Explore the vast range of titles available.

Background Intercropping, a diversified planting pattern, increases land use efficiency and farmland ecological diversity. We explored the changes in soil physicochemical properties, nutrient uptake and utilization, and microbial community composition in wide-strip intercropping of maize and peanut. Results The results from three treatments, sole maize, sole peanut and intercropping of maize and peanut, showed that intercropped maize had a marginal advantage and that the nutrient content of roots, stems and grains in side-row maize was better than that in the middle row of intercropped maize and sole maize. The yield of intercropped maize was higher than that of sole cropping. The interaction between crops significantly increased soil peroxidase activity, and significantly decreased protease and dehydrogenase activities in intercropped maize and intercropped peanut. The diversity and richness of bacteria and fungi decreased in intercropped maize rhizosphere soil, whereas the richness of fungi increased intercropped peanut. RB41 , Candidatus-udaeobacter , Stropharia , Fusarium and Penicillium were positively correlated with soil peroxidase activity, and negatively correlated with soil protease and dehydrogenase activities. In addition, intercropping enriched the functional diversity of the bacterial community and reduced pathogenic fungi. Conclusion Intercropping changed the composition and diversity of the bacterial and fungal communities in rhizosphere soil, enriched beneficial microbes, increased the nitrogen content of intercropped maize and provided a scientific basis for promoting intercropping in northeastern China.

Background Nitrogen (N) is a crucial element for increasing photosynthesis and crop yields. The study aims to evaluate the photosynthetic regulation and yield formation mechanisms of different nodulating peanut varieties with N fertilizer application. Method The present work explored the effect of N fertilizer application rates (N0, N45, N105, and N165) on the photosynthetic characteristics, chlorophyll fluorescence characteristics, dry matter, N accumulation, and yield of four peanut varieties. Results The results showed that N application increased the photosynthetic capacity, dry matter, N accumulation, and yield of peanuts. The measurement of chlorophyll a fluorescence revealed that the K-phase, J-phase, and I-phase from the OJIP curve decreased under N105 treatment compared with N0, and W OI , ET 0 /CS M , RE 0 /CS M , ET 0 /RC, RE 0 /RC, φPo, φEo, φRo, and Ψ0 increased, whereas V J , V I , W K , ABS/RC, TR 0 /RC, DI 0 /RC, and φDo decreased. Meanwhile, the photosystem activity and electron transfer efficiency of nodulating peanut varieties decreased with an increase in N (N165). However, the photosynthetic capacity and yield of the non-nodulating peanut variety, which highly depended on N fertilizer, increased with an increase in N. Conclusion Optimized N application (N105) increased the activity of the photosystem II (PSII) reaction center, improved the electron and energy transfer performance in the photosynthetic electron transport chain, and reduced the energy dissipation of leaves in nodulating peanut varieties, which is conducive to improving the yield. Nevertheless, high N (N165) had a positive effect on the photosystem and yield of non-nodulating peanut. The results provide highly valuable guidance for optimizing peanut N management and cultivation measures.

Background The peanut is one of the most important oil crops worldwide. Qualities and yields of peanut can be dramatically diminished by abiotic stresses particularly by drought. Therefore, it would be beneficial to gain a comprehensive understanding on peanut drought-responsive transcriptional regulatory activities, and hopefully to extract critical drought-tolerance-related molecular mechanism from it. Results In this study, two peanut Arachis hypogaea L. varieties, NH5 (tolerant) and FH18 (sensitive), which show significantly differential drought tolerance, were screened from 23 main commercial peanut cultivars and used for physiological characterization and transcriptomic analysis. NH5 leaves showed higher water and GSH contents, faster stomatal closure, and lower relative conductivity (REC) than FH18. Under the time-course of drought-treatments 0 h (CK), 4 h (DT1), 8 h (DT2) and 24 h (DT3), the number of down-regulated differential expressed genes (DEGs) increased with the progression of treatments indicating repressive impacts on transcriptomes by drought in both peanut varieties. Conclusions Nevertheless, NH5 maintained more stable transcriptomic dynamics than FH18. Furthermore, annotations of identified DEGs implicate signal transduction, the elimination of reactive oxygen species, and the maintenance of cell osmotic potential which are key drought-tolerance-related pathways. Finally, evidences from the examination of ABA and SA components suggested that the fast stomatal closure in NH5 was likely mediated through SA rather than ABA signaling. In all, these results have provided us a comprehensive overview of peanut drought-responsive transcriptomic changes, which could serve as solid foundation for further identification of the molecular drought-tolerance mechanism in peanut and other oil crops.

Belowground interactions mediated by root exudates are critical for the productivity and efficiency of intercropping systems. Herein, we investigated the process of microbial community assembly in maize, peanuts, and shared rhizosphere soil as well as their regulatory mechanisms on root exudates under different planting patterns by combining metabolomic and metagenomic analyses. The results showed that the yield of intercropped maize increased significantly by 21.05% (2020) and 52.81% (2021), while the yield of intercropped peanut significantly decreased by 39.51% (2020) and 32.58% (2021). The nitrogen accumulation was significantly higher in the roots of the intercropped maize than in those of sole maize at 120 days after sowing, it increased by 129.16% (2020) and 151.93% (2021), respectively. The stems and leaves of intercropped peanut significantly decreased by 5.13 and 22.23% (2020) and 14.45 and 24.54% (2021), respectively. The root interaction had a significant effect on the content of ammonium nitrogen (NH 4 + -N) as well as the activities of urease (UE), nitrate reductase (NR), protease (Pro), and dehydrogenase (DHO) in the rhizosphere soil. A combined network analysis showed that the content of NH 4 + -N as well as the enzyme activities of UE, NR and Pro increased in the rhizosphere soil, resulting in cyanidin 3-sambubioside 5-glucoside and cyanidin 3-O-(6-Op-coumaroyl) glucoside-5-O-glucoside; shisonin were significantly up-regulated in the shared soil of intercropped maize and peanut, reshaped the bacterial community composition, and increased the relative abundance of Bradyrhizobium . These results indicate that interspecific root interactions improved the soil microenvironment, regulated the absorption and utilization of nitrogen nutrients, and provided a theoretical basis for high yield and sustainable development in the intercropping of maize and peanut.

Early sowing has been extensively used in high-latitude areas to avoid drought stress during sowing; however, cold damage has become the key limiting factor of early sowing. To relieve cold stress, plants develop a series of physiological and biochemical changes and sophisticated molecular regulatory mechanisms. The biomembrane is the barrier that protects cells from injury as well as the primary place for sensing cold signals. Chilling tolerance is closely related to the composition, structure, and metabolic process of membrane lipids. This review focuses on membrane lipid metabolism and its molecular mechanism, as well as lipid signal transduction in peanut ( ) under cold stress to build a foundation for explicating lipid metabolism regulation patterns and physiological and molecular response mechanisms during cold stress and to promote the genetic improvement of peanut cold tolerance.

Background Salt stress has become a major threat to peanut yield and quality, and salt stress is particularly detrimental to seedling growth. Combined analysis of the physiology and transcriptomics of salt-tolerant variety (NH5) and salt-sensitive variety (FH23) under 200 mM NaCl stress was conducted to identify the key factors influencing the differences in salt tolerance and to investigate the potential regulatory mechanisms and hub genes associated with salt tolerance in peanuts. Results Malondialdehyde (MDA) content and electrolyte leakage rate were significantly increased under prolonged NaCl stress, with the increase in FH23 being even more pronounced. NH5 maintained intracellular osmotic homeostasis by accumulating free proline and soluble protein content. In addition, NH5 exhibited higher antioxidant enzyme activity. The net photosynthetic rate (Pn) of NH5 and FH23 decreased by 64.24% and 94.49% after 96 h of stress. The intercellular CO 2 concentration (Ci) of NH5 significantly decreased by 7.82%, while that of FH23 increased by 42.74%. This suggests that non-stomatal limiting factors were the primary cause of the decline in photosynthesis observed in FH23. Transcriptome analysis revealed the presence of 12,612 differentially expressed genes (DEGs) in response to salt stress, with FH23 exhibiting a greater number than NH5. The number of upregulated genes was significantly higher than that of downregulated genes at 24 h of salt stress, whereas the number of downregulated genes exceeded that of upregulated genes at 48 h. Subsequently, Weighted Gene Co-expression Network Analysis (WGCNA) was performed in conjunction with physiological data. Twenty-four hub genes of salt response were identified, which encoded delta-1-pyrroline-5-carboxylate synthase, aldehyde dehydrogenase, SNF1-related protein kinase, magnesium transporter, temperature-induced lipocalin-1, and ERF transcription factors. Conclusion A regulatory network for potential salt tolerance in peanuts has been constructed. The findings revealed distinct mechanisms of response to salt tolerance and identified candidate genes for further investigation.

Genomic selection is being used increasingly in plant breeding to accelerate genetic gain per unit time. One of the most important applications of genomic selection in maize breeding is to predict and select the best un-phenotyped lines in bi-parental populations based on genomic estimated breeding values. In the present study, 22 bi-parental tropical maize populations genotyped with low density SNPs were used to evaluate the genomic prediction accuracy ( ) of the six trait-environment combinations under various levels of training population size (TPS) and marker density (MD), and assess the effect of trait heritability ( ), TPS and MD on estimation. Our results showed that: (1) moderate values were obtained for different trait-environment combinations, when 50% of the total genotypes was used as training population and ~200 SNPs were used for prediction; (2) increased with an increase in , TPS and MD, both correlation and variance analyses showed that is the most important factor and MD is the least important factor on estimation for most of the trait-environment combinations; (3) predictions between pairwise half-sib populations showed that the values for all the six trait-environment combinations were centered around zero, 49% predictions had values above zero; (4) the trend observed in differed with the trend observed in / , and is the square root of heritability of the predicted trait, it indicated that both and / values should be presented in GS study to show the accuracy of genomic selection and the relative accuracy of genomic selection compared with phenotypic selection, respectively. This study provides useful information to maize breeders to design genomic selection workflow in their breeding programs.

Background Drought stress has negative effects on plant growth and productivity. In this study, a comprehensive analysis of physiological responses and gene expression was performed. The responses and expressions were compared between drought-tolerant (DT) and drought-sensitive (DS) peanut varieties to investigate the regulatory mechanisms and hub genes involved in the impact of drought stress on culture. Results The drought-tolerant variety had robust antioxidative capacities with higher total antioxidant capacity and flavonoid contents, and it enhanced osmotic adjustment substance accumulation to adapt to drought conditions. KEGG analysis of differentially expressed genes demonstrated that photosynthesis was strongly affected by drought stress, especially in the drought-sensitive variety, which was consistent with the more severe suppression of photosynthesis. The hub genes in the key modules related to the drought response, including genes encoding protein kinase, E3 ubiquitin-protein ligase, potassium transporter, pentatricopeptide repeat-containing protein, and aspartic proteinase, were identified through a comprehensive combined analysis of genes and physiological traits using weighted gene co-expression network analysis. There were notably differentially expressed genes between the two varieties, suggesting the positive roles of these genes in peanut drought tolerance. Conclusion A comprehensive analysis of physiological traits and relevant genes was conducted on peanuts with different drought tolerances. The findings revealed diverse drought-response mechanisms and identified candidate genes for further research.

Background Drought stress poses a critical constraint to plant growth by impairing photosynthetic efficiency in crops. Results Through transcriptome profiling of two peanut cultivars with contrasting drought tolerance, Fuhua18 (drought-sensitive, FH18) and Nonghua5 (drought-tolerant, NH5), we identified significant enrichment of differentially expressed genes in photosynthesis-related pathways. Notably, these genes were predominantly downregulated in FH18. Subsequent physiological analysis revealed cultivar-specific responses: Chlorophyll content decreased in FH18 but increased in NH5 after 24 h of drought treatment, accompanied by significant reductions in net photosynthetic rate (Pn) and water use efficiency (WUE) in both cultivars. The drought-induced physiological perturbations were further evidenced by elevated electrolyte leakage and activated antioxidant systems. To dissect photosynthetic apparatus dynamics, we implemented JIP-test analysis of chlorophyll fluorescence kinetics. Both cultivars exhibited substantial increases in Vj and Vi parameters at 24 h, while FH18 demonstrated a pronounced elevation in Vk during the O-J phase transition, suggesting severe impairment of the oxygen-evolving complex. Quantitative evaluation of photosynthetic performance indices revealed marked declines in PI abs and PI total , indicating systemic damage to both PSI and PSII under drought stress. Comparative analysis identified 11 traits showing significant inter-cultivar variation, particularly in PSII reaction center parameters including PI abs , DI 0 /RC, RE 0 /RC, ABS/RC, and TR 0 /RC. Conclusion These findings provide mechanistic insights into cultivar-dependent photosynthetic responses to drought stress, offering potential biomarkers for breeding drought-resilient peanut varieties.

Background Pod size is an important yield target trait for peanut breeding. However, the molecular mechanism underlying the determination of peanut pod size still remains unclear. Results In this study, two peanut varieties with contrasting pod sizes were used for comparison of differences on the transcriptomic and endogenous hormonal levels. Developing peanut pods were sampled at 10, 15, 20, 25 and 30 days after pegging (DAP). Our results showed that the process of peanut pod-expansion could be divided into three stages: the gradual-growth stage, the rapid-growth stage and the slow-growth stage. Cytological analysis confirmed that the faster increase of cell-number during the rapid-growth stage was the main reason for the formation of larger pod size in Lps. Transcriptomic analyses showed that the expression of key genes related to the auxin, the cytokinin (CK) and the gibberellin (GA) were mostly up-regulated during the rapid-growth stage. Meanwhile, the cell division-related differentially expressed genes (DEGs) were mostly up-regulated at 10DAP which was consistent with the cytological-observation. Additionally, the absolute quantification of phytohormones were carried out by liquid-chromatography coupled with the tandem-mass-spectrometry (LC–MS/MS), and results supported the findings from comparative transcriptomic studies. Conclusions It was speculated that the differential expression levels of TAA1 and ARF (auxin-related), IPT and B-ARR (CK-related), KAO , GA20ox and GA3ox (GA-related), and certain cell division-related genes ( gene-LOC112747313 and gene-LOC112754661 ) were important participating factors of the determination-mechanism of peanut pod sizes. These results were informative for the elucidation of the underlying regulatory network in peanut pod-growth and would facilitate further identification of valuable target genes.