Superoxide dismutases (SODs) are crucial in safeguarding plants against reactive oxygen species (ROS) toxicity caused by abiotic or biotic factors. Although recent research has revealed the involvement of the SOD gene family in plant biological processes, the understanding of the SOD gene family in peanut remains inadequate. This study comprehensively characterizes the SOD gene family in the peanut genome. A total of 25 AhSOD genes were identified and subsequently categorized into three subfamilies: sixteen AhCSDs, six AhFSDs, and three AhMSDs according to the phylogenetic tree. A comprehensive analysis revealed that the AhSOD genes underwent segmental duplications. The majority of AhSOD genes exhibited conserved exon–intron and motif structures within the same subfamily. The examination of cis-acting elements within the promoter regions of SOD genes revealed that the expression of AhSOD was subject to regulation by plant hormones, as well as responses to defense and stress. RNA-seq analysis showed expression diversity of AhSOD genes in various tissues and cold, drought, and salt stresses. Furthermore, the regulation of AhSOD gene expression is anticipated to involve numerous transcription factors. The gene ontology annotation results validate the role of AhSOD genes in various stress stimuli, SOD activity, reactive oxygen species metabolic processes, and cellular oxidant detoxification processes. This investigation serves as the initial genome-wide analysis of the AhSOD gene family, providing a basis for comprehending the function of the AhSOD gene family and enhancing plant tolerance to cold, drought, and salt stresses.

High oleic acid peanut (HOAP) is extensively embraced in China because of its high nutritional value and enhanced oxidative stability. However, its dissemination has been severely constrained in high altitude and high latitude areas due to chilling stress during sowing, resulting in significant yield loss in these regions. Despite the lack of understanding of the molecular mechanisms underlying low temperature germination (LTG) in HOAP, discovering the quantitative trait loci (QTL) that confer this trait will undoubtedly benefit breeding efforts. In the present study, we identified putative genomic regions and single nucleotide polymorphisms (SNPs) that govern LTG tolerance of HOAP in an F₂ population derived from the cross of chilling-tolerant YH65 and chilling-sensitive FL14 using bulk segregant analysis (BSA). Analysis of ΔSNP-index and Euclidean distance (ED) value association pinpointed the overlapped region to a 2.29 Mb interval on chromosome A05. The candidate interval showed that 122 genes were significantly related to response to abiotic stress and plant–pathogen interaction. Furthermore, an SNP site associated with LTG tolerance was discovered. The SNP site was employed as a Kompetitive Allele Specific PCR (KASP) marker and validated in a universal peanut panel. These findings may provide valuable insight into the molecular mechanism underpinning LTG tolerance and facilitate marker-assisted selective breeding in HOAP.

As an important source of vegetable oil, peanut (Arachis hypogea L.) with both adequate tolerance and high-oleate could be a profitable choice in saline-alkali soil. In our study, two high-oleic peanut lines derived from the same cross and differing in saline-alkali response were initially identified from our previous field evaluation. In this study they were subjected to saline-alkali stress in pot culture, and their transcriptomes were analyzed. 16L1 possessed multiple characteristics related to saline-alkali stress tolerant, including well-developed green leaves, more pods, elevated proline, high levels of superoxide dismutase, catalase, peroxidase and strong photosynthetic capacity. According to the correlation of various indicators, we have established high-oleic peanut biological saline-alkali tolerance and physiological saline-alkali evaluation system. Ten differentially expressed genes (DEGs) responding to saline-alkali stress were characterized and confirmed by quantitative realtime reverse transcription PCR. A series of analyses of DEGs revealed the importance of secondary metabolites, osmotic adjustment substances, plant hormone signal transduction, and protein kinase in peanut saline-alkali tolerance. The output of this study will help to understand the saline-alkali tolerant mechanism and provide a reference for peanut saline-alkali tolerance.

Long-term continuous monocropping of foxtail millet (Setaria italica) in China has increased crop vulnerability to emerging diseases and threatens yield stability and grain quality. This practice may also influence inoculum carryover and host–pathogen interactions, making foxtail millet health a central issue for sustainable production. This study reports the first occurrence in China of a previously undescribed bacterial leaf disease of foxtail millet. Early symptoms are characterized by water-soaked lesions at leaf tips that spread basipetally along the veins and gradually desiccate as the tissue dehydrates. Koch’s postulates were fulfilled to isolate and identify the causal agent. Multilocus sequence analysis of three concatenated housekeeping genes (gyrB, infB, and rpoB) classified the pathogen as Pantoea ananatis. The isolate was further characterized for metabolic profile; its colonization pattern and spatial distribution within foxtail millet tissues were elucidated, revealing features of host–pathogen interaction. A high-quality de novo whole-genome assembly was generated, and candidate virulence determinants were identified by integrated genome annotation and cell wall hydrolase activity assays. This genomic resource is intended as a supporting tool for plant protection research, including disease surveillance, resistance breeding, and management. Collectively, this study represents the first report of P. ananatis causing bacterial leaf disease on foxtail millet in China. It clarifies the colonization and distribution of the pathogen in host tissues, reveales reveals its interaction characteristics with foxtail millet, and provided genomic resources to support research on foxtail millet health protection and plant protection under continuous cropping conditions.

Peanut (Arachis hypogaea L.) is a globally vital oil and cash crop. However, frequent cold stress severely compromises its yield stability. To address this challenge, we conducted quantitative trait locus (QTL) mapping for two cold tolerance-associated traits, namely relative emergence rate (RER) and relative emergence index (REI), across four distinct environments using a recombinant inbred line (RIL) population derived from the cold-tolerant landrace Silihong and cold-sensitive cultivar Jinonghei 3. Two core QTLs associated with cold tolerance were detected, including qRER6 stable across all environments with PVE of 4.91–5.15% and a co-localized QTL qRER18.1/qREI18.2 on chromosome 18 that governs both target traits with PVE of 14.56–14.71% and 10.34%. Through integrated analysis of QTL mapping and Weighted gene co-expression network analysis (WGCNA), Arahy.657RUG was identified as a candidate cold tolerance gene and designated Ahcold18. Differential expression analysis and heterologous overexpression in Arabidopsis thaliana under freezing stress (−9 °C) showed that Ahcold18 enhances plant survival under low-temperature stress, suggesting a general role in cold tolerance that warrants further investigation in the context of peanut chilling tolerance. A gene-based KASP marker (KASP-2374669), developed from variant sites within Ahcold18, showed preliminary association with RER and REI in the RIL population; however, further validation in diverse germplasm is required to confirm its utility for marker-assisted selection. This study provides a critical genetic resource and a precise technical tool for marker-assisted breeding of cultivated peanut with cold tolerance.