Abstract
The isoflavone profiles of seeds of various soybean genotypes with different levels of shade tolerance at the seedling stage were investigated. High-performance liquid chromatography (HPLC) was used to quantify 12 isoflavones, and the data were analyzed using a multivariate statistical analysis. Combined with field experimental data and an orthogonal partial least-squares discriminant analysis (OPLS-DA), several aglycones (genistein (GE), daidzein (DE), and glycitein (GLE)) were selected and identified as key compounds involved in the shade tolerance of soybean seedlings. Additional correlation analysis and laboratory shading stress experiments with soybean seedlings also confirmed the function of these selected isoflavones, especially GE, in the discrimination of soybean seedlings with different levels of shade tolerance. Furthermore, the structure–antioxidant activity relationships between a range of isoflavones and the plant shade-tolerance mechanism are discussed. Targeted metabolomic analyses of isoflavones could reveal the diversity of shade tolerance in soybean seedlings, thus contributing to the breeding of excellent soybean varieties.
Highlights
Multi-species cropping is an ecological planting pattern that provides a more favorable environment for enhancing the land utilization ratio, especially in developing countries
Weighted index of sensitivity (WIS) values were calculated based on various agronomic characteristics according to the sensitivity of the soybean seedlings to shade generated by the intercropped maize
The current evaluation method was conducted based on a real field experiment, which can take a long time[14], especially when testing numerous germplasm types
Summary
Multi-species cropping is an ecological planting pattern that provides a more favorable environment for enhancing the land utilization ratio, especially in developing countries. Under optimum bandwidth and narrow-row spacing in maize, total intercrop yields were higher than the sole-cropped maize and soybean, and the land equivalent ratios of the intercropping systems were higher than 1.312 Another main strategy is the selection of suitable varieties, which consists of two sub-components: compact maize and shade-tolerant soybean. Previous research revealed that the combination of compact maize with the appropriate distance between maize and soybean rows improved the photosynthetically active radiation (PAR) intensity and transmittance in maize-soybean relay strip intercropping systems. Previous findings indicate that isoflavonoid metabolism plays an important role in plant stress resistance responses It is not clear whether there is a positive relationship between the isoflavonoid profile and shade tolerance in soybeans. The orthogonal partial least-squares discriminant analysis (OPLS-DA) technique was used to obtain robust and clear classification models and to identify the key compounds involved in the shade tolerance of soybean seedlings[15]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
