Magnesium Application Improves 2-Acetyl-1-Pyrroline Biosynthesis and Overall Quality Properties in Fragrant Rice

Rice is a vital crop worldwide, with fragrant rice standing out for its exceptional cooking properties and aromatic allure. 2-acetyl-1-pyrroline (2-AP) contributes to this unique aroma as a key compound and target for breeding and cultivation. Magnesium (Mg) plays fundamental roles in plant photosynthesis, metabolism, and production. However, the impact of magnesium application on 2-AP biosynthesis and yield of aromatic rice remains largely unclear. In a two-year field experiment, we applied foliar Mg at three concentrations (Mg1, Mg2, and Mg3 with 1%, 2%, and 3% MgCl₂ solutions, respectively) and observed significant enhancements in fragrant rice grain yield, with 1% MgCl₂ and 2% MgCl₂ treatments being the most effective. These treatments also increased grain protein content, Mg levels, brown rice percentage, and head rice percentage, while reducing grain amylose content. Importantly, 1% MgCl₂ and 2% MgCl₂ treatments enhanced the activities of key enzymes involved in 2-AP biosynthesis. Our study recommends Mg1 and Mg2 as optimal concentrations for foliar Mg application in fragrant rice production towards simultaneous improvement of yield, quality, and aroma.

Schematic diagram illustrating regulation of quality and yield of rice under foliar Mg application.