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Bama County is a world-famous longevity county in the Guangxi Province, China. Bama hemp is a traditional seed used in hemp cultivation in the Bama County. The seeds contain abundant unsaturated fatty acids, particularly linoleic acid (LA) and linolenic acid in the golden ratio. These two substances have been proven to be related to human health and the prevention of various diseases. However, the seed development and seed oil accumulation mechanisms remain unclear. This study employed a combined analysis of physiological, transcriptomic, and metabolomic parameters to elucidate the fatty acid formation patterns in Bama hemp seeds throughout development. We found that seed oil accumulated at a late stage in embryo development, with seed oil accumulation following an “S″-shaped growth curve, and positively correlated with seed size, sugar content, protein content, and starch content. Transcriptome analysis identified genes related to the metabolism of LA, α-linolenic acid (ALA), and jasmonic acid (JA). We found that the FAD2gene was upregulated 165.26 folds and the FAD3gene was downregulated 6.15 folds at day 21. Metabolomic changes in LA, ALA, and JA compounds suggested a competitive relationship among these substances. Our findings indicate that the peak period of substance accumulation and nutrient accumulation in Bama hemp seeds occurs during the midstage of seed development (day 21) rather than in the late stage (day 40). The results of this research will provide a theoretical basis for local cultivation and deep processing of Bama hemp.

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Graphical Abstract:

To meet the rising demand for energy storage, it is essential to achieve further improvements in the energy storage density and efficiency of composites based on dielectric polymers. Herein, Boron nitride nano sheets (BNNS) with high breakdown strength and high thermal conductivity was introduced into the matrix of polyvinylidene fluoride hexafluoropropylene (P (VDF-HFP)). Via synchronous heating and stirring treatment, BNNS were well dispersed in P(VDF-HFP) with increased fluidity due to the rise of temperature. With the incorporation of 7 wt% BNNS, the composite achieved high energy storage density of 21 J/cm3at 492 MV/m and high efficiency of 80.2 % concurrently, outperforms most previous polymer-based composite dielectric energy storage materials. This is attributed to the fact that BNNS can induce the formation of P(VDF-HFP) crystalline phase, and the simultaneous heating process improves filler dispersion to extend the breakdown path and disperse electron heat accumulation.