Proteome‐Wide Prediction of Putative Bemisia tabaci Effector Candidates and Transient Validation of BtApe‐Mediated Suppression of Tomato Immune Responses
Archives of Insect Biochemistry and Physiology
Published online on June 30, 2026
Abstract
["Archives of Insect Biochemistry and Physiology, Volume 122, Issue 3, July 2026. ", "The workflow illustrates the process of identifying and preliminarily validating the functionality of effectors in Bemisia tabaci. The proteome of B. tabaci served as the initial input for a multiparameter effector prediction pipeline, which integrates secretory features, subcellular targeting predictions, and parallel computational tools to generate a set of candidate effectors. These candidates were subsequently classified into major functional categories, including proteases, oxidoreductases, carbohydrate‐active enzymes (CAZymes), and proteins of uncharacterized function. From this predicted set, the secretory protein BtApe was selected for further validation. BtApe was cloned and transiently expressed in plant tissue, followed by histochemical analysis of hydrogen peroxide (H2O2) and superoxide anion (O2−) accumulation using DAB and NBT staining, respectively. This workflow summarizes the progression from proteome‐wide candidate discovery to plant‐based functional screening of a selected whitefly effector candidate.\n\n\n\n\n\nABSTRACT\nPhloem‐feeding insects such as aphids, planthoppers, and whiteflies use salivary proteins to aid feeding, adapt to hosts, and manipulate plant defenses, shaping a dynamic plant‐herbivore conflict. Among them, the sweet potato whitefly, Bemisia tabaci, is a major global pest that threatens food security by causing feeding damage and transmitting plant viruses. The salivary secretory proteins of B. tabaci remain poorly characterized. We conducted a proteome‐wide hypothesis‐based screening of the B. tabaci MEAM1/B‐biotype reference proteome using secretion, membrane‐topology, localization, and effector‐likelihood filters to prioritize candidate secreted proteins. Among 1404 proteins screened in EffectorP 3.0, 884 were identified as putative effector candidates and reported as computationally predicted rather than a validated effectorome. Most of these candidates were cytoplasmic (741), with fewer following the classical extracellular secretory pathway (143). Functional annotation showed strong enrichment of proteases (cathepsin B, cathepsin L, and serine proteases) and thioredoxin‐related proteins, some of which resemble proteins implicated in feeding systems among hemipteran insects, supporting their prioritization for validation. Protein‐association analyses highlighted protease‐related candidates as central predicted network hubs. Transient validation of one prioritized candidate, BtApe, showed attenuation of chitin‐associated oxidative staining and normalized defense‐marker responses in tomato, supporting BtApe as an immune‐modulatory candidate and defining a focused framework to validate salivary gland expression and secretion, as well as loss of function effects."]