Raffinose family oligosaccharides (RFOs) are widespread across the plant kingdom, and their concentrations are related to the environment, genotype, and harvest time. RFOs are known to carry out many functions in plants and humans. In this paper, we provide a comprehensive review of RFOs, including their beneficial and anti-nutritional properties. RFOs are considered anti-nutritional factors since they cause flatulence in humans and animals. Flatulence is the single most important factor that deters consumption and utilization of legumes in human and animal diets. In plants, RFOs have been reported to impart tolerance to heat, drought, cold, salinity, and disease resistance besides regulating seed germination, vigor, and longevity. In humans, RFOs have beneficial effects in the large intestine and have shown prebiotic potential by promoting the growth of beneficial bacteria reducing pathogens and putrefactive bacteria present in the colon. In addition to their prebiotic potential, RFOs have many other biological functions in humans and animals, such as anti-allergic, anti-obesity, anti-diabetic, prevention of non-alcoholic fatty liver disease, and cryoprotection. The wide-ranging applications of RFOs make them useful in food, feed, cosmetics, health, pharmaceuticals, and plant stress tolerance; therefore, we review the composition and diversity of RFOs, describe the metabolism and genetics of RFOs, evaluate their role in plant and human health, with a primary focus in grain legumes.

Biotic stresses including fungal infections result in increased production of flavonoid compounds, including 3-deoxyanthocyanidins (3-DAs) in the leaf tissues of Sorghum bicolor (L.) Moench. Our objectives were to determine if sorghum genotypic variation influenced root flavonoid and 3-DA concentrations and rhizosphere microbial communities and to identify how these relationships were impacted by abiotic stress. We evaluated root chemicals and rhizosphere microbiomes of five near-isogenic lines of sorghum before and after a late-season frost. Roots were analyzed for total flavonoids, total phenolics, 3-DA concentrations and antioxidant activity. Amplicon sequencing of 16S rRNA genes and ITS regions was performed on rhizosphere soils. Concentrations of luteolinidin (a 3-DA) and total flavonoids differed between several lines before frost, but these relationships changed after frost. Luteolinidin increased in three lines after frost, while total flavonoids decreased in all the lines after frost. Lines that differed in luteolinidin and total flavonoid concentrations before frost were different from those after frost. Rhizosphere community compositions also differed before and after frost, but only fungal community compositions differed among sorghum lines. Bacterial community compositions were highly correlated with total flavonoid and luteolinidin concentrations. Furthermore, a greater number of bacterial taxa were correlated with total flavonoids and luteolinidin compared to fungal taxa. Collectively, this study provides evidence that plant genotypic variation influences root flavonoids and rhizosphere community composition and that these relationships are impacted by frost. Plant-microbe interactions and secondary metabolite production may be important components to include for selective breeding of sorghum for frost stress tolerance.

Sorghum accumulates epi-cuticular wax (EW) in leaves, sheaths, and culms. EW reduces the transpirational and nontranspirational (nonstomatal) water loss and protects the plant from severe drought stress in addition to imparting resistance against insect pests. Results presented here are from the analysis of EW content of 387 diverse sorghum accessions and its genome-wide association study (GWAS). EW content in sorghum leaves ranged from 0.1 to 29.7 mg cm -2 with a mean value of 5.1 mg cm -2 . GWAS using 265,487 single nucleotide polymorphisms identified thirty-seven putative genes associated (P \ 9.89E-06) with EW biosynthesis and transport in sorghum. Major EW biosynthetic genes identified included 3-Oxoacyl-[acyl-carrier-protein (ACP)] synthase III, an Ankyrin repeat protein, a bHLH-MYC, and an R2R3-MYB transcription factor. Genes involved in EW regulation or transport included an ABC transporter, a Lipid exporter ABCA1, a Multidrug resistance protein, Inositol 1, 3, 4-trisphosphate 5/6-kinase, and a Cytochrome P450. This GWA study thus demonstrates the potential for genetic manipulation of EW content in sorghum for better adaptation to biotic and abiotic stress.Keywords ABC transporters Á Acyl carrier protein Á Epicuticular wax Á Fatty acid synthase Á Very long-chain fatty acids Á Single nucleotide polymorphism For the special issue of ''Plant Genetics and Genomics Conference''.

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Arabidopsis thaliana has a wide elevational range and much of its diversity may be associated with local adaptation to elevation. We took a multi-regional view of the genomics and physiology of elevational adaptation in Arabidopsis, with >200 ecotypes, including 17 newly collected from Africa. We measured plant responses to potential high elevation stressors: low pCO2, high light, and night freezing and conducted genome-wide association studies (GWAS). We found evidence of an adaptive cline in the western Mediterranean with low δ13C/early flowering at low elevations to high δ13C/late flowering at high elevations. By contrast, central Asian high elevation ecotypes flowered earlier. Antioxidants and pigmentation under high light and freezing showed regional differentiation but not elevational clines and may be associated with maladaptive plasticity. We found natural variation in non-photochemical quenching (NPQ) kinetics in response to chilling and fluctuating light, though with an unclear role in local adaptation. There were several candidate genetic loci mapped, including the ascorbate transporter PHT4;4 (associated with antioxidants) that influences the xanthophyll cycle, and may be involved in local adaptation to Morocco. Our study shows how the ecological strategies and genetic loci causing local adaptation to elevation change across regions and contribute to diversity in Arabidopsis.