Wheat genotypes with higher yield sensitivity to drought overproduced proline and lost minor biomass under severer water stress.

To clarify the differences in growth and yield responses to drought stress among genotypes contrasting in environmental background, dryland and irrigated genotypes, as well as the underlying biochemical mechanism would provide valuable information for developing superior dryland cultivars. Pot experiments for the whole life cycle in fifteen genotypes and comparative metabolomics analysis for seedlings between two drought tolerant (DT) dryland genotypes and two drought sensitive (DS) irrigated ones were carried out. The DT dryland genotypes suffered heavy biomass loss during severer drought but showed minor yield loss ultimately, while the DS irrigated ones showed minor biomass loss but greater yield loss.

Mapping Chinese annual gross primary productivity with eddy covariance measurements and machine learning.

Annual gross primary productivity (AGPP) is the basis for grain production and terrestrial carbon sequestration. Mapping regional AGPP from site measurements provides methodological support for analysing AGPP spatiotemporal variations thereby ensures regional food security and mitigates climate change. Based on 641 site-year eddy covariance measuring AGPP from China, we built an AGPP mapping scheme based on its formation and selected the optimal mapping way, which was conducted through analysing the predicting performances of divergent mapping tools, variable combinations, and mapping approaches in predicting observed AGPP variations.

Climate-induced increase in terrestrial carbon storage in the Yangtze River Economic Belt.

Predicting the change in carbon storage in regions of high carbon uptake and those under highly intensive human disturbance is crucial for regional ecosystem management to promote sustainable development of the economy and ecology in the future. We use a process-based model to estimate the terrestrial carbon storage in Yangtze River Economic Belt (YREB) and to predict the change of carbon storage over the next 100 years. The results show that the vegetation carbon (VC) and soil organic carbon (SOC) storage were 8.

Spatial-temporal variations of carbon storage and carbon sequestration rate in China's national forest parks.

Forests play an important role in regulating climate change and maintaining carbon balance. To explore the carbon storage and carbon sequestration rate of national forest parks is of great significance for carbon sequestration capacity assessment and sustainable forest management. A process-based ecosystem model (CEVSA2 model) was used to simulate the spatial distribution of carbon density, carbon storage and carbon sequestration rate of 881 national forest parks in China during 1982-2017.

Stomatal conductance bears no correlation with transpiration rate in wheat during their diurnal variation under high air humidity.

A good understanding of the response of photosynthesis rate ( ) and transpiration rate () to stomatal alteration during the diurnal variations is important to cumulative photosynthetic production and water loss of crops. Six wheat genotypes were studied for 2 years with pot cultivation in rain-shelter. Among different genotypes, stomatal conductance ( ) was significantly correlated with both and .

Dynamic changes in membrane lipid composition of leaves of winter wheat seedlings in response to PEG-induced water stress.

Background: Membrane lipid composition associates closely with membrane stability and fluidity under water stress. In this study, lipidomic analyses based on electrospray ionization mass spectrometry (ESI-MS/MS) were carried out to explore dynamic changes of membrane lipids in term of molecular species caused by PEG (Polyethylene glycol-6000)-induced water stress in wheat seedlings.

Results: Among the main phospholipids, phosphatidylcholine (PC), phosphatidylethanolamine (PE), and phosphatidylglycerol (PG) are primary degradation targets, and PC was degraded in the largest degree.

Effect of simulated warming on the functional traits of plant in Songnen grassland.

grassland in Northeast China provides a natural laboratory for the investigation of climate change. The response of to experimental warming can provide insight into its regeneration behaviour and the likely composition of future communities under warmer climate. We used MSR-2420 infrared radiators to elevate temperature and examined soil organic carbon and nitrogen and soil total phosphorus and determined the growth and physiology of in response to manipulations of ambient condition and warming.

Discrepancies in vegetation phenology trends and shift patterns in different climatic zones in middle and eastern Eurasia between 1982 and 2015.

Changes in vegetation phenology directly reflect the response of vegetation growth to climate change. In this study, using the Normalized Difference Vegetation Index dataset from 1982 to 2015, we extracted start date of vegetation growing season (SOS), end date of vegetation growing season (EOS), and length of vegetation growing season (LOS) in the middle and eastern Eurasia region and evaluated linear trends in SOS, EOS, and LOS for the entire study area, as well as for four climatic zones. The results show that the LOS has significantly increased by 0.

iTRAQ protein profile analysis of young and old leaves of cotton (Gossypium hirsutum L.) differing in response to alkali stress.

Proteins will provide a new perspective and deeper understanding for the research of crop alkali tolerance. The aims of this study were to determine and identify the differentially abundant proteins and adaptive mechanisms to alkali tolerance between young and old leaves of cotton. The 4704 proteins were identified, in which 1490 were significantly changed in young leaves and 563 were changed in old leaves in response to alkali stress.

iTRAQ-Based Quantitative Analysis of Responsive Proteins Under PEG-Induced Drought Stress in Wheat Leaves.

Drought is an important abiotic stress that seriously restricts crop productivity. An understanding of drought tolerance mechanisms offers guidance for cultivar improvement. In order to understand how a well-known wheat genotype Jinmai 47 responds to drought, we adopted the iTRAQ and LC/MS approaches and conducted proteomics analysis of leaves after exposure to 20% of polyethylene glycol-6000 (PEG)-induced stress for 4 days.

Metabolic response and correlations between ions and metabolites in Phragmites communis under long-term salinity toxicity.

Phragmites communis has a long history in Songnen grassland of China and has a series of biological, ecological as well as genetic characteristics contributing to its adaptation to the specific local climatic and edaphic conditions. The aim of the present study was to investigate the ions balance and their relationship to metabolites in P. communis under three salinity stress conditions.

Global vegetation productivity responses to the West Pacific Warm Pool.

Sea surface temperatures (SSTs) strongly influence atmospheric circulation and the Earth's climate, which in turn significantly affects vegetation productivity. Most of the previous studies on the subject have focused on links between the El Niño-Southern Oscillation (ENSO) and vegetation productivity, but few studies have addressed the effects of West Pacific Warm Pool (WPWP) on that although the early stages of the ENSO phenomenon may first develop there. In this paper, we use the mean SST values in the WPWP to construct a climate index, known as the WPWP index (WPI), and study the impacts of the WPWP on global vegetation productivity.

Tissue physiological metabolic adaptability in young and old leaves of reed (Phragmites communis) in Songnen grassland.

Common reed (Phragmites communis) is widely distributed as the dominant plant species in the Songnen Plain of China. The aim of this study was to investigate different physiological adaptive mechanisms to salinity tolerance between young and old leaves. The profiles of 68 metabolites were measured and studied in reed leaves by gas chromatography-mass spectrometer.

Metabolic responses to drought stress in the tissues of drought-tolerant and drought-sensitive wheat genotype seedlings.

An in-depth understanding of the effects of drought stress on plant metabolism is necessary to improve the drought tolerance of wheat and to utilize genetic resources for the development of drought stress-tolerant wheat varieties. In this study, the profiles of 58 key metabolites produced by wheat seedlings in response to drought stress were investigated to determine various physiological processes related to drought tolerance between drought-tolerant and drought-sensitive wheat genotypes. Results showed that the wheat metabolome was dominated by sugars, organic acids and amino acids; the wheat metabolome played important roles to enhance the drought tolerance of shoots.

Ecosystem respiration and its components in a rainfed spring maize cropland in the Loess Plateau, China.

We estimated ecosystem respiration (Re) and its components in a rainfed spring maize field in the Loess Plateau, China, during the growing seasons of 2012, 2013, and 2014 using measurements of eddy covariance and soil respiration (Rs). The multi-factor equation, which included photosynthetic active radiation, 5-cm soil temperature, 10-cm soil water content, and green leaf area index (GLAI), had goodness-of-fit values of between 0.81 and 0.

Effects of climate warming on net primary productivity in China during 1961-2010.

The response of ecosystems to different magnitudes of climate warming and corresponding precipitation changes during the last few decades may provide an important reference for predicting the magnitude and trajectory of net primary productivity (NPP) in the future. In this study, a process-based ecosystem model, Carbon Exchange between Vegetation, Soil and Atmosphere (CEVSA), was used to investigate the response of NPP to warming at both national and subregional scales during 1961-2010. The results suggest that a 1.

Carbon budget of a rainfed spring maize cropland with straw returning on the Loess Plateau, China.

Assessing the carbon budget of rainfed agricultural ecosystems is a vital component in the process of estimating the global carbon balance. We used eddy covariance techniques combined with soil respiration measurements to estimate the carbon budget of a rainfed spring maize field where straw returning was practiced, on the Loess Plateau, China, during 2012-2014. Carbon fluxes and their components (except heterotrophic respiration, R) exhibited single-peak seasonal patterns, and linear relationships were found between daily gross primary productivity (GPP) and net ecosystem exchange (NEE), and between daily GPP and ecosystem respiration (R), with goodness of fit value of 0.

Ionomic and metabolic responses to neutral salt or alkaline salt stresses in maize (Zea mays L.) seedlings.

Background: Soil salinity and alkalinity present a serious threat to global agriculture. However, most of the studies have focused on neutral salt stress, and the information on the metabolic responses of plants to alkaline salt stress is limited. This investigation aimed at determining the influence of neutral salt and alkaline salt stresses on the content of metal elements and metabolites in maize plant tissues, by using mixtures of various proportions of NaCl, NaHCO, NaSO, and NaCO.

[Spatial heterogeneity of vegetation and soil characteristics in oasis-desert ecotone].

The spatial distribution of bio- and abiotic factors in ecosystem has the features of spatial heterogeneity in general, and spatial heterogeneity is important in the function and process of ecosystem at a variety of scales. In this paper, semivariance theory and methods were used to study the degree, composition, scale and pattern of spatial heterogeneity of vegetation coverage and soil environment factors, and their relationships in the Fukang oasis-desert ecotone of Xinjiang. With block kriging in the studied area of sampling, the spatial pattern of each factor was expressed in three dimensions as well.

[Coupling relationship between plant communities' species diversity and soil factors in ecotone between desert and oasis in Fukang, Xinjiang].

Regression analysis was used to study the relationship between four diversity indices and 19 soil factors at three different soil layers in ecotone between desert and oasis in Fukang, Xinjiang. The results indicated that soil pH, total salt content, soil organic matter, Cl-, K+ + Na+, Mg2+, total nitrogen, and available phosphorus were correlative to species diversity significantly (P < 0.05).