Uncovering Herbivory Defense Responsive Proteins in Chickpea (Cicer spp.) Through Mass Spectrometry-Based Proteomics

The legume pod borer, Helicoverpa armigera, is a major biotic constraint to chickpea production, causing substantial global yield losses. The downstream signaling pathways underlying host-insect interactions remain largely unexplored, yet understanding these processes is crucial for developing pest-resilient cultivars.

A systems biology approach was employed to investigate the leaf proteome of 2 cultivated chickpea genotypes (JG 12 and JG 36) and 1 moderately tolerant wild genotype (ILWC 46) under simulated herbivory. This study aimed to elucidate molecular mechanisms underlying plant defense against insect attack.

Proteomic profiling revealed 190-200, 170-210, and 170-200 total protein spots in ILWC 46, JG12, and JG 36, respectively. 76 Differentially Expressed Proteins (DEPs) were visually identified, of which 62 were selected for Mass Spectrometric (MS) analysis. ILWC 46 exhibited 22 DEPs (4 downregulated, 18 upregulated), JG 12 showed 23 DEPs (5 downregulated, 18 upregulated), and JG 36 had 17 DEPs (10 downregulated, 7 upregulated). Five proteins were common to JG 12 and JG 36.

Genotype-specific proteomic changes suggest variable defense responses: predominant upregulation in ILWC 46 indicates enhanced metabolic activity under stress, whereas JG 36's downregulation implies reduced adaptability. Functional categorization showed modulation of photosynthesis, primary metabolism, and stress-related proteins, highlighting energy reallocation and activation of defense pathways sustaining stress tolerance differences among genotypes.

This study provides a comprehensive proteomic perspective on chickpea defense responses to herbivory, highlighting candidate proteins and pathways for enhancing insect resistance in both cultivated and wild germplasm.