Due
to their unique properties, copper-based nanopesticides are
emerging in the market. Thus, understanding their effect on crop plants
is very important. Metabolomics can capture a snapshot of cellular
metabolic responses to a stressor. We selected maize and cucumber
as model plants for exposure to different doses of Cu(OH)2 nanopesticide. GC-TOF-MS-based metabolomics was employed to determine
the metabolic responses of these two species. Results revealed significant
differences in metabolite profile changes between maize and cucumber.
Furthermore, the Cu(OH)2 nanopesticide induced metabolic
reprogramming in both species, but in different manners. In maize,
several intermediate metabolites of the glycolysis pathway and tricarboxylic
acid cycle (TCA) were up-regulated, indicating the energy metabolism
was activated. In addition, the levels of aromatic compounds (4-hydroxycinnamic
acid and 1,2,4-benzenetriol) and their precursors (phenylalanine,
tyrosine) were enhanced, indicating the activation of shikimate-phenylpropanoid
biosynthesis in maize leaves, which is an antioxidant defense-related
pathway. In cucumber, arginine and proline metabolic pathways were
the most significantly altered pathway. Both species exhibited altered
levels of fatty acids and polysaccharides, suggesting the cell membrane
and cell wall composition may change in response to Cu(OH)2 nanopesticide. Thus, metabolomics helps to deeply understand the
differential response of these plants to the same nanopesticide stressor.