Asian soybean rust (ASR), caused by Phakopsora pachyrhizi , severely constrains soybean yield. Characterization of the effector candidate Phapa-4574965 was performed to elucidate virulence mechanisms. In silico analyses of the amino acid sequence revealed a conserved Gamma-Interferon–Inducible Lysosomal Thiol reductase (GILT) domain and a high-confidence 3D structural model. Comparative genomics placed Phapa-4574965 within a rust-wide cluster enriched for GILT-containing proteins. In soybean leaves, expression was induced early and peaked at 48 h post-inoculation. In Nicotiana benthamiana , Phapa-4574965 suppressed pattern-triggered immunity—reducing reactive oxygen species and callose—and blocked hypersensitive cell death triggered by Pseudomonas syringae , indicating interference with effector-triggered immunity in this heterologous system. Confocal microscopy showed predominant nuclear localization with partial cytosolic and mitochondrial signals, suggesting multi-compartment activity. Pull-down mass spectrometry from soybean leaves identified eight putative targets, including lipoxygenase, aminomethyltransferase, fructose-bisphosphatase, and proteins linked to carbohydrate metabolism and redox homeostasis. Together, these results suggest that Phapa-4574965 is a multifunctional candidate effector capable of modulating plant immune responses and host metabolic processes, supporting its potential role during soybean– P. pachyrhizi interactions and providing targets for resistance breeding and biotechnological interventions. • Phapa-4574965 suppresses PTI and ETI via early immune interference. • The effector carries a conserved oxidoreductase GILT domain. • Subcellular targeting includes nucleus, cytoplasm, and mitochondria. • Phapa-4574965 interacts with soybean proteins linked to immunity. • Gene expression peaks align with early infection in soybean leaves.
Utiyama et al. (Fri,) studied this question.