Peanut Institute

Background The practice of tobacco monoculture usually leads to increased occurrence of soil-borne diseases and reduced yield and quality, posing a significant obstacle to sustainable farming. The soil microbiome is central to soil health, but the mechanisms by which crop rotation alleviates monoculture-related obstacles by reconstructing microbial communities and their interaction networks remain poorly understood. Methods A field study was conducted in two regions to compare tobacco grown on soils after rotation (with wheat or rapeseed) and tobacco grown on soils with continuous tobacco cropping. A comprehensive analysis was performed on soil physicochemical properties, enzyme activities, microbial biomass, 16S rRNA bacterial and ITS fungal gene sequencing, microbial co-occurrence networks and phenotypic data, including tobacco yield, disease index and chemical quality of cured tobacco. A multi-omics coupling framework was constructed to integrate environmental variables, community structure and phenotype. Results Crop rotation notably increased the content of available potassium in the soil and enhanced the activities of key enzymes involved in carbon and phosphorus cycling, such as β-glucosidase, sucrase and acid phosphatase. These changes led to improved nutrient availability. Across the two regions, crop rotation consistently restructured both bacterial and fungal communities, enriching beneficial taxa, including Chitinophagaceae , Rhodanobacteraceae , Xanthobacteraceae , Cercophora and Montagnula , while suppressing the proliferation of potential fungal pathogens. The microbial co-occurrence networks under rotation conditions were more intricate, cooperative and functionally integrated. Path analysis, incorporating composite variables, revealed a comprehensive causal pathway: crop rotation enhances the abundance of beneficial microbes and increases network complexity, which, in turn, improves the soil health indexes. This ultimately results in higher tobacco yield, reduced disease incidence and superior chemical and sensory quality of the cured tobacco.

DNA methylation plays important roles in silencing of transgenes, endogenous genes, and transposable elements (TEs). To identify genes involved in antagonizing transcriptional or DNA hypermethylation-induced gene silencing, a genetic screening was conducted and thus a tho2-8 mutant was recovered. THO2 is a major component of the THO/TREX (Transcription-Export) complex, which plays essential roles in mRNA export. The tho2-8 mutation caused overaccumulation of DNA methylation on a d35S promoter ahead of LUC, suggesting its roles in antisilencing of transgenes. This mutation also resulted in significant genome-wide alterations in DNA methylation in a locus-specific manner, including 2513 hyper-DMRs and 1717 hypo-DMRs. The hyper-DMRs in the tho2-8 mutant not only exhibited a considerable overlap with those in DNA demethylation mutants (like ros1-7), but also with hypo-DMRs from nrpd1-3 and nrpe1-11 mutants, demonstrating that THO2 is able to protect those loci targeted by DNA demethylation and/or RdDM pathways from hypermethylation. The tho2-8 mutant also contained a plethora of CHH hypo-DMRs, which overlapped in large numbers with those from the nrpd1-3 and nrpe1-11 mutants, indicating that THO2 is required for the establishment/maintenance of DNA methylation at many loci. Additionally, the tho2-8 mutation caused an increase in overall 24-nt siRNA levels and many upregulated and downregulated DEGs/DETEs. The effects of THO2 on DNA methylation patterns appeared to be associated with the functioning of Pol IV and Pol V because THO2 physically interacted with NRPD7 and was necessary for normal accumulation levels of several Pol V-dependent IGNs' transcripts. Thus, this study provided valuable insights into new roles of THO2 in DNA methylation patterning.

Cultivated peanut (Arachis hypogaea, AABB genome) is an allotetraploid species that likely originated from hybridization between the two wild diploid species A. duranensis (AA) and A. ipaensis (BB). Chromosome identification and genomic evolution studies in Arachis species have encountered significant challenges due to the absence of consensus karyotypes. In this study, we developed the first "barcode" consensus karyotype for peanut using single-copy oligonucleotide probe libraries. This karyotype was applied to identify interspecific hybrids and radiation-induced chromosomal variants, correlate pseudochromosomes with physical chromosomes, and determine chromosomal homoeologous relationships among Arachis species. Analyses of karyotype, chloroplast phylogeny, and similarity heatmaps revealed that A. duranensis and A. ipaensis exhibited the highest similarity to the subgenome of A. hypogaea; certain A-genome species displayed high heterozygosity; and, despite harboring distinct chloroplast genomes, the nuclear genomes of various botanical varieties of peanut were all most similar to A. duranensis accessions from the Rio Seco region in Argentina. Combined with the geographical distribution of A. ipaensis, we propose that outcrossing events may have contributed to the generation of A. duranensis accessions with distinct chloroplasts; subsequently, these accessions likely hybridized with A. ipaensis, leading to the formation of different peanut botanical varieties within an area extending from southern Bolivia to the Rio Seco region. These findings underscore the broad applicability of our new karyotype for distant hybridization, chromosomal identification, and genome evolution research in peanut.

Abstract Stress gradient hypothesis proposes that the plant interaction tends to convert from competition to facilitation when facing accelerating stress. The present study aims to explore the interaction between two co-existing wetland plant invaders – Alternanthera philoxeroides and Myriophyllum aquaticum with exposure to flooding stress. Different plant assemblages including monospecific (single individual per species), homospecific (two individuals of same species) and heterospecific (two individuals of different species) treatments were subjected to different flooding regimes including mesic habitat, constant flooding and fluctuating flooding. The plant interaction was evaluated by biomass accumulation, biomass allocation and relative competition intensity index (RCI). We found that the biomass accumulation and allocation of A. philoxeroides were consistent across different treatments of community assemblage and flooding regime, while the root mass, biomass and root mass allocation of M. aquaticum significantly increased at the presence of A. philoxeroides . Moreover, the RCI of M. aquaticum decreased at the presence of A. philoxeroides . Especially, the RCI of M. aquaticum was 0.06 in the homospecific community, while that of M. aquaticum was -0.82 in the heterospecific treatment under fluctuating flooding condition. Overall, Alternanthera philoxeroides facilitated M. aquaticum , especially under fluctuating flooding condition, which complies with the stress gradient hypothesis. The water level drawdown can benefit the impedance of the growth of M. aquaticum and the deceleration of the co-invasion of A. philoxeroides and M. aquaticum .

Antioxidants are critical components of the body's defense system, providing protection against cell-damaging free radicals responsible for oxidative damage of biomolecules. Humans benefit from the consumption of plants with high antioxidant content, which have been shown to positively impact health. In plant physiology, antioxidants provide protection from biotic and abiotic stress, particularly during the development of seeds and germination. Peanut seeds and seed coats have been shown to contain several beneficial antioxidants and are a good source of phytonutrients. Seed coat color can vary greatly and impact the antioxidant capacity of the edible portion of the peanut. Additionally, the seed coat can provide bitter notes in products, affecting their palatability and potentially negating the beneficial properties of the antioxidants present. A total of 42 accessions from the Germplasm Resource Information Network (GRIN) with a variety of seed coat colors were obtained and analyzed for total antioxidant capacity to provide a baseline assessment of the distribution of antioxidants in kernel versus seed coats. The results demonstrated that seed coat color somewhat impacts antioxidant capacity, and 56-88% of the total antioxidant capacity resides in the seed kernel. Three control samples, not part of the germplasm collection, were roasted and prepared for analysis by the descriptive sensory panel. Seed coats were added back to the roasted paste in increasing proportion for analysis by the panel, and perceptions regarding bitterness and overall organoleptic properties were noted. Based on the results of this study, several accessions were selected and then planted for increase and potential crossbreeding with appropriate commercial cultivars. This information could be used to selectively add antioxidant capacity to peanut breeding programs to provide additional health benefits to consumers without compromising the sensory perception and desirability and peanut products in nutrition.

Este artigo explora a herança epigenética e a memória genética, destacando como modificações epigenéticas, tais como a metilação do DNA e as alterações pós-traducionais das histonas, desempenham um papel crucial na regulação da expressão gênica e na transmissão de informações biológicas através das gerações. Através de uma revisão de literatura abrangente, discute-se a hipótese de Hebb e os recentes avanços em experimentos genéticos com modelos animais que ilustram a detecção de coincidências sinápticas mediadas por receptores NMDA. Evidências de estudos em leveduras, roedores e Caenorhabditis elegans são apresentadas para demonstrar como marcas epigenéticas podem influenciar a memória, o aprendizado e a saúde transgeracional. Um relato pessoal é utilizado para contextualizar a relevância deste fenômeno na experiência humana, conectando a teoria científica com observações individuais. A memória genética refere-se à ideia de que certos tipos de memórias ou informações podem ser transmitidos geneticamente de uma geração para outra. Esse conceito, embora intrigante, é amplamente estudado e debatido dentro da neurociência e da genética. O artigo explora a origem e a base biológica da memória genética com base nas descobertas científicas.

Leaf senescence represents the final stage of leaf development, involving transcription factors (TFs)-mediated genetic reprogramming events. The timing of crop leaf senescence has a major influence on the yield and quality of crop in agricultural production. As important regulator of plant growth, the significance of TFs in the regulation of leaf senescence have been highlighted in various plant species by recent advances in genetics. However, studies on underlying molecular mechanisms are still not adequately explained. In this study, for analyzing the regulation of TFs on senescence of tobacco leaves, we combined gene differential expression analysis with weighted gene co-expression network analysis (WGCNA) to analyze the time-series gene expression profiles in senescing tobacco leaf. Among 3517 TF genes expressed in tobacco leaves, we identified 21, 35, and 183 TFs that were associated with early, middle, and late stages of tobacco leaf senescence, respectively. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) annotation results reveal that these senescence response TFs are correlated with several biological pathways such as plant hormone signal transduction, ubiquitin mediated proteolysis and MAPK signaling pathway, indicating the roles of TFs in regulating leaf senescence. Our results provide implications for future studies of the potential regulatory mechanisms of TFs involved in senescence of tobacco leaves.

O Diabetes Mellitus tipo 1 (DM1) é uma condição crônica que afeta predominantemente crianças e adolescentes, caracterizada pela destruição autoimune das células beta pancreáticas, resultando em deficiência severa de insulina. Este estudo investiga não apenas os aspectos clínicos e fisiopatológicos do DM1, mas também seus impactos psicossociais profundos. O tratamento do DM1 envolve insulinoterapia intensiva desde o diagnóstico, visando manter o controle glicêmico e prevenir complicações graves como a cetoacidose diabética. A educação em saúde desempenha um papel crucial no manejo eficaz, capacitando pacientes e familiares a enfrentarem os desafios diários com segurança e autonomia. Estratégias como educação nutricional, estímulo à atividade física e suporte psicológico são fundamentais para melhorar a qualidade de vida e reduzir o impacto da doença. Além disso, são observados os desafios únicos enfrentados por crianças e adolescentes com DM1, incluindo o impacto emocional, social e educacional da doença. A qualidade de vida desses jovens pode ser comprometida, requerendo suporte contínuo da família, profissionais de saúde e comunidade. Avanços recentes, como sistemas de infusão contínua de insulina e monitoramento glicêmico contínuo, oferecem novas perspectivas para um controle mais preciso e menos invasivo, promovendo uma melhor adesão ao tratamento e uma vida mais próxima do normal para os pacientes com DM1. Em suma, este estudo reforça a necessidade de abordagens multidisciplinares para enfrentar os desafios do DM1, não apenas focando no controle metabólico, mas também na melhoria da qualidade de vida dos pacientes afetados por esta condição complexa e exigente.