Identification of quality-related volatile organic compounds in legume seeds exposed to hydropriming and artificial ageing

Seed deterioration remains a major constraint in agriculture, limiting crop productivity and sustainability. While volatile organic compounds (VOCs) have been primarily studied in the context of seed ageing, little is known about VOCs emissions associated with seed priming treatments. Therefore, this work aims to identify and compare quality related VOCs in legume seeds subjected to hydropriming (HP) and artificial ageing (AA). HP, a cost-effective priming method involving water soaking and dry-back, enhances germination and stress resilience, while AA induces seed deterioration after exposure to high temperature and humidity. Using Proton Transfer Reaction - Quadrupole ion guide - Time of Flight - Mass Spectrometry (PTR-Qi-ToF-MS), VOC emissions from four legume species, including both commonly cultivated and neglected crops, were measured. A total of 395 m/z values were detected, with different emission patterns depending on treatments and accession. Among the putatively identified VOCs, 2(3H)-furanone/2(5H)-furanone (m/z 85.0266) and benzene (m/z 79.0517) were associated with low-quality AA seeds across all tested varieties. In contrast, methanethiol (m/z 49.0098), acetaldehyde (m/z 45.0328), and ethanol (m/z 47.0482) were predominantly emitted by high-quality HP seeds, suggesting their potential role as indicators of germination efficiency. However, the occurrence of these same compounds in a few accessions of both the AA and CTRL groups highlights a partial overlap between metabolic pathways triggered by priming and those associated with ageing. This overlap introduces a novel yet problematic aspect in interpreting VOC emission patterns, indicating the need for further investigation to differentiate shared and distinct metabolic responses underlying seed priming and deterioration processes.