Characteristics, all-cause healthcare resource utilisation, and costs among high-risk adults with long COVID during Omicron predominance, 2022-2023: a retrospective cohort study using UK primary care

Herbivorous insects remain a major constraint on crop productivity, with ranking among the most destructive chewing pests of grain legumes worldwide [–]. In chickpea, severe infestations can cause extensive pod and foliage damage, leading to significant economic losses for farmers []. Because repeated insecticide applications carry environmental costs and foster resistance, there is sustained interest in endogenous plant defense genes that could complement or diversify current management strategies [–]. Chitinases are attractive candidates in this context because they hydrolyze the β-1,4-linked N-acetyl-D-glucosamine polymer chitin, a key structural component of fungal cell walls and the insect peritrophic matrix [–]. Chitinase-mediated disruption of the insect gut barrier has been proposed to enhance direct anti-herbivore activity and to complement other defense strategies, including toxin stacking in transgenic systems [–]. Plant chitinases are classified primarily into the GH18 and GH19 families, which differ in sequence, structure, and catalytic architecture [–]. Both plant-derived and heterologous chitinases have been associated with improved resistance against lepidopteran pests, although the magnitude and context dependence of these effects vary across species and experimental systems [–]. In chickpea, transcriptomic studies of simulated herbivory have revealed rapid activation of hormone-responsive defense pathways [], and a recent genome-wide analysis identified 27 chitinase genes, primarily in relation to Fusarium stress []. However, that inventory was based on an earlier chickpea genome assembly and included two loci on unplaced scaffolds. As a result, the family organization under the updated RefSeq annotation and the identity of chitinases deployed during field herbivory remain insufficiently resolved. This gap is important because mechanical wounding and natural herbivory do not always elicit equivalent molecular responses, particularly when herbivore-derived cues and hormone crosstalk are involved [, –]. Chitinases from pathogenesis-related protein families are also known to respond to salicylic acid (SA), jasmonic acid (JA), and related signaling networks [–], raising the possibility that distinct chitinase subsets contribute to different phases of chickpea defense.