhu Xuemei Li Xingbing Wu Deguo Yang 《Zeitschrift fur angewandte Ichthyologie》2019,35(6):1281-1285
Schizopygopsis younghusbandi is an endemic fish of Tibet characterized by slow growth. Artificial stock enhancement was applied to rebuild the natural population of S. younghusbandi in recent years. However, the optimal growth temperature and thermal tolerance of S. younghusbandi has not been studied, which restricts the production of S. younghusbandi fingerling for stock enhancement. The purpose of this paper is to determine the growth, critical thermal maximum (CTMax), lethal thermal maximum (LTMax) and acclimation response ratio (ARR) of S. younghusbandi juveniles (body weight 5.7 ± 1.2 g) at three acclimation temperature levels (10, 15, 20°C). The results showed that acclimation temperature significantly affected the growth, CTMax, LTMax and ARR of the experimental fish. Largest final weight (7.5 ± 2.3 g) was recorded in 15°C group. At a heating rate of 1°C/30 min, CTMax ranged from 30.98 to 32.01°C and LTMax ranged from 31.76 to 32.31°C in the three acclimation temperatures. Schizopygopsis younghusbandi had lower ARR value (0.097) than most other fish species. Low ARR value indicates that S. younghusbandi may have narrower thermal tolerance range and weaker acclimation ability to global warming. For successful aquaculture of S. younghusbandi juveniles, temperature should be maintained around 15°C. 相似文献
10.
Jinquan Li Ming Nie Elise Pendall Peter B. Reich Junmin Pei Nam Jin Noh Ting Zhu Bo Li Changming Fang 《Global Change Biology》2020,26(3):1873-1885
Determining soil carbon (C) responses to rising temperature is critical for projections of the feedbacks between terrestrial ecosystems, C cycle, and climate change. However, the direction and magnitude of this feedback remain highly uncertain due largely to our limited understanding of the spatial heterogeneity of soil C decomposition and its temperature sensitivity. Here we quantified C decomposition and its response to temperature change with an incubation study of soils from 203 sites across tropical to boreal forests in China spanning a wide range of latitudes (18°16′ to 51°37′N) and longitudes (81°01′ to 129°28′E). Mean annual temperature (MAT) and mean annual precipitation primarily explained the biogeographic variation in the decomposition rate and temperature sensitivity of soils: soil C decomposition rate decreased from warm and wet forests to cold and dry forests, while Q10‐MAT (standardized to the MAT of each site) values displayed the opposite pattern. In contrast, biological factors (i.e. plant productivity and soil bacterial diversity) and soil factors (e.g. clay, pH, and C availability of microbial biomass C and dissolved organic C) played relatively small roles in the biogeographic patterns. Moreover, no significant relationship was found between Q10‐MAT and soil C quality, challenging the current C quality–temperature hypothesis. Using a single, fixed Q10‐MAT value (the mean across all forests), as is usually done in model predictions, would bias the estimated soil CO2 emissions at a temperature increase of 3.0°C. This would lead to overestimation of emissions in warm biomes, underestimation in cold biomes, and likely significant overestimation of overall C release from soil to the atmosphere. Our results highlight that climate‐related biogeographic variation in soil C responses to temperature needs to be included in next‐generation C cycle models to improve predictions of C‐climate feedbacks. 相似文献
11.
Desiccation resistance, the ability of an organism to reduce water loss, is an essential trait in arid habitats. Drought frequency in tropical regions is predicted to increase with climate change, and small ectotherms are often under a strong desiccation risk. We tested hypotheses regarding the underexplored desiccation potential of tropical insects. We measured desiccation resistance in 82 ant species from a Panama rainforest by recording the time ants can survive desiccation stress. Species' desiccation resistance ranged from 0.7 h to 97.9 h. We tested the desiccation adaptation hypothesis, which predicts higher desiccation resistance in habitats with higher vapor pressure deficit (VPD) – the drying power of the air. In a Panama rainforest, canopy microclimates averaged a VPD of 0.43 kPa, compared to a VPD of 0.05 kPa in the understory. Canopy ants averaged desiccation resistances 2.8 times higher than the understory ants. We tested a number of mechanisms to account for desiccation resistance. Smaller insects should desiccate faster given their higher surface area to volume ratio. Desiccation resistance increased with ant mass, and canopy ants averaged 16% heavier than the understory ants. A second way to increase desiccation resistance is to carry more water. Water content was on average 2.5% higher in canopy ants, but total water content was not a good predictor of ant desiccation resistance or critical thermal maximum (CTmax), a measure of an ant's thermal tolerance. In canopy ants, desiccation resistance and CTmax were inversely related, suggesting a tradeoff, while the two were positively correlated in understory ants. This is the first community level test of desiccation adaptation hypothesis in tropical insects. Tropical forests do contain desiccation‐resistant species, and while we cannot predict those simply based on their body size, high levels of desiccation resistance are always associated with the tropical canopy. 相似文献
12.
E‐Jiao Wu Yan‐Ping Wang Lurwanu Yahuza Meng‐Han He Dan‐Li Sun Yan‐Mei Huang Yu‐Chan Liu Li‐Na Yang Wen Zhu Jiasui Zhan 《Evolutionary Applications》2020,13(4):768-780
Temperature plays a multidimensional role in host–pathogen interactions. As an important element of climate change, elevated world temperature resulting from global warming presents new challenges to sustainable disease management. Knowledge of pathogen adaptation to global warming is needed to predict future disease epidemiology and formulate mitigating strategies. In this study, 21 Phytophthora infestans isolates originating from seven thermal environments were acclimated for 200 days under stepwise increase or decrease of experimental temperatures and evolutionary responses of the isolates to the thermal changes were evaluated. We found temperature acclimation significantly increased the fitness and genetic adaptation of P. infestans isolates at both low and high temperatures. Low‐temperature acclimation enforced the countergradient adaptation of the pathogen to its past selection and enhanced the positive association between the pathogen's intrinsic growth rate and aggressiveness. At high temperatures, we found that pathogen growth collapsed near the maximum temperature for growth, suggesting a thermal niche boundary may exist in the evolutionary adaptation of P. infestans. These results indicate that pathogens can quickly adapt to temperature shifts in global warming. If this is associated with environmental conditions favoring pathogen spread, it will threaten future food security and human health and require the establishment of mitigating actions. 相似文献
13.
Alessandro A. Fortunato Daniel Debona Arthur M. A. Bernardeli Fabrício A. Rodrigues 《Journal of Phytopathology》2015,163(9):731-742
Target spot, caused by the fungus Corynespora cassiicola, has become a serious foliar disease in soybean production in the Brazilian Cerrado. Information in the literature regarding the biochemical defence responses of soybean to C. cassiicola infection is rare. Therefore, the objective of this study was to determine the biochemical features associated with soybean resistance to target spot. The activities of chitinases (CHI), β‐1‐3‐glucanases (GLU), phenylalanine ammonia‐lyases (PAL), peroxidases (POX), polyphenol oxidases (PPO) and lipoxygenases (LOX), as well as the concentrations of total soluble phenolics (TSP) and lignin‐thioglycolic acid (LTGA) derivatives, were determined in soybean leaves from both a resistant (FUNDACEP 59) and a susceptible (TMG 132) cultivar. The target spot severity, number of lesions per cm2 of leaflet and area under the disease progress curve were significantly lower for plants from cv. FUNDACEP 59 compared to plants from cv. TMG 132. The GLU, CHI, PAL, POX and PPO activities and the concentration of LTGA derivatives increased significantly, whereas LOX activity decreased significantly on the leaves infected by C. cassiicola. Inoculated plants from cv. FUNDACEP 59 showed a higher PPO activity and concentrations of TSP and LTGA derivatives at 4 and 6 days after inoculation compared to plants from cv. TMG 132. In conclusion, the results of this study demonstrated that the defence‐related enzyme activities increased upon C. cassiicola infection, regardless of the basal level of resistance of the cultivar studied. The increases in PPO activity and concentrations of TSP and LTGA derivatives, but lower LOX activity, at early stages of C. cassiicola infection were highly associated with soybean resistance to target spot. 相似文献
14.
15.
The genome of each species contains as high as 8% of genes that are uniquely present in that species. Little is known about the functional significance of these so‐called species specific or orphan genes. The Arabidopsis thaliana gene Qua‐Quine Starch (QQS) is species specific. Here, we show that altering QQS expression in Arabidopsis affects carbon partitioning to both starch and protein. We hypothesized QQS may be conserved in a feature other than primary sequence, and as such could function to impact composition in another species. To test the potential of QQS in affecting composition in an ectopic species, we introduced QQS into soybean. Soybean T1 lines expressing QQS have up to 80% decreased leaf starch and up to 60% increased leaf protein; T4 generation seeds from field‐grown plants contain up to 13% less oil, while protein is increased by up to 18%. These data broaden the concept of QQS as a modulator of carbon and nitrogen allocation, and demonstrate that this species‐specific gene can affect the seed composition of an agronomic species thought to have diverged from Arabidopsis 100 million years ago. 相似文献
16.
Vinícius Souza Rios Jonas Alberto Rios Carlos Eduardo Aucique‐Pérez Patrícia Ricardino Silveira Aline Vieira Barros Fabrício Ávila Rodrigues 《Journal of Phytopathology》2018,166(2):75-85
Asian soybean rust (ASR), caused by Phakopsora pachyrhizi, is one of the most important foliar diseases affecting soybean production worldwide. This study aimed to investigate the photosynthetic performance (leaf gas exchange, chlorophyll (Chl) a fluorescence images and photosynthetic pigment pools) of soybean plants sprayed with Acibenzolar‐S‐Methyl (ASM) and the fungicide epoxiconazole + pyraclostrobin (Epo+Pyr) and further inoculated with P. pachyrhizi. The ASR symptoms progressed much faster on the leaves of plants from the control treatment (water spray) in comparison with the ASM and Epo+Pyr treatments. In general, the values for the leaf gas exchange parameters net carbon assimilation rate (A), stomatal conductance to water vapour (gs), internal CO2 concentration (Ci) and transpiration rate (E) increased for the infected plants sprayed with ASM or Epo+Pyr in comparison with plants from the control treatment. The values for the initial fluorescence (Fo), maximal fluorescence (Fm), maximal photosystem II quantum efficiency (Fv/Fm), effective photosystem II quantum yield (Y(II)) and quantum yield of regulated energy dissipation (Y(NPQ)) were consistently higher for the ASM and Epo+Pyr treatments in comparison with the control treatment at advanced stages of fungal infection. By contrast, the values for quantum yield of non‐regulated energy dissipation (Y(NO) were significantly lower for the ASM and Epo+Pyr treatments. The concentrations of total Chl a+b and carotenoids significantly increased for infected plants sprayed with ASM and Epo+Pyr in comparison with plants from the control treatment. The results of this study demonstrated that the spray of soybean plants with either ASM or Epo+Pyr contributed to reduce the negative effect of ASR on the photosynthesis of soybean plants. 相似文献
17.
Xuanze Zhang Ying‐Ping Wang Shushi Peng Peter J. Rayner Philippe Ciais Jeremy D. Silver Shilong Piao Zaichun Zhu Xingjie Lu Xiaogu Zheng 《Global Change Biology》2018,24(9):3954-3968
Net biome productivity (NBP) dominates the observed large variation of atmospheric CO2 annual increase over the last five decades. However, the dominant regions controlling inter‐annual to multi‐decadal variability of global NBP are still controversial (semi‐arid regions vs. temperate or tropical forests). By developing a theory for partitioning the variance of NBP into the contributions of net primary production (NPP) and heterotrophic respiration (Rh) at different timescales, and using both observation‐based atmospheric CO2 inversion product and the outputs of 10 process‐based terrestrial ecosystem models forced by 110‐year observational climate, we tried to reconcile the controversy by showing that semi‐arid lands dominate the variability of global NBP at inter‐annual (<10 years) and tropical forests dominate at multi‐decadal scales (>30 years). Results further indicate that global NBP variability is dominated by the NPP component at inter‐annual timescales, and is progressively controlled by Rh with increasing timescale. Multi‐decadal NBP variations of tropical rainforests are modulated by the Pacific Decadal Oscillation (PDO) through its significant influences on both temperature and precipitation. This study calls for long‐term observations for the decadal or longer fluctuations in carbon fluxes to gain insights on the future evolution of global NBP, particularly in the tropical forests that dominate the decadal variability of land carbon uptake and are more effective for climate mitigation. 相似文献
18.
Babu Valliyodan Steven B. Cannon Philipp E. Bayer Shengqiang Shu Anne V. Brown Longhui Ren Jerry Jenkins Claire Y.‐L. Chung Ting‐Fung Chan Christopher G. Daum Christopher Plott Alex Hastie Kobi Baruch Kerrie W. Barry Wei Huang Gunvant Patil Rajeev K. Varshney Haifei Hu Jacqueline Batley Yuxuan Yuan Qijian Song Robert M. Stupar David M. Goodstein Gary Stacey Hon‐Ming Lam Scott A. Jackson Jeremy Schmutz Jane Grimwood David Edwards Henry T. Nguyen 《The Plant journal : for cell and molecular biology》2019,100(5):1066-1082
We report reference‐quality genome assemblies and annotations for two accessions of soybean (Glycine max) and for one accession of Glycine soja, the closest wild relative of G. max. The G. max assemblies provided are for widely used US cultivars: the northern line Williams 82 (Wm82) and the southern line Lee. The Wm82 assembly improves the prior published assembly, and the Lee and G. soja assemblies are new for these accessions. Comparisons among the three accessions show generally high structural conservation, but nucleotide difference of 1.7 single‐nucleotide polymorphisms (snps) per kb between Wm82 and Lee, and 4.7 snps per kb between these lines and G. soja. snp distributions and comparisons with genotypes of the Lee and Wm82 parents highlight patterns of introgression and haplotype structure. Comparisons against the US germplasm collection show placement of the sequenced accessions relative to global soybean diversity. Analysis of a pan‐gene collection shows generally high conservation, with variation occurring primarily in genomically clustered gene families. We found approximately 40–42 inversions per chromosome between either Lee or Wm82v4 and G. soja, and approximately 32 inversions per chromosome between Wm82 and Lee. We also investigated five domestication loci. For each locus, we found two different alleles with functional differences between G. soja and the two domesticated accessions. The genome assemblies for multiple cultivated accessions and for the closest wild ancestor of soybean provides a valuable set of resources for identifying causal variants that underlie traits for the domestication and improvement of soybean, serving as a basis for future research and crop improvement efforts for this important crop species. 相似文献
19.
Sumit Ghosh Mohammad Irfan Niranjan Chakraborty Subhra Chakraborty Asis Datta 《Plant biotechnology journal》2016,14(6):1394-1405
Soya bean (Glycine max) and grass pea (Lathyrus sativus) seeds are important sources of dietary proteins; however, they also contain antinutritional metabolite oxalic acid (OA). Excess dietary intake of OA leads to nephrolithiasis due to the formation of calcium oxalate crystals in kidneys. Besides, OA is also a known precursor of β‐N‐oxalyl‐L ‐α,β‐diaminopropionic acid (β‐ODAP), a neurotoxin found in grass pea. Here, we report the reduction in OA level in soya bean (up to 73%) and grass pea (up to 75%) seeds by constitutive and/or seed‐specific expression of an oxalate‐degrading enzyme, oxalate decarboxylase (FvOXDC) of Flammulina velutipes. In addition, β‐ODAP level of grass pea seeds was also reduced up to 73%. Reduced OA content was interrelated with the associated increase in seeds micronutrients such as calcium, iron and zinc. Moreover, constitutive expression of FvOXDC led to improved tolerance to the fungal pathogen Sclerotinia sclerotiorum that requires OA during host colonization. Importantly, FvOXDC‐expressing soya bean and grass pea plants were similar to the wild type with respect to the morphology and photosynthetic rates, and seed protein pool remained unaltered as revealed by the comparative proteomic analysis. Taken together, these results demonstrated improved seed quality and tolerance to the fungal pathogen in two important legume crops, by the expression of an oxalate‐degrading enzyme. 相似文献
20.
Kelly Juliane Telles Nascimento Daniel Debona Patrícia Ricardino Silveira Leandro Castro Silva Fabio Murilo DaMatta Fabricio Ávila Rodrigues 《Journal of Phytopathology》2016,164(10):768-778
Frogeye leaf spot (FLS), caused by the fungus Cercospora sojina, is one of the most important soybean diseases and can cause great yield losses. Several studies have demonstrated that silicon (Si) enhances the plant antioxidant system, especially when they are subjected to stresses. Thus, this study was designed to evaluate the effect of Si on soybean resistance to FLS, on the antioxidant system, on the concentration of reactive oxygen species and on cellular damage during the infection process of C. sojina. Plants from cultivars Bossier and Conquista, susceptible and resistant to FLS, respectively, were supplied with either 0 (?Si) or 2 mm (+Si) and non‐inoculated or inoculated with C. sojina. FLS severity was greater for Bossier than for Conquista, regardless of the Si supply, and it was increased by Si for both cultivars. The activities of the most antioxidant enzymes were lower in the +Si plants than in the ?Si plants when they were not inoculated. Inoculated plants usually showed an increased enzyme activities and higher concentrations of ascorbate and reduced glutathione than did the non‐inoculated plants, regardless of Si supply. At advanced stages of fungal infection, the +Si‐inoculated plants from Bossier had higher activity of most antioxidant enzymes and higher concentrations of superoxide and malondialdehyde compared to the non‐inoculated plants as a result of an increased oxidative stress. The results from this study provide the first evidence that Si reduces the basal activity of antioxidant enzymes in soybean leaves leading to an increase in host susceptibility to FLS. 相似文献