The selenium-promoted daidzein production contributes to its induced nodulation in soybean plants

Authors: SILVA, VINICIUS - Cornell University; LUI, ANDY - Cornell University; CARVALHO, MARIANA - Cornell University; NAMORATO, FILIPE - Cornell University; FEI, ZHANGJUN - US Department Of Agriculture (USDA); REIS, ANDRE - Universidad De Sao Paulo; Liu, Jiping; VATAMANIUK, OLENA - Cornell University; Li, Li

Submitted to: Environmental and Experimental Botany
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/2/2023
Publication Date: 12/9/2023
Citation: Silva, V., Lui, A., Carvalho, M., Namorato, F., Fei, Z., Reis, A., Liu, J., Vatamaniuk, O., Li, L. 2023. The selenium-promoted daidzein production contributes to its induced nodulation in soybean plants. Environmental and Experimental Botany. Vol. 218, 105591. https://doi.org/10.1016/j.envexpbot.2023.105591.
DOI: https://doi.org/10.1016/j.envexpbot.2023.105591

Interpretive Summary: Selenium (Se) deficiency is a serious problem in the world and Se biofortification in crops provides an effective means to enhance dietary Se intake. In this study, we found that in addition to providing the essential Se nutrient, Se treatment greatly increases root nodule number and nodule fresh weight. The stimulation effects were found to be associated with Se-induced increase of isoflavone daidzein production in nodules and roots. Exogenous supply of daidzein documents its effectiveness in promoting nodulation. In addition, we observed Se treatment enhances total sugar level and the total N-compounds. Transcriptome analysis reveals differentially expressed genes involved in the Se-induced nodulation. Our findings uncover an important role of Se in plant growth and development and provide insights underlying the Se-induced nodulation in soybean plants.

Technical Abstract: Selenium (Se) is an essential micronutrient to humans. Se biofortification in crops provides an effective means to enhance dietary Se intake. However, the effects of Se treatment on plant growth and development remain to be fully studied. In this study, we applied Se to soybean plants grown hydroponically and in soil. We observed that selenate treatment increased nodule number and fresh weight. Se supply was found to greatly increase isoflavone daidzein accumulation in roots and nodules. Furthermore, exogenous supply of daidzein but not kaempferol significantly increased nodule number and fresh weight, suggesting a specific role of daidzein accumulation in the Se-induced nodulation in soybean plants. In addition, the total sugar levels in nodules, roots, and leaves were significantly enhanced following selenate treatment. Subsequently, the N-compounds were greatly increased after Se treatment in all tissues examined. Transcriptome analysis revealed that Se treatment altered various metabolic and cellular processes to affect nodulation and nodule development. Se treatment upregulated GmNIN2b, an important nodule organogenesis gene, as well as genes associated with sugar metabolism and ureide transport. Our study provides insights underlying the Se-induced nodulation in soybean plants and further documents that Se biofortification in soybean can simultaneously improve not only the essential nutrient content but also nodulation for biological nitrogen fixation, a critically important agronomic trait in soybean plants.