# Foliar-Selenium-Induced Modulation of Volatile Organic Compounds in Rice Grains: A Comparative Study of Sodium Selenite and Nano-Selenium

## TL;DR

This study shows that foliar selenium treatments, especially nano-selenium, enhance volatile compounds in rice, improving aroma.

## Contribution

The study compares nano-selenium and sodium selenite effects on rice aroma compounds and identifies distinct markers for each.

## Key findings

- Nano-selenium (SeNPs) had a more pronounced effect on increasing volatile organic compounds (VOCs) than sodium selenite.
- SeNPs identified 18 VOC markers, while sodium selenite identified 7, with all 7 markers overlapping with the SeNPs set.
- Significant interaction effects were found among selenium species, rice variety, and planting year on VOCs.

## Abstract

Rice aroma is influenced by many factors, including selenium (Se) fertilizer. In this study, we investigated the effects of different Se species on the volatile organic compounds (VOCs) in three indica rice varieties over 2022 and 2023 by forliar spray. The VOCs were analyzed using HS-SPME-GC-MS. The results showed that both Se nanoparticles (SeNPs) and sodium selenite (Na2SeO3) significantly increased the contents of most VOCs in all three varieties, with SeNPs exhibiting a more pronounced effect. PCA and OPLS-DA revealed distinct clustering of the VOCs based on Se treatments and rice varieties. By variable importance in projection (VIP) analysis with FDR correction, Na2SeO3 yielded 7 markers, whereas SeNP treatment identified 18. Every marker detected under Na2SeO3 was fully encompassed within the SeNPs set. Three-factor ANOVA indicated that there are significant interaction effects among Se species, rice variety, and planting year. Additionally, the effect sizes were evaluated in the key VOCs to quantify the effect of Se species, rice variety, and planting year. The findings highlight Se fertilizers to enhance rice aroma and suggest selecting appropriate Se species and rice varieties for aroma improvement.