Plant and Soil最新文献

Background and aims

Brazilian Cerrado soils have low phosphorus content, leading many farmers to frequently apply fertilizers. With respect to this, Trichoderma are fungi with traits that can improve the fertility and health of the soil and promote plant growth. In this study, native strains of Trichoderma (T. viride GT-8, T. reesei GT-31, and T. longibrachiatum GT-32) from the Brazilian Cerrado were characterized. The impact of their inoculation on soybean growth and grain yield was also assessed under two phosphate fertilization conditions: 400 and 200 kg ha⁻¹ of simple superphosphate (SPP). Two independent field experiments were conducted with the cultivars Nidera NS6601 IPRO and DM 69IX60RSF 12X RR2PRO. Leaf and rhizospheric soil samples were collected for biochemical analyses.

Results

The strains showed phosphate solubilization from fertilizers and exhibited other PGP traits. Inoculation of GT-32 on cv. Nidera NS6601 resulted in a 4.5% increase in grain yield under 200 kg ha⁻¹ of SPP. For the second cultivar, the use of GT-31 and GT-32 at 200 kg ha⁻¹ of SSP resulted in grain yield increases of 22.7% and 18.6%, respectively. Inoculated plants showed higher shoot dry weight, chlorophyll content, phenolic compounds, and antioxidant responses under both fertilization conditions. Furthermore, enzymatic activities were higher in the rhizospheric soil of plants inoculated with GT-31 and GT-32 strains.

Conclusion

These findings demonstrated the potential of the GT-31 and GT-32 strains to improve soybean growth and yield with reduced fertilizer use. Additionally, their use could offer a sustainable strategy for enhancing soil health and fertility in Brazilian Cerrado soils.

Graphical Abstract

Background and aims

Exchangeable aluminum (Al) released from acidic soil (pH < 5.5) inhibits root elongation and reduces crop yield. This study aimed to explore the possible mechanism of soybean response to Al toxicity stress.

Methods

An integrated analysis of transcriptome and metabolome was applied to compare Al-tolerant (NN99-6) and Al-sensitive (ZD32) soybean germplasms in response to Al toxicity.

Results

The root growth of NN99-6 genotype was less inhibited under Al toxicity compared to ZD32 genotype. Following a three-day Al toxicity treatment, both the relative primary root elongation and relative total root length were greater in NN99-6 than in ZD32. Transcriptome analysis identified 2555 differentially expressed genes (DEGs) in NN99-6 and 2577 DEGs in ZD32, respectively. 140 differentially expressed metabolites (DEMs) in NN99-6 and 161 DEMs in ZD32 were respectively detected by metabolome analysis. Based on the integrated transcriptome and metabolome analysis, DEGs and DEMs were primarily enriched in lignin and aldarate biosynthesis, isoflavonoid biosynthesis, ASA-GSH and SAM cycle. Compared to ZD32, most DEGs and DEMs were mainly up-regulated in NN99-6. The proposed model showed that the high expression level of DEGs and DEMs in enriched pathways may benefit the synthesis and repair of the cell wall and improve the antoxidation in NN99-6, ultimately alleviating Al toxicity.

Conclusion

This study offers an effective strategy to explore DEGs and DEMs in response to Al toxicity, clarifying the mechanism of Al toxicity resistance by improving the synthesis and repair of cell wall and antoxidation in soybean.

Backgrounds and Aims

Forest litter is mainly composed by leaves, roots and wood debris (WD) residues. WD decomposition in Mediterranean ecosystems has received less attention compared to other materials and to boreal, tropical and temperate biomes. The OMDY model describes organic matter decomposition using ¹³C NMR spectroscopy.

Methods

The mass loss and the ¹³C NMR of ten mediterranean wood and shrub species were monitored for a long-term (5 years) experiment. The regularized generalized regression LASSO was used to select the NMR spectra regions more predictable for the WD decomposition. The OMDY model was applied to simulate the long-term decomposition experiment of ten mediterranean wood and shrub species.

Results

WD species, chemical composition and decomposition time significantly influenced the dynamics of the remaining mass during the decomposition. The NMR analysis revealed an increase in alkyl C and carbonyl C while a decrease in di-O-alkyl C and O-alkyl C. Pistacia lentiscus L. showed the highest decomposition, with a O-alkyl C declining and alkyl C rising. Erica arborea L. decomposed less, showing smaller decreases in O-alkyl C, lower alkyl C accumulation. The LASSO method identified three chemical regions as crucial for WD decomposition. The OMDY model, using as input these NMR molecular regions, demonstrated a high capacity to describe long-term WD decomposition.

Conclusions

The model is adaptable to describe the decomposition of wood. The results show that the model is general, as NMR can describe different materials' spectra and ordinary differential equations predict their reduction.

Aims

White fonio is an ancient West African orphan millet crop. As one of the world’s fastest-maturing cereals, it helps smallholders mitigate mid-season hunger. There are no reported studies on drought acclimation responses in fonio to identify traits that can enable breeding for climate change adaptation.

Methods

Here, two white fonio accessions from wetter (Guinea) and dryer (Mali) environments were grown indoors under three moisture levels in replicated trials. Physiological, morphological and metabolomic phenotyping was undertaken, including root system architecture analysis, culminating in measuring ~ 27,000 root hairs.

Results

Fonio responded to drought by dramatically upregulating glycine- and alanine-betaine leaf concentrations. Both accessions exhibited increased root:shoot ratio and leaf angle, but reduced shoot branching, leaf width, transpiration, and stomatal conductance. Grain yield most positively correlated with SPAD chlorophyll. Lower grain fill was observed in the Guinea accession, while the Mali accession showed a surprising increase in the harvest index when exposed to extreme drought. In the Mali accession, drought resulted in fewer but longer crown roots, increased lateral root branching, and a greater density and lengthening of root hairs. In particular, leaf width, angle and SPAD were identified as cost- and time effective selection traits.

Conclusions

This paper has identified above- and below-ground drought acclimation traits in white fonio. These results build a foundation for future efforts to breed this crop to tolerate accelerating climate change, ultimately to assist vulnerable West African farmers.

Background and aims

Chinese-fir (Cunninghamia lanceolata) clonal varieties are used to establish fast-growing plantations in subtropical China and produce litters of varying quality. Litter serves as primary sources of carbon (C) and nitrogen (N) inputs to soils in forests and plays an important role in regulating soil N transformations, including N losses via nitrous oxide (N₂O) emissions. However, little is known about the effects of litter addition from different Chinese-fir clones on soil N dynamics.

Methods

We conducted an aerobic incubation experiment to investigate net rates of N mineralization (NMR) and nitrification (NNR) and N₂O emissions in soils from seven forests planted with different Chinese-fir clones as affected by litter addition at the rates of 0, 0.3%, 0.6%, and 0.9% of dry soil weight.

Results

Both NMR and NNR decreased linearly with increasing litter addition rate, while soil respiration and N₂O emissions exhibited the opposite, regardless of the clonal treatment. In addition, NMR and NNR, expressed as mg N per g carbon (C) applied, either decreased or increased logarithmically with increasing soil pH and C to phosphorus (P) ratio, respectively. Structural equation modeling showed that litter properties (i.e., C/N and total P content) drive NMR and NNR by influencing soil respiration, pH, and nutrient stoichiometry. However, the response of N₂O emissions to litter addition is not associated with either soil or litter properties.

Conclusions

Our findings indicate that effects of adding litter from Chinese-fir clones on soil N transformations are dependent on edaphic factors, which are primarily influenced by litter quality.

Background and aims

There is a risk of high concentration cadmium pollution in farmland near heavy industrial activity areas. The combination of arbuscular mycorrhizal fungus (AMF) and hyperaccumulators is a suitable means of remediation. However, the effect of combination on soil biogeochemistry are often overlooked.

Methods

Therefore, we used pot experiments to explore the effects of combined treatments on soil microbial diversity and the driving factors of changes under high Cd pollution.

Result

Results showed that the synergy between Rhizophagus intraradices and Solanum nigrum promoted retention in the root of S. nigrum and diminished the Cd bioavailability in the soil. Furthermore, R. intraradices inoculation successfully rehabilitated the bacterial network adversely affected by Cd contamination, augmenting bacterial α-diversity. R. intraradices effectively mitigates survival pressures on Subgroup_6, 67-14, RB41, and key bacterial genus. Moreover, R. intraradices inoculation led to a significant upswing in soil phosphatase (24.47%) and catalase (34.70%) activities. Additionally, this inoculation engendered heightened nutrient levels and a reduction in soil pH.

Conclusion

Collectively, our study underscores the efficacy of combining R. intraradices with S. nigrum as an strategy for diminishing high Cd pollution in soil while concurrently improving soil health.

Aims

Straw return represents an effective measure for the improvement of saline soil. In order to address the deficiencies of conventional long-strip straw interlayer and straw topsoil mixing, as well as to leverage the regulation of salt stress resistance in plants, this study devised an innovative straw return method that combined powder straw interlayer and topsoil mixing. The objective of this method was to reduce soil salinity, improve soil structure, and promote plant growth.

Methods

A tomato pot experiment was conducted to compare the effects of different straw lengths (S₅₀: 50 mm, S₁₀: 10 mm, S₂: 2 mm) and burial modes (W_i: interlayer, W_m: topsoil mixing, W_im: interlayer and topsoil mixing) on the soil physicochemical properties, tomato root biochemical indexes, fruit yield and dry matter weight of above-ground.

Results

The study found that: (1) Straw burial mode exerted a more pronounced impact than straw length on the salt distribution of soil. (2) The S₅₀W_im, S₁₀W_im, and S₂W_im treatments exhibited more significant differences on the non-uniform distribution of salt, thereby promoting the regulation of tomato roots to salt stress and effectively mitigating its adverse effects. (3) The S₂W_im treatment can significantly improve tomato fruit yield and dry matter weight of above-ground.

Conclusion

It was concluded that the straw return method that combined 2 mm powder straw interlayer and topsoil mixing (S₂W_im) can effectively optimize the salt distribution of soil, promote the regulation of tomato to salt stress, alleviate the adverse effects of salt stress, and ultimately improve tomato fruit yield.

Background and Aims

Mountain ecosystems are highly vulnerable to global changes. Soil biodiversity is critical for maintaining ecosystem multifunctionality, yet the contribution of soil invertebrate diversity in supporting multifunctionality in mountain ecosystems is poorly understood.

Methods

Here, we assessed the contribution of soil invertebrate diversity, including α-diversity (i.e., species richness) and β-diversity (i.e., community composition), in explaining multiple ecosystem functions (e.g., water regulation, soil carbon stocks, nutrient cycling, organic matter decomposition, and pathogen control) along two independent elevation gradients of the Tibetan Plateau and Shennongjia Mountain in China.

Results

Our results showed that ecosystem multifunctionality gradually increased with increasing elevation. Significant linear relationships were observed between species richness and community composition of soil invertebrates and multifunctionality along the elevation gradients, with species richness explaining more variance in multifunctionality than community composition. Furthermore, the positive associations between soil invertebrate richness and ecosystem multifunctionality remained consistent and robust along the two elevation gradients after considering climate and soil environmental variables. Structural equation modeling further revealed that the relationships between soil invertebrate diversity and ecosystem multifunctionality were primarily linked to elevation-induced variations in soil properties such as C/N ratio and pH.

Conclusion

Our work highlights that the variation in soil invertebrate diversity along elevation gradients plays a critical role in supporting the multifunctionality of mountain ecosystems.

Context

Phenotypic plasticity can be a valuable adaptation strategy for coping with environmental heterogeneity. There is limited information on the plasticity of root traits and their effect on yield and yield stability.

Objectives

With a perspective of phenotypic plasticity, we focus on functional root traits associated to water uptake in field-grown sorghum to answer: (i) How do genetic (G), environmental (E) and management (M) factors and their interactions, affect the root traits? and (ii) How do root traits and their plasticity affect yield and yield stability?

Methods

A new high-throughput functional root phenotyping approach was used in G × E × M trials to quantify two root traits, maximum rooting depth (MxRD) and a root activity index (RAindex). Crop phenotypic plasticities were determined using the reaction norm method.

Results

The applied G × E × M treatments created plastic responses between the tested hybrids. There was a hierarchy of plasticities for the different traits studied i.e., grain number traits > root traits > grain weight traits. The plasticity of root traits was associated with the stability of grain yield traits. Hybrids with high root plasticity tend to have more stable grain numbers and grain weights.

Conclusions

There is valuable genetic diversity in the mean value and plasticity of root traits that could be used to match root phenotypes to target production environments. Our root phenotyping approach can be a valuable tool for understanding the dynamic interactions between root function, root architecture and yield traits in the field under variable environments. 

Background and aims

Promoting soil organic carbon (SOC) sequestration is the key to improving soil quality. Adding organic materials is a common practice to promote SOC sequestration. However, the mechanism of SOC sequestration in saline-alkali soil with different organic materials addition is still unclear.

Methods

Field experiment was conducted: (1) Control, no fertilization; (2) NPK, only mineral fertilizer addition; (3) OF, NPK plus 2000 kg C ha^-1 addition of organic fertilizer; (4) MS, NPK plus 2000 kg C ha^-1 addition of maize straw.

Results

Compared with NPK treatment, the mean weight diameter (MWD) in OF and MS treatments was increased by 23.08% and 11.54%, respectively, which was due to the reduction of exchangeable sodium saturation percentage. Exchangeable calcium and magnesium were positively correlated with MWD, and their contents in OF treatment were 6.89-32.05% higher than those in MS treatment. Meanwhile, MWD was positively correlated with SOC stock, and small macro-aggregates contributed the most to SOC. Compared with NPK treatment, the ratio of mineral-associated organic carbon to particular organic carbon in MS and OF treatments were increased by 34.06% and 80.88%, respectively. Exchangeable magnesium and calcium could bind with polysaccharide, carboxyl and phenol to form complex under organic materials addition. Hence, SOC stock in OF and MS treatments was increased by 14.18% and 6.38% compared to NPK treatment, respectively.

Conclusion

The addition of organic materials improved the stability of aggregate structure and SOC pool in saline-alkali soil, thereby promoting SOC sequestration, in which organic fertilizer showed better effect.

Graphical Abstract