Abstract
Background The spotted lanternfly (SLF), Lycorma delicatula , is a polyphagous invasive species in the United States known for causing significant damage to grapevines. This phloem-feeding insect secretes saliva containing effector proteins at the time of feeding, allowing for the ingestion of the phloem’s nutrients. The mechanisms that SLF uses to modulate plant defenses and feed efficiently remain unknown and understudied. Methods and Results: We identified LdEP01, an SLF predicted secreted effector protein with a FK506 binding protein (FKBP)-type domain and two EF-hand Ca 2+ binding domains. LdEP01 is highly expressed in the salivary glands compared to the SLF’s full body. LdEP01 modulates plant defenses by suppressing cytosolic calcium accumulation and suppressing hypersensitive response (HR). Functional analysis confirmed that LdEP01 binds to calcium but does not undergo conformational change when bound to calcium. Conclusions: These findings suggest that LdEP01 plays a crucial role in modulating plant defenses, allowing SLF to feed efficiently on plants.