Revealing the Effect of Different Nitrogen Fertilizer Levels on Rice Yield through Metabolite Evaluation

Abstract

We investigated the differences in metabolites related to rice yield under different nitrogen fertilizer levels and the regulatory roles of key metabolites in metabolic pathways, in the hope of providing data support from the metabolite level for further regulation of rice yield. This study focused on the rice variety Yangchan 15002 and used non-targeted metabolomics methods to detect the metabolic products of rice leaves under three nitrogen fertilizer levels. The yield of oryza sativa plants under high nitrogen (A3: 315 kg/ha) conditions was significantly higher than that of plants under medium (A2: 270 kg/ha) and low nitrogen (A1: 180 kg/ha) conditions. The number of grains per spike in A3 was 6.53% and 18.03% greater than in A2 and A1, respectively. Furthermore, the seed setting rate and thousand-grain weight of plants subjected to A3 treatment were significantly elevated compared to those treated with A1. Thirty metabolites related to yield components were identified, among which Pipecolic Acid, Trigoncline, and (S)-2-Aceto-2-hydroxybutanoate were negatively correlated with yield. 4-methylcellulose L-glutamic acid, C5-branched dicarboxylic acid metabolism was negatively correlated with grain number per spike. Triglycerides, L-piperidine, and (S)-2-acetone-2-hydroxybutyric acid were negatively correlated with the number of grains per spike.