Search

Class A saponins are responsible for the taste of soybean products, and the rapid identification of class A saponins from soybean food is essential for both food safety and cultivar screening. In this study, we propose a colorimetric assay based on the coupling of gap ligase chain reaction (Gap-LCR) with DNAzyme to detect the target GmSg-1genes of class A soybean saponins with the naked eye, without the involvement of expensive instruments. The limits of detection (LODs) for the GmSg-1aand GmSg-1bgenes were determined to be 0.1618 and 0.1625 μM, respectively, with a linear range of 0.2–1.2 μM. The DNAzyme-based Gap LCR assay was successfully employed to identify the target genes from different soybean cultivars, providing a simple means for monitoring the quality of soybean products.

The additive and epistatic effects and their genotype × environment (GE) effects on percentage gain with physiological traits under different environments were analyzed in soybean. The genetic characters of physiological traits in soybean and characters of quantitative trait loci (QTL) detected in different environments are discussed. A backcross inbred line (BIL) population of soybean derived from the cross of strong drought tolerant wild soybean, “SNWS0048” as a recipient parent and drought-sensitive variety “Jinda73” as a donor parent was examined to identify the QTL and epistatic QTL and GE effects on drought-tolerant physiological traits in Shanxi, China, in 2008 and 2010. Six QTLs with additive (a) effects and/or additive × environment interaction (ae) effects and three pairs of QTLs with additive × epistatic main (aa) and/or epistasis × environment interaction (aae) effects were detected in different water environment over two years. Six QTLs with aeffects and/or aeeffects were mapped to linkage groups D2, G, M and N. Among them, there were two QTLs without aeeffects, one with aeeffects in all four environments, two QTLs with aeeffects in two environments and one QTL with aeeffects in only one environment. Among three pairs of QTLs, one pair was identified with aaeffect and aaeeffect, one pair only exhibited aaeffect, and one pair only had aaeeffect without aaeffect. These indicated that different water environments could affect the expression of genes relevant to drought tolerant traits.

In-situ monitoring of pesticide residues during crop growth or/and in related products is of great significance in avoiding the abuse of pesticides but remains challenging thus far. In this report, we proposed a background-free surface-enhanced Raman spectroscopy (bf-SERS) platform to non-destructively track the nitrile-bearing pesticide residues in soybean leaves with high sensitivity and selectivity. The outstanding feature of the assay stems from the dramatic Raman enhancement effect of the 50 nm-sized gold nanoparticles (AuNPs) towards the pesticides and simultaneously the background-free Raman signal of the nitrile group in the so-called Raman-silent region (1800-2800 cm‒1). This bf-SERS assay was applied to evaluate the penetration effects of nitrile-bearing pesticides and monitor their residues in soybean leaves after rinsing with various solutions, providing a reliable tool for guiding the safe use of nitrile-bearing pesticides in agriculture.