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To assess the mechanism of the pharmacokinetic interaction between piperacillin and tazobactam, renal excretion and pharmacokinetic studies of piperacillin/tazobactam were investigated in normal and bacteremia rats. A bacteremia model was established to investigate the pharmacokinetic properties of piperacillin and tazobactam under different conditions. Renal slices were taken to examine the uptake of piperacillin and tazobactam. Pharmacokinetic studies of β-lactamase in rats were performed to study the contribution of rOat1/3 to the inhibition of tazobactam on β-lactamase. The AUC (from 2.93 ± 0.58 to 6.52 ± 1.44 mg·min/ml) and the plasma clearance (CLP) (from 2.41 ± 1.20 to 0.961 ± 0.212 ml/min/kg) of tazobactam were both altered after the intravenous coadministration of piperacillin and tazobactam in the bacteremia rats. The renal clearance (CLR) of tazobactam decreased from 1.30 ± 0.50 to 0.361 ± 0.043 ml/min/kg. In summary, there was a beneficial interaction between piperacillin and tazobactam mediated by rOat1 and rOat3. Piperacillin enhances the inhibitory effect of tazobactam on β-lactamase through the inhibition of rOat1 and rOat3 in rats. The contribution rate of rOat1/3 for the synergistic effect was 20% when the two drugs were coadministered., Graphical abstract Image, graphical abstract

Cultivated peanut (Arachis hypogaea) is an allotetraploid crop planted in Asia, Africa, and America for edible oil and protein. To explore the origins and consequences of tetraploidy, we sequenced the allotetraploid A. hypogaea genome and compared it with the related diploid Arachis duranensis and Arachis ipaensis genomes. We annotated 39 888 A-subgenome genes and 41 526 B-subgenome genes in allotetraploid peanut. The A. hypogaea subgenomes have evolved asymmetrically, with the B subgenome resembling the ancestral state and the A subgenome undergoing more gene disruption, loss, conversion, and transposable element proliferation, and having reduced gene expression during seed development despite lacking genome-wide expression dominance. Genomic and transcriptomic analyses identified more than 2 500 oil metabolism-related genes and revealed that most of them show altered expression early in seed development while their expression ceases during desiccation, presenting a comprehensive map of peanut lipid biosynthesis. The availability of these genomic resources will facilitate a better understanding of the complex genome architecture, agronomically and economically important genes, and genetic improvement of peanut.

Molecular genetic maps of crop species can be used in a variety of ways in breeding and genomic research such as identification and mapping of genes and quantitative trait loci (QTLs) for morphological, physiological and economic traits of crop species. However, a comprehensive genetic linkage map for cultivated peanut has not yet been developed due to the extremely low frequency of DNA polymorphism in cultivated peanut. In this study, 142 recombinant inbred lines (RILs) derived from a cross between Yueyou 13 and Zhenzhuhei were used as mapping population in peanut (Arachis hypogaea L.). A total 652 pairs of genomic-SSR primer and 392 pairs of EST-SSR primer were used to detect the polymorphisms between the two parents. 141 SSR primer pairs, 127 genomic-SSR and 14 EST-SSR ones, which can be used to detect polymorphisms between the two parents, were selected to analyze the RILs population. Thus, a linkage genetic map which consists of 131 SSR loci in 20 linkage groups, with a coverage of 679 cM and an average of 6.12 cM of inter-maker distance was constructed. The putative functions of 12 EST-SSR markers located on the map were analyzed. Eleven showed homology to gene sequences deposited in GenBank. This is the first report of construction of a comprehensive genetic map with SSR markers in peanut (Arachis hypogaea L.). The map presented here will provide a genetic framework for mapping the qualitative and quantitative trait in peanut.