Crop management, genotypes, and environmental factors affect soyasaponin B concentration in soybean

Salicylic Acid's impact on Sedum alfredii growth and cadmium tolerance: Comparative physiological, transcriptomic, and metabolomic study

With the acceleration of industrialization, Cd pollution has emerged as a major threat to soil ecosystem health and food safety. Hyperaccumulating plants like Sedum alfredii Hance are considered to be used as part of an effective strategy for the ecological remediation of Cd polluted soils. This study delved deeply into the physiological, transcriptomic, and metabolomic responses of S. alfredii under cadmium (Cd) stress when treated with exogenous salicylic acid (SA). We found that SA notably enhanced the growth of S. alfredii and thereby increased absorption and accumulation of Cd, effectively alleviating the oxidative stress caused by Cd through upregulation of the antioxidant system. Transcriptomic and metabolomic data further unveiled the influence of SA on photosynthesis, antioxidant defensive mechanisms, and metal absorption enrichment pathways. Notably, the interactions between SA and other plant hormones, especially IAA and JA, played a central role in these processes. These findings offer us a comprehensive perspective on understanding how to enhance the growth and heavy metal absorption capabilities of hyperaccumulator plants by regulating plant hormones, providing invaluable strategies for future environmental remediation efforts.

Biosynthesis, distribution, nutritional and organoleptic properties of bitter compounds in fruit and vegetables

Compounds that confer a bitter taste on fruits and vegetables (FAVs) play crucial roles in both plant defense and health promotion. This review details the current knowledge of the distribution, properties (toxicity, pharmacological effects and receptors) and environmental plant responses relating to the biosynthesis, catabolism and transcriptional regulation of 53 bitter plant metabolites in diverse species of FAVs. Some bitter compounds, such as flavonoids, are common in all plant species and make a minor contribution to bitter flavor, but many are synthesized only in specific taxa. They make major contributions to the bitter taste of the corresponding species and some also have significant pharmacological effects. Levels of bitter metabolites are genetically determined, but various environmental cues can affect their final concentration during preharvest development and postharvest storage processes. Molecular approaches are helping to unravel the mechanisms of biosynthesis and regulation of bitter compounds in diverse crop species. This review not only discusses the theoretical basis for utilizing breeding programs and other agricultural technologies to produce FAVs with improved safety, favorable taste and healthier profiles, but also suggests new directions for the utilization of bitter compounds in FAVs for the development of natural pesticides and health-promoting medicines.

Bridging the Gaps between Plant and Human Health: A Systematic Review of Soyasaponins

Saponins, prominent secondary plant metabolites, are recognized for their roles in plant defense and medicinal benefits. Soyasaponins, commonly derived from legumes, are a class of triterpenoid saponins that demonstrate significant potential for plant and human health applications. Previous research and reviews largely emphasize human health effects of soyasaponins. However, the biological effects of soyasaponins and their implications for plants in the context of human health have not been well-discussed. This review provides comprehensive discussions on the biological roles of soyasaponins in plant defense and rhizosphere microbial interactions; biosynthetic regulation and compound production; immunological effects and potential for therapeutics; and soyasaponin acquisition attributed to processing effects, bioavailability, and biotransformation processes based on recent soyasaponin research. Given the multifaceted biological effects elicited by soyasaponins, further research warrants an integrated approach to understand molecular mechanisms of regulations in their production as well as their applications in plant and human health.

Identification of quantitative trait loci associated with soyasaponin I concentration in soybean seed

Key message Significant QTL for soyasaponin I, as the major component of the soyasaponin B, have been identified using an RIL soybean population, which could facilitate the development of functional food soybean cultivars. Soyasaponin B forms that are naturally found in soybean (Glycine max [L.] Merr.) seed, have been of interest to the food industry because of their functional food properties. The predominant form soyasaponin B is soyasaponin I. While some of the genes in the biosynthesis of soyasaponins have been characterized, the underlying genetics of soyasaponins as a quantitative trait is still poorly understood. The objective of this study was to identify quantitative trait loci (QTL) associated with the accumulation of soyasaponin I using a genetic mapping population. The population consisting of 186 F4:7 recombinant inbred lines derived from the cross of 'OAC Glencoe' and 'OAC Wallace' was grown in two Southern Ontario locations in 2015 and 2016. The concentration of soyasaponin I was determined using high-performance liquid chromatography. Putative QTL associated with the accumulation of soyasaponin I were identified through simple interval mapping and composite interval mapping on chromosomes 10 and 16, which explained up to 11% of the total phenotypic variation per QTL for the trait. A significant positive correlation was observed between soyasaponin I and seed protein concentration in the mapping population, which may be advantageous for the development of soybean lines with improved soyasaponin I profiles. QTL identified in this study may facilitate marker-assisted selection for the development of food-grade soybean lines with improved functional properties.

Identification of environmentally stable QTLs controlling Saponin content in Glycine max

Saponins are secondary metabolites that are widely distributed in plants. There are two major saponin precursors in soybean: soyasapogenol A, contributing to the undesirable taste, and soyasapogenol B, some of which have health benefits. It is important to control the ratio and content of the two major saponin groups to enhance the appeal of soybean as a health food. The structural diversity of saponin in the sugar chain composition makes it hard to quantify the saponin content. We measured the saponin content in soybean by removing the sugar chain from the saponin using acidic hydrolysis and detected novel quantitative trait loci (QTLs) for saponin content. Major QTLs in the hypocotyl were identified on chromosome 5 near the SSR marker, Satt 384, while those in the cotyledon were on chromosome 6 near Sat_312, which is linked to the T and E1 loci. Our results suggest that saponin contents in the hypocotyl and cotyledon are controlled by different genes and that it is difficult to increase the beneficial group B saponin and to decrease the undesirable group A saponin at the same time.