Proteomic Dynamics in the Interaction of Susceptible and Resistant Tomato Cultivars and Potato Cyst Nematodes.

Abstract

This study investigates the proteomic dynamics in tomato cultivars with differing resistance to potato cyst nematodes (PCNs). Cyst-forming nematodes, significant agricultural pests, induce complex molecular responses in host plants, forming syncytia in roots for their nutrition. This research employs mass spectrometry to analyze the proteomes of infected and uninfected roots from susceptible (Moneymaker) and resistant (LA1792 and L10) tomato lines. Over 2800 high-confidence protein hits were identified, revealing significant differences in abundance between susceptible and resistant lines. Notably, resistant lines exhibited a higher number of newly expressed proteins compared to susceptible lines; however, the proportion of induced and suppressed proteins was strongly genotype-dependent. Gene ontology (GO) analysis highlighted that nematode infection in susceptible line significantly regulates many defense-related proteins, particularly those involved in oxidative stress, with a similar number being upregulated and downregulated. Some GO terms enriched among nematode-regulated proteins also indicate the involvement of programmed cell death (PCD)-related processes. The susceptible line exhibited a prevalence of downregulated proteins, among which defense associated GO terms were significantly overrepresented. Four proteins (APY2, NIA2, GABA-T, and AATP1) potentially crucial for nematode parasitism were identified and their Arabidopsis orthologs were studied. Mutant Arabidopsis lines showed altered nematode resistance, supporting the involvement of these proteins in plant defense. This study highlights the complexity of host-nematode interactions and emphasizes the importance of proteomic analyses in identifying key factors and understanding plant defense mechanisms.