Metabolic profiling of Oryza sativa seedlings under chilling stress using nanoliter electrospray ionization mass spectrometry

Low temperatures significantly impact on rice ( Oryza sativa ) yield and quality. Traditional metabolomic techniques, often involving time-consuming chromatography-mass spectrometry procedures, are currently in use. This study investigated metabolomic responses of rice seedlings under low-temperature stress using nanoliter electrospray ionization mass spectrometry (nanoESI-MS) in combination with multivariate analysis . Results revealed distinct metabolic profiles in ‘Qiutianxiaoting’ ( japonica ) and ‘93-11′ ( indica ) rice seedlings. Among the 36 identified compounds in rice, seven key metabolites, comprising l -glutamic acid, asparagine, tryptophan, citric acid, α-linolenic acid, malic acid, and inositol, were identified as responsive to cold stress. Notably, malic acid content reached 1332.40 μg/g dry weight in Qiutianxiaoting and 1444.13 μg/g in 93-11. Both the qualitative and quantitative results of nanoESI-MS were further confirmed through gas chromatography-mass spectrometry validation. The findings highlight the potential of nanoESI-MS for rapidly characterizing crucial metabolites across diverse plant species under exposure to stress.