Phytochemical profiling of soybean genotypes using GC/MS and UHPLC/DAD-MS

Authors: Li, Shuxian; Wang, Mei; LEE, JOSEPH - University Of Mississippi

Submitted to: PLOS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/7/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: Soybean is one of the most economically important crops worldwide. However, soybean yield can be substantially decreased by many diseases. Soybean lines could have different reactions to pathogen infection. As a first step toward investigating the biochemical basis of soybean resistance and susceptibility to diseases, plant chemicals in the seeds of 52 soybean lines with different reactions to soybean diseases of soybean rust, Phomopsis seed decay, and purple seed stain, were analyzed. A total of 46 compounds were tentatively identified which included 11 chemical groups. Compounds having reported antioxidant, anti-microbial, and anti-inflammatory activities were identified. Compounds known as isoflavones have been reported to play an important role in defense from plant pathogens. Although there was variation in the isoflavone content among soybean lines, those with the soybean rust resistance Rpp6 gene (lines PI 567102B, PI 567104B, and PI 567129) consistently exhibited the highest concentrations of certain types of isoflavone. Two soybean rust resistant lines, PI 230970 and PI 200456, possessed unique isoflavone compounds. Results of this study provide useful information for further investigation of the biochemical basis of soybean resistance to soybean rust. The results may also aid in selection of soybean lines for breeding for resistance to soybean rust and other diseases.

Technical Abstract: Soybean is one of the most economically important crops worldwide. However, soybean yield can be substantially decreased by many diseases. Soybean genotypes could have different reactions to pathogen infection. As a first step toward investigating the biochemical basis of soybean resistance and susceptibility to disease, phytochemicals in the seeds of 52 soybean genotypes previously reported to have different reactions to diseases of soybean rust (SBR), Phomopsis seed decay (PSD), and purple seed stain (PSS) were analyzed. Using GC/MS, a total of 46 compounds were tentatively identified which included 11 chemical groups. Among those, the major group was esters, followed by carboxylic acid, ketone, and sugar moieties. Compounds having reported antioxidant, anti-microbial, and anti-inflammatory activities were also identified. UHPLC/DAD-MS analysis indicated that there were five major isoflavone components, including daidzin, glycitin, genistin, malonyldaidzin, and malonylglycitin. Isoflavones have been reported to play an important role in defense from plant pathogens. Although there was variation in the isoflavone content among soybean genotypes, those with the SBR resistance Rpp6 gene (PI 567102B, PI 567104B, PI 567129) consistently exhibited the highest concentrations of daidzin, glycitin, genistin, and malonyldaidzin. The SBR resistant genotype, PI 230970 (Rpp2) had the greatest amount of genistin. The SBR resistant genotype, PI 200456 (Rpp5) resistant genotype uniquely contained glycitein, a compound that was absent in the other 51 genotypes examined. A PSD-resistant genotype PI 424324B had near four times the amount of a plant sterol stigmasterol as PI 556625, which was susceptible to SBR, PSD, and PSS in our previous tests. Results of this study provide useful information for further investigation of the biochemical basis of soybean resistance to soybean diseases. The results may also aid in selection of soybean lines for breeding for resistance to soybean rust and other diseases.