Plant Carbon Research Articles

Functionalized cross-linking mechanism of biochar “adsorption-reaction microunit” on the promotion of new ammonia-based CO2 capture

Ammonia-based CO2 capture technology has crucial impacts on power plants carbon emission reduction, which has become one of the most concerning issues. However, there are limitations faced by traditional capture technology in the absorption rate, ammonia escape and regeneration energy consumption. The functionalized biochar (with a specific surface area of up to 2835.36 m2/g, micropores volume of 77.4 %) was used to enhance the mass transfer process of new ammonia-based (ammonia-ethanol mixed absorbent) CO2 capture by the bubbling absorption experiment system, combined with Monte Carlo simulations, which explored the adsorption and release characteristics of CO2/NH3 molecules in biochar with different pore sizes. The results show that the CO2 absorption flux added biochar RH-900 is 59.67 L·min, increased by 16.16 % compared with pure absorbent. And the volume mass transfer coefficient is 1.226 × 10-4mol/m2·s·Pa, increased by 15.3 % compared with the SiO2. The addition of RH-900 also promotes the CO2 load capacity of the carbonated solution up to 0.5255 mol/L, enhancing the CO2 absorption capacity and CO2 capture efficiency significantly. The ultra-micropores adsorb CO2, while the surface of larger pores distributes and achieves the adequate fixation of NH3. Besides, the mesopores and macropores provide space where the CO2 is transported and diffused, and the free ammonia concentration is maintained. The study provides an innovative thought for improving the ammonia-based CO2 capture method and significantly reducing of harmful carbon emissions by biomass energy-carbon capture and storage (BECCS) technology.

Ecosystem-dependent responses of soil carbon storage to phosphorus enrichment.

Phosphorus deposition can stimulate both plant carbon inputs and microbial carbon outputs. However, how P enrichment affects soil organic carbon (SOC) storage and the underlying mechanisms remain unclear. We conducted a meta-analysis of 642 SOC observations from 213 field P-addition experiments worldwide, and explored the regulations of plant inputs, microbial outputs, plant characteristics, and environmental and experimental factors on SOC responses. We found that, globally, P addition stimulated SOC by 4.0% (95% CI: 2.0-6.0%), but the stimulation only occurred in forest and cropland rather than in grassland. Across sites, the response of SOC correlated with that of plant aboveground rather than belowground biomass, suggesting that the change in plant inputs from aboveground was more important than that from belowground in regulating SOC changes due to P addition. Among multiple factors, plant N fixation status and mean annual temperature were the best predictors for SOC responses to P addition, with SOC stimulation being higher in ecosystems dominated by symbiotic nitrogen fixers and ecosystems in high-temperature regions like tropical forests. Our findings highlight the differential and ecosystem-dependent responses of SOC to P enrichment, and can contribute to accurate predictions of soil carbon dynamics in a P-enriched world.

Global Change Factors Influence Plant-Epichloë Associations.

There is an increasing interest in determining the influence of global change on plant-microorganism interactions. We review the results of experiments that evaluated the effects of the global change factors carbon dioxide, ozone, temperature, drought, flooding, and salinity on plant symbioses with beneficial Epichloë endophytes. The factors affected the performance of both plants and endophytes as well as the frequency of plants symbiotic with the fungus. Elevated carbon dioxide levels and low temperatures differentially influenced the growth of plants and endophytes, which could compromise the symbioses. Furthermore, we summarise the plant stage in which the effects of the factors were quantified (vegetative, reproductive, or progeny). The factors ozone and drought were studied at all plant stages, but flooding and carbon dioxide were studied in just a few of them. While only studied in response to ozone and drought, evidence showed that the effects of these factors on symbiotic plants persisted trans-generationally. We also identified the putative mechanisms that would explain the effects of the factors on plant-endophyte associations. These mechanisms included the increased contents of reactive oxygen species and defence-related phytohormones, reduced photosynthesis, and altered levels of plant primary metabolites. Finally, we describe the counteracting mechanisms by which endophytes would mitigate the detrimental effects of the factors on plants. In presence of the factors, endophytes increased the contents of antioxidants, reduced the levels of defence-related phytohormones, and enhanced the plant uptake of nutrients and photosynthesis levels. Knowledge gaps regarding the effects of global change on plant-endophyte associations were identified and discussed.

Self-assembled thiophanate-methyl/star polycation complex prevents plant cell-wall penetration and fungal carbon utilization during cotton infection by Verticillium dahliae

No effective fungicides are available for the management of Verticillium dahliae, which causes vascular wilt disease. In this study, a star polycation (SPc)-based nanodelivery system was used for the first time to develop a thiophanate-methyl (TM) nanoagent for the management of V. dahliae. SPc spontaneously assembled with TM through hydrogen bonding and Van der Waals forces to decrease the particle size of TM from 834 to 86 nm. Compared to TM alone, the SPc-loaded TM further reduced the colony diameter of V. dahliae to 1.12 and 0.64 cm, and the spore number to 1.13 × 108 and 0.72 × 108 cfu/mL at the concentrations of 3.77 and 4.71 mg/L, respectively. The TM nanoagents disturbed the expression of various crucial genes in V. dahliae, and contributed to preventing plant cell-wall degradation and carbon utilization by V. dahliae, which mainly impaired the infective interaction between pathogens and plants. TM nanoagents remarkably decreased the plant disease index and the fungal biomass in the root compared to TM alone, and its control efficacy was the best (61.20 %) among the various formulations tested in the field. Furthermore, SPc showed negligible acute toxicity toward cotton seeds. To the best of our knowledge, this study is the first to design a self-assembled nanofungicide that efficiently inhibits V. dahliae growth and protects cotton from the destructive Verticillium wilt.

Inhibition of invasive plant Mikania micrantha rapid growth by host-specific rust (Puccinia spegazzinii).

Mikania micrantha Kunth is a fast-growing global invasive weed species that causes severe damage to natural ecosystems and very large economic losses of forest and crop production. Although Puccinia spegazzinii can effectively inhibit the growth of M. micrantha and is used as a biological control strain in many countries, the mechanism of inhibiting the growth in Mikania micrantha is not clear. Here, we used a combination of phenotypic, enzyme activity, transcriptomic and metabolomic approaches to study the response of M. micrantha after infection by P. spegazzinii. In the early stages of rust infection, JA, JA-Ile and SA levels in infected leaves were significantly lower than that in uninfected leaves. In teliospore initial and developed stages of P. spegazzinii, JA and JA-Ile levels substantially increased by more than 6 times, which resulted in a significant decrease in accumulation of defense hormone SA in infected leaves of M. micrantha. The contents of plant growth-promoting hormones were significantly reduced in the infected plants as a result of substantial downregulation of expression of key genes related to hormone biosynthesis. Furthermore, rust infection led to high levels of ROS in chloroplasts and the destruction of chlorophyll structure, which also led to decreased photosynthetic gene expression, net photosynthetic rate, activity of Rubisco and levels of important organic acids in the Calvin cycle. We hypothesised that after P. spegazzinii infection, JA or JA-Ile accumulation not only inhibited SA levels to promote rust infection and development, but also impeded the rapid growth of M. micrantha by affecting plant growth hormones, carbon, and nitrogen metabolic pathways.

Revealing the Inhibition of Tea Cultivar ‘Ziyan’ Root Growth Caused by High Nitrogen Based on Physiological, Metabolite, and Transcriptome Analyses

Nitrogen (N) is a key regulator in the growth of tea plants and the synthesis of amino acids (AAs) and related secondary metabolites, thus affecting the yield and quality of tea leaves. Increased N fertilization significantly improves the yield and quality of tea plants, but applying excess nitrogen wastes resources and causes pollution problems. Herein, we employed morphological, physiological, metabolomic, and RNA-seq methods to study the response of ‘Ziyan’ roots to high N. High N supply induced an increase in arginine (Arg), asparagine (Asn), and glutamine (Gln) in roots and simultaneously decreased sucrose, polyphenols, and caffeine contents. High N reduced the length, volume, number, and activity of the roots by 10.63%, 25.00%, 26.95%, and 14.50%, respectively, which inhibited ‘Ziyan’ root growth, probably by disturbing the regulation of carbon and nitrogen metabolism in the tea plant. According to the Kyoto Encyclopedia of Genes and Genome (KEGG) enrichment analysis, AAs, flavonoids, and flavonol-related pathways were relatively active after supplying high N. In addition, the transcriptome analysis identified NRT1/PTR and GOGAT as key genes, and the transcription factors (e.g., AP2/ERF, MYB, and WRKY) and auxins were actively involved in the high N stress response of ‘Ziyan’ roots. These findings will help us understand the adaptive mechanism of high N supply in tea tree roots and provide a reference for guiding the fertilization of ‘Ziyan’ tea plants.

Trade-offs between passive and trophic rewilding for biodiversity and ecosystem functioning

Trophic rewilding that reintroduces large animals into landscapes to re-establish food web interactions and restore biodiverse ecosystems has gained widespread attention. Despite this attention, few empirical studies have assessed the effectiveness of trophic rewilding for promoting biodiversity and its wider ecological benefits. Here we tested if trophic rewilding that introduced functional analogues for extinct large herbivores into former farmland of lowland England delivered additional benefits to biodiversity and ecosystems functioning. We predicted that these benefits would exceed those achieved through passive rewilding, that is, unassisted habitat succession after the cessation of agricultural activity. Using a 9-year exclosure experiment, we found trophic rewilding reduced woody plant diversity and total carbon storage by 73% and 23%, respectively, compared to passive rewilding plots that excluded mammalian herbivores. However, trophic rewilding likely increased plant diversity and carbon storage compared to if land was left under continued agricultural production, e.g. artificial pastures associated with intensive livestock production. The vegetation changes accompanying trophic rewilding were further linked to a greater diversity and biomass of ground-dwelling arthropods by 21% and 167%, respectively, relative to passive rewilding, partly by creating more structurally complex vegetation. Given the trade-offs in biodiversity and ecosystem functions between trophic and passive rewilding, our study highlights that trophic rewilding will need to be applied alongside other interventions to tackle biodiversity loss while combatting climate change. Ultimately, the utility of trophic rewilding as a restoration tool will depend on the conservation outcomes valued by society.

Precipitation frequency controls nitrogenous aerosol in a tropical coastal city and its implications for plant carbon sequestration

The concentration of nitrogenous aerosols is influenced by air mass transition, local meteorological conditions, local emissions, and the wet removal effect driven by precipitation. Deposited nitrogenous aerosols influence nitrogen availability in the canopy, affecting the amount of plant carbon sequestration. However, the factors controlling nitrogenous aerosol concentrations and their implications for plant carbon sequestration remain unclear. In this study, multiple stable nitrogen isotopes in atmospheric aerosols (δ15N-TN, δ15N–NO3–, and δ15N–NH4+) and rainwater (rainwater δ15N–NO3– and rainwater δ15N–NH4+) in one-year observations were analyzed to explore the main factors controlling nitrogenous aerosol concentrations. The results showed that NO3− and NH4+ were the major components of TN, and their concentrations in seasonal patterns were sensitive to frequent rainfall rather than local emissions or external contributions. The concentrations of nitrogenous aerosols were negatively correlated with precipitation frequency, indicating that increased precipitation frequency induced low concentrations of nitrogenous aerosols. Moreover, the positive matrix factorization (PMF) analysis showed that coarse mode NO3− was generated in the wet season but not in the dry season, reflecting the removal of precipitation. With the increased precipitation frequency from May to July, 42.4% of aerosol NO3− was scavenged into rainwater, indicated by the variations in the δ15N values of nitrogenous aerosols and rainwater. This result prompted us to calculate the loss of 12.1 ± 3.9 Gg carbon/yr plant carbon sequestration. Our study suggests that nitrogenous aerosols are captured by the high precipitation frequency in tropical areas, decreasing nitrogen availability in the canopy, which might decrease plant carbon sequestration.

Allometry of bud dynamic pattern and linkage between bud traits and ecological stoichiometry of Nitraria tangutorum under fertilizer addition.

Affected by the pressure and constraints of available resources, plant growth and development, as well as plant life history strategies, usually vary with environmental conditions. Plant buds play a crucial role in the life history of woody plants. Nitraria tangutorum is a common dominant woody species in desertified areas of northern China and its growth is critical to the desert ecosystem. Revealing the allometry of N. tangutorum aboveground bud fates and the linkage between bud traits and plant nutrient contents and stoichiometric ratios can be useful in understanding plant adaptation strategy. We applied seven nitrogen and phosphorus fertilizer addition treatments to natural N. tangutorum ramets in Ulan Buh Desert in three consecutive years. We surveyed three types of aboveground buds (dormant buds, vegetative buds, and reproductive buds) in each N. tangutorum ramet, then measured the plant carbon (C), nitrogen (N), and phosphorus (P) contents and ratios during three consecutive years. We specified that reserve growth potential (RGP), vegetative growth intensity (VGI) and sexual reproduction effort (SRE) are the three indices of bud dynamic pattern. The results showed that the bud dynamic pattern of N. tangutorum ramets differed significantly among different fertilizer addition treatments and sampling years. The allometry of RGP, VGI, and SRE was obvious, showing size dependence. The allometric growth relationship fluctuated among the sampling years. The linkage between bud traits and plant stoichiometric characteristics of N. tangutorum ramets showed close correlation with plant P content, C:P and N:P ratios, no significant correlation with plant C content, N content and C:N ratio. These results contribute to an improved understanding of the adaptive strategies of woody plants growing in desert ecosystems and provide insights for adoption of effective measures to restore and conserve plant communities in arid and semi-arid regions.

Optimized Plant Diversity and Carbon Storage for Priority Protection Areas in China

Biodiversity and carbon storage are two key ecosystem functions that are crucial to protect and maintain ecosystem balance. However, there is often little overlap between hotspots for these two different conservation purposes. Additionally, it is not well understood how these different spatial metrics affect these functions in protected ecosystems in China. Here, we explored the relationships between plant diversity metrics and carbon storage by using a large vascular plant distribution dataset, as well as soil fragile organic carbon and biomass carbon datasets in specific spatial areas across China. We also defined priority protection areas (PPAs) using a conservation prioritization method, where 30% of the study areas displayed the highest combined conservation value in carbon storage and plant species richness (SR), phylogenetic diversity (PD), phylogenetic endemism (PE) and evolutionary distinctness (ED). Our results indicated that the correlations between biodiversity metrics and carbon storage were very weak in spatial relationship. However, by including both of these functions in conservation targets, the PPAs could account for more than 95% of the species and evolutionary diversity (PD, ED), and stored large amounts of carbon. Additionally, we broadly divided the PPAs into win–win, high plant diversity, and high carbon areas based on the overlap of biodiversity and carbon storage hotspots. Altogether, our results highlight the importance of understanding and optimizing conservation efforts for different ecosystem functions in different PPAs. Ultimately, this work establishes an urgent need to expand protection in these areas to support mutual biodiversity and carbon storage beneficial solutions.

Larger diurnal temperature range undermined later autumn leaf senescence with warming in Europe

AbstractAimClimate change regulates autumn leaf senescence date (LSD), exhibiting a strong phenological control of plant carbon uptake. Unlike the delaying effect of daily mean temperature (Tmean) on LSD, the impact of warming asymmetry in daytime and nighttime, as evidenced by variations of the diurnal temperature range (DTR), remains elusive. The objectives of this study were to investigate physiological and ecological impacts of DTR on LSD using long‐term in situ observations and to predict the future trends of LSD under warming.LocationEurope.Time period1950–2015.Major taxa studiedPlant phenology.MethodsWe used partial correlation analysis, multiple linear regression and ridge regression to explore the impacts of DTR on LSD. To quantify the importance of potential drivers of LSD, we trained random forest models and applied the SHapley Additive exPlanations method to isolate the marginal contributions of each predictor on LSD. For LSD modelling and projection, we first evaluated two temperature‐driven LSD models [i.e., cooling‐degree‐day (CDD, without DTR effect) and day–night‐temperature CDD (DNCDD, with DTR effect)], then applied them to predict future LSDs.ResultsWe found that observational increases in Tmean and DTR had contrasting effects on LSD. Increased Tmean delayed the LSD, whereas larger DTR overall had an advancing effect. Considering the DTR effect, the Tmean sensitivity of LSD was 14% lower than presently estimated (2.4 vs. 2.8 days °C−1). Warming asymmetry‐related drought stress and plant functional traits (i.e., plant isohydricity and water‐use efficiency) potentially explained the advancing effect of DTR on LSD. We found that current projections of future LSD are overestimated because the DTR effect is discounted, suggesting the need for an adequate understanding of how plant phenology responds to warming asymmetry.Main conclusionsOur findings highlight the importance of DTR in controlling LSD variations with an advancing‐dominant effect and call for the improvement of phenology modelling incorporating the DTR effect. Given that DTR showed a globally narrowing trend over the last several decades, more efforts are needed to understand the potential ecological impacts of warming asymmetry and vegetation response to climate change.

Differential effects of forest-floor litter and roots on soil organic carbon formation in a temperate oak forest

Both forest-floor litter and roots are known to be involved in the formation of soil organic carbon (SOC), but it remains elusive how the two contrasting types of plant carbon sources would differentiate in their effects on SOC. Here we used field-based soil mesocosms to study the responses of SOC components (i.e. mineral-associated organic C [MAOC], particulate organic C [POC], and dissolved organic C [DOC]) and pathways of production (i.e. plant-derived vs. microbial-derived C compounds) to multi-year treatments of forest-floor litter and roots in a temperate oak forest in central China. After eight years, the concentrations of both POC and MAOC were significantly higher in plots with presence of forest-floor litter than in those exclusive of both forest-floor litter and roots at the soil depth of 0–5 cm; roots predominantly affected POC but not the total SOC. The contributions from the forest-floor litter and roots to total SOC and its components were all non-additive; the plots with co-occurrence of forest-floor litter and roots had 49.7% less total SOC, 36.6% less POC, and 54.7% less MAOC, than the sum of the plots with only forest-floor litter or roots, at the soil depth of 0–5 cm. The concentrations of both lignin phenols and microbial biomass carbon (MBC) were significantly higher in plots with only forest-floor litter than in those exclusive of both forest-floor litter and roots down to a depth of 20 cm, and the plant-derived neutral sugars were significantly higher in plots with only forest-floor litter than in those exclusive of both forest-floor litter and roots at the soil depth of 0–10 cm. In contrast, the concentration of lignin phenols was significantly higher in plots with only roots than in those exclusive of both forest-floor litter and roots below the depth of 5 cm, and the concentrations of MBC and microbial-derived neutral sugars were higher in plots with only roots than in those exclusive of both forest-floor litter and roots at the soil depth of 0–10 cm. The plots with co-occurrence of forest-floor litter and roots had a significantly higher concentration of lignin phenols at all soil depths investigated, as well as higher concentrations of the plant- and microbial-derived neutral sugars and MBC at the soil depth of 0–5 cm, than those exclusive of both forest-floor litter and roots; the effects were all non-additive such that the plots with co-occurrence of forest-floor litter and roots had less plant- and microbial-derived C compounds than the sum of the values between the plots with only forest-floor litter and the plots with only roots. The contributions of amino sugars to SOC did not significantly respond to either the treatments with forest-floor litter and roots or soil depth, albeit variable MBC concentrations. In addition, our results show that the microbial-derived neutral sugars were positively correlated with plant-derived neutral sugars. Findings in this study provide empirical evidence on the primacy of forest-floor litter in SOC pool at the soil depth of 0–5 cm, and demonstrate the differential roles and contributions between forest-floor litter and roots in the pathways of SOC formation and spatial differentiation of carbon compounds.

Global patterns and drivers of leaf photosynthetic capacity: The relative importance of environmental factors and evolutionary history

AbstractAimUnderstanding the considerable variability and drivers of global leaf photosynthetic capacity [indicated by the maximum carboxylation rate standardized to 25°C (Vc,max25)] is an essential step for accurate modelling of terrestrial plant photosynthesis and carbon uptake under climate change. Although current environmental conditions have often been connected with empirical and theoretical models to explain global Vc,max25 variability through acclimatization and adaptation, long‐term evolutionary history has largely been neglected, but might also explicitly play a role in shaping the Vc,max25 variability.LocationGlobal.Time periodContemporary.Major taxa studiedTerrestrial plants.MethodsWe compiled a geographically comprehensive global dataset of Vc,max25 for C3 plants (n = 6917 observations from 2157 species and 425 sites covering all major biomes world‐wide), explored the biogeographical and phylogenetic patterns of Vc,max25, and quantified the relative importance of current environmental factors and evolutionary history in driving global Vc,max25 variability.ResultsWe found that Vc,max25 differed across different biomes, with higher mean values in relatively drier regions, and across different life‐forms, with higher mean values in non‐woody relative to woody plants and in legumes relative to non‐leguminous plants. The values of Vc,max25 displayed a significant phylogenetic signal and diverged in a contrasting manner across phylogenetic groups, with a significant trend along the evolutionary axis towards a higher Vc,max25 in more modern clades. A Bayesian phylogenetic linear mixed model revealed that evolutionary history (indicated by phylogeny and species) explained nearly 3‐fold more of the variation in global Vc,max25 than present‐day environment (53 vs. 18%).Main conclusionsThese findings contribute to a comprehensive assessment of the patterns and drivers of global Vc,max25 variability, highlighting the importance of evolutionary history in driving global Vc,max25 variability, hence terrestrial plant photosynthesis.

Biotic stress-induced changes in root exudation confer plant stress tolerance by altering rhizospheric microbial community.

Every organism on the earth maintains some kind of interaction with its neighbours. As plants are sessile, they sense the varied above-ground and below-ground environmental stimuli and decipher these dialogues to the below-ground microbes and neighbouring plants via root exudates as chemical signals resulting in the modulation of the rhizospheric microbial community. The composition of root exudates depends upon the host genotype, environmental cues, and interaction of plants with other biotic factors. Crosstalk of plants with biotic agents such as herbivores, microbes, and neighbouring plants can change host plant root exudate composition, which may permit either positive or negative interactions to generate a battlefield in the rhizosphere. Compatible microbes utilize the plant carbon sources as their organic nutrients and show robust co-evolutionary changes in changing circumstances. In this review, we have mainly focused on the different biotic factors responsible for the synthesis of alternative root exudate composition leading to the modulation of rhizosphere microbiota. Understanding the stress-induced root exudate composition and resulting change in microbial community can help us to devise strategies in engineering plant microbiomes to enhance plant adaptive capabilities in a stressful environment.

Age-Related Rhizosphere Analysis of Coffea arabica Plants.

The analysis of large-scale sequence data has revealed that plants over time recruit certain microbes that are efficient colonizers of the rhizosphere. This enrichment phenomenon is especially seen in annual crops, but we suggest that there could have been some type of enrichment in perennial crops such as coffee plants. To verify this hypothesis, we performed a metagenomic and chemical analysis in rhizosphere with three different plant ages (young, mature, and old) and cultivated on the same farm. We verified that from mature to old plants, there was a decrease in diversity, particularly Fusarium and Plenodomus, while there was an increase in Aspergillus, Cladosporium, Metarhizium, and Pseudomonas. We also detected that the abundance of anti-microbials and ACC-deaminase grows as plants age, although denitrification and carbon fixation had reduced abundances. In summary, we detected an enrichment in the microbial community, especially in the great increase in the participation of Pseudomonas, passing from 50% of the relative abundance as the plants get older. Such enrichment can occur through the dynamics of nutrients such as magnesium and boron.

RNA‐seq analysis of soybean (Glycine max) responding to Phytophthora sojae

AbstractPhytophthora sojae is a devastating pathogen of soybean [Glycine max (L.) Merr.] that causes Phytophthora root and stem rot (PRR) on soybean plants worldwide. The pathogen leads to evident differentiation of pathogenicity which brings some difficulties to the control of the disease. Soybean germplasm plays an important role in disease resistance to P. sojae. To understand the role of soybean in the pathogen differentiation of P. sojae, transcriptome sequencing and biological information technology were used to analyse the difference in transcriptional level of soybean response to P. sojae infection by two isolates BB8 and BZ9 with different pathogenicity. A total of 1596 differentially expressed genes (DEGs) were screened from the soybean plants treated with the strong pathogenic isolate BB8 and weak pathogenic isolate BZ9, of which 256 were upregulated and 1340 were downregulated in BZ9 treated samples. Gene Ontology analysis revealed that the highly enriched terms annotated in biological processes were metabolic process, cellular process and single‐organism process. Kyoto Encyclopedia of Genes and Genomes pathways were distributed primarily in metabolism, environmental information processing and cellular processes. Photosynthesis‐antenna proteins, photosynthesis, phenylpropanoid biosynthesis, carbon fixation in photosynthetic organisms, plant hormone signal transduction, flavonoid biosynthesis, carbon metabolism and nitrogen metabolism were the most substantial metabolic pathways. Ten candidate DEGs were selected and their expression levels were detected via fluorescence quantitative polymerase chain reaction. The expression trends were basically consistent with the results of RNA‐seq detection, confirming the reliability of RNA‐seq data. Taken together, this was the report on the transcriptome analysis of soybean in response to P. sojae using high‐throughput sequencing. A number of DEGs and pathways were discovered, which provided valuable information for obtaining high‐quality soybean resistance resources.

More extreme and frequent drought periods reduced crop production and altered stable isotope ratios of C and N in plants

Summary Climate change scenarios predict more frequent and intense drought periods for 2071–2100 in the most important and intensively used agricultural region of Austria, the Marchfeld. Current and predicted lower precipitation scenarios were simulated at a lysimeter station for 9 years. Plant biomass, nitrogen (N) and carbon (C) content, and δ13C and δ15N values of plant compartments were monitored in years 7–9. Aboveground biomass of cereals and grain yield decreased under the predicted scenario, while the quality of grain (% N) was unaffected. Weed and catch crops grown in winter were not affected or were even positively affected, possibly due to the accumulation of nutrients in the soil following the lower plant uptake in summer. Accordingly, low plant δ15N values were mainly attributed to the presence of higher proportion of mineral fertilizer in the predicted precipitation scenario. As expected, water stress significantly increased δ13C values in plants grown over summer, while this was not seen for plants growing over winter. Fertile agricultural soil might ameliorate but cannot outbalance the negative impact of more frequent and intense drought periods.

Influence of soil geomorphic factors on vegetation patterns in a model white sands ecosystem complex

Understanding the development of white sands ecosystems (WSEs) and their occurrence is critical for determining structural diversity in global biodiversity hotspots. WSE has fascinated ecologists for decades, with soil always opined to play a critical role in the development of complex ecosystem vegetation patterns. However, few to no studies have systematically investigated the effect of soil natural capital on the complex vegetation patterns in humid tropical forests that include the occurrence of open savannas. Instead, fires have been advanced as the key driver that sustains and expands open savannas in tropical forest biomes. In this study, we investigated the effects of soil geomorphic factors on vegetation patterns that range from tropical forests to open savannas in a model WSE complex known as the Aripo savannas scientific reserve. Soils were sampled from three white sands landscapes, each containing three vegetation types (open savanna, palm island, and marsh forest). Two transects of five soil sampling sites were randomly sampled in each vegetation type where stratified sampling of microtopography (hollows and flats) was applied. Samples were analyzed mainly for chemical properties, with some physical and mineralogical properties. Results showed patterns and relationships amongst vegetation types. Parent material was rich in quartz and zircon, poor in alkalis and sesquioxides, and resistant to weathering, forming white sands. Open savannas were significantly higher (P < 0.05) in coarse silt (32.8 %) and fine sand (34.1 %) and lower in fine silt and clay, suggesting a clear sorting associated with aeolian cover sands. In microtopographic areas, the upward gradient of water potential drove matter accumulation in hollows and upward translocation of elements under flat relief. The plant available nutrients and carbon were significantly lower (P < 0.05) in open savannas, demonstrating that plant nutrition was resource dependent. The Al concentration and pH matched with the vegetation patterns with a significantly decreasing Al concentration from forests (953 ppm) to open savannas (223 ppm) and significantly increasing pH from forests (3.7) to open savanna (4.1). Interestingly, the significantly lower Al concentration and higher pH in the open savanna suggest that these properties though more favorable in this locale, did not support tree growth and therefore were not predominant determinants of vegetation patterns. Quartz dominated all textural fractions, with clay fractions (which increased under forest) having higher levels of non-quartz minerals, e.g., silica. Silica, which is more degradable and initially provided more cations (nutrients and Al) to forest vegetation. Therefore, both texture (clay size) and minerals (clay minerals) together, degraded and delivered more cations. We conclude that WSEs in tropical forests developed on originally poor parent material. Since natural fire regimes are unlikely in this ecosystem, differences in vegetation distribution were not attributable to fires but are related to soil variability due to weathering and pre- weathering sorting. Most likely matter transport by lateral sheet water flow due to soil geomorphology is another factor controlling the development of vegetation patterns within WSE mainly found in humid tropical areas where wet season rainfall exceeds 2000 mm.

Estimation of Carbon pool in various agricultural crops in peatlands of West and Central Kalimantan, Indonesia

Tropical peat is an important natural ecosystem, and its natural state plays an important role in climate regulation. These peatlands globally provide vital environmental benefits, especially in case of their enormous carbon storage potential. Peat land also functions as a source of livelihood for the community, especially for agricultural activities, and this will lead to the potential loss of carbon stock in peatlands. This study examines plants' potential to create Carbon to offset carbon dioxide emissions and different land use types. The study focused on Central and West Kalimantan, Indonesia. Peat soil samples were collected from various types of land from 0-15, 15-45, and 45-100 cm depth and analyzed for physical and chemical parameters. The cylinder chamber method with infrared gas analysis model EGM-4 was used to measure CO2 emissions. Plant carbon sequestration was measured in a 6.25 m2 plot in the study sites of Central Kalimantan. The study showed that type of commodity and period of management affect the carbon content in peat with different land uses, and it is affected by soil bulk density, organic matter content, and CO2 emission. In the case of study crops, oil palm, rubber, corn, and mustard emit the highest CO2. Further, corn crop has the highest potential to fix carbon dioxide and produces more Carbon per hectare than the Carbon emitted from corn-planted under peatland conditions. The study indicated that the type of commodity and the time of its management affected the carbon content in peat with different land uses, and carbon content got the change with soil bulk density and soil organic matter content.

Soil Fungal Community Structure and Its Effect on CO2 Emissions in the Yellow River Delta

Soil salinization is one of the most compelling environmental problems on a global scale. Fungi play a crucial role in promoting plant growth, enhancing salt tolerance, and inducing disease resistance. Moreover, microorganisms decompose organic matter to release carbon dioxide, and soil fungi also use plant carbon as a nutrient and participate in the soil carbon cycle. Therefore, we used high-throughput sequencing technology to explore the characteristics of the structures of soil fungal communities under different salinity gradients and whether the fungal communities influence CO2 emissions in the Yellow River Delta; we then combined this with molecular ecological networks to reveal the mechanisms by which fungi adapt to salt stress. In the Yellow River Delta, a total of 192 fungal genera belonging to eight phyla were identified, with Ascomycota dominating the fungal community. Soil salinity was the dominant factor affecting the number of OTUs, Chao1 index, and ACE index of the fungal communities, with correlation coefficients of -0.66, 0.61, and -0.60, respectively (p < 0.05). Moreover, the fungal richness indices (Chao1 and ACE) and OTUs increased with the increase in soil salinity. Chaetomium, Fusarium, Mortierella, Alternaria, and Malassezia were the dominant fungal groups, leading to the differences in the structures of fungal communities under different salinity gradients. Electrical conductivity, temperature, available phosphorus, available nitrogen, total nitrogen, and clay had a significant impact on the fungal community structure (p < 0.05). Electrical conductivity had the greatest influence and was the dominant factor that led to the difference in the distribution patterns of fungal communities under different salinity gradients (p < 0.05). The node quantity, edge quantity, and modularity coefficients of the networks increased with the salinity gradient. The Ascomycota occupied an important position in the saline soil environment and played a key role in maintaining the stability of the fungal community. Soil salinity decreases soil fungal diversity (estimate: -0.58, p < 0.05), and soil environmental factors also affect CO2 emissions by influencing fungal communities. These results highlight soil salinity as a key environmental factor influencing fungal communities. Furthermore, the significant role of fungi in influencing CO2 cycling in the Yellow River Delta, especially in the environmental context of salinization, should be further investigated in the future.