High oil and protein content make tetraploid peanut a leading oil and food legume. Here we report a high-quality peanut genome sequence, comprising 2.54 Gb with 20 pseudomolecules and 83,709 protein-coding gene models. We characterize gene functional groups implicated in seed size evolution, seed oil content, disease resistance and symbiotic nitrogen fixation. The peanut B subgenome has more genes and general expression dominance, temporally associated with long-terminal-repeat expansion in the A subgenome that also raises questions about the A-genome progenitor. The polyploid genome provided insights into the evolution of Arachis hypogaea and other legume chromosomes. Resequencing of 52 accessions suggests that independent domestications formed peanut ecotypes. Whereas 0.42–0.47 million years ago (Ma) polyploidy constrained genetic variation, the peanut genome sequence aids mapping and candidate-gene discovery for traits such as seed size and color, foliar disease resistance and others, also providing a cornerstone for functional genomics and peanut improvement.

GOLDEN2-LIKE (GLK) is a member of the myeloblastosis (MYB) family transcription factor and it plays an important role in the regulation of plastid development and stress tolerance. In this study, a gene named AhGLK1b was identified from a cultivated peanut showing down-regulation in response to low calcium with a complete open reading frame (ORF) of 1212 bp. The AhGLK1b has 99.26% and 96.28% sequence similarities with its orthologs in Arachis ipaensis and A. duranensis, respectively. In the peanut, the AhGLK1b was localized in the nucleus and demonstrated the highest expression in the leaf, followed by the embryo. Furthermore, the expression of AhGLK1b was induced significantly in response to a bacterial pathogen, Ralstonia solanacearum infection. Ectopic expression of AhGLK1b in Arabidopsis showed stronger resistance against important phytopathogenic fungi S. sclerotiorum. It also exhibited high resistance to infection of the bacterial pathogen Pst DC3000. AhGLK1b-expressing Arabidopsis induced defense-related genes including PR10 and Phox/Bem 1 (PBI), which are involved in multiple disease resistance. Taken together, the results suggest that AhGLK1b might be useful in providing dual resistance to fungal and bacterial pathogens as well as tolerance to abiotic stresses.

Peanut (Arachis hypogaea L.) is an important food and feed crop worldwide and is affected by various biotic and abiotic stresses. The cellular ATP levels decrease significantly during stress as ATP molecules move to extracellular spaces, resulting in increased ROS production and cell apoptosis. Apyrases (APYs) are the nucleoside phosphatase (NPTs) superfamily members and play an important role in regulating cellular ATP levels under stress. We identified 17 APY homologs in A. hypogaea (AhAPYs), and their phylogenetic relationships, conserved motifs, putative miRNAs targeting different AhAPYs, cis-regulatory elements, etc., were studied in detail. The transcriptome expression data were used to observe the expression patterns in different tissues and under stress conditions. We found that the AhAPY2-1 gene showed abundant expression in the pericarp. As the pericarp is a key defense organ against environmental stress and promoters are the key elements regulating gene expression, we functionally characterized the AhAPY2-1 promoter for its possible use in future breeding programs. The functional characterization of AhAPY2-1P in transgenic Arabidopsis plants showed that it effectively regulated GUS gene expression in the pericarp. GUS expression was also detected in flowers of transgenic Arabidopsis plants. Overall, these results strongly suggest that APYs are an important future research subject for peanut and other crops, and AhPAY2-1P can be used to drive the resistance-related genes in a pericarp-specific manner to enhance the defensive abilities of the pericarp.

Aflatoxin contamination in peanuts poses a significant challenge to global food safety and trade. Current strategies for managing aflatoxins for pre- and post-harvest aflatoxin contamination in peanuts include both conventional and advanced approaches. Traditional breeding efforts have identified several key genetic markers associated with resistance, and marker-assisted selection has been improving the efficiency of developing resistant peanut varieties. Biotechnological innovations, such as RNA interference (RNAi) and transgenic methods, have shown promising results in reducing aflatoxin production by Aspergillus species. In this chapter, we present in-depth analyses of peanut responses to aflatoxin contamination, incorporating insights from functional genomics studies. Molecular genetics tools for aflatoxin management, such as germplasm evaluation and the exploration of genetic factors influencing aflatoxin resistance, are highlighted. We present fundamental strategies for mitigating peanut aflatoxin contamination by integrating the application of omics tools, including functional genomics, to unravel molecular insights. Genomics-assisted breeding seems to be a very promising approach for developing aflatoxin-resistant peanut varieties. Finally, we propose future research directions, emphasizing addressing complex genetics factors regulating aflatoxin contamination, their underlying mechanisms, and the application of gene-editing technologies to develop peanut varieties with durable resistance. <!----> <!----> <!----> <!---->

| Current experiment was performed in 2019 at Arid Zone Research Center, Dera Ismail Khan, KP, to study Mungbean ( Vigna radiata L.) flushes and their contribution towards the final yield. Among the goals were the quantification of mungbean flowering flushes to final yield, identification of short duration variety, to recognize varieties suitable for water-deficient areas, and varieties suitable for cotton crop intercropping before reaching their maximum canopy level. The analysis was carried out in randomized complete block design (RCBD) with three replications of split plot arrangement; varieties (NM-2011, Inqelab Mung, Dera Mung, and NM-98) were allocated in the main plot and sub-plots were held at various flowering flushes. The analyzed data revealed that the percentage of pods plant -1 , weight pod -1 , 1000 grain weight, grain yield, and harvest index were significantly affected by different varieties, and their interaction with the harvest at various flowering flushes. Inqelab Mung give higher yield compared to other varieties by producing 26 and 37 percent (63 percent) of its total yield in the 1 st and 2 nd flushes, respectively, with maturity for both flushes in around 63 days. In addition, its yield was higher than NM-2011, Dera Mung, and NM-98 by 21 %, 51 %, and 40 %, respectively. Cultivar Inqelab Mung may be recommended for planting in rain-fed conditions where the supply of water for the second and third irrigation is uncertain for farmers. In addition, through adding nitrogen via nodulation, it can also be intercropped with cotton as it can give fair yield without presenting any competition with cotton crop.