Activation of Wheat Defense Response by Buchnera aphidicola-Derived Small Chaperone Protein GroES in Wheat Aphid Saliva

Abstract

Salivary proteins secreted by aphids during feeding play an important role in regulating the plant defense response. We used mass spectrometry to identify 155 proteins from the wheat aphid, Sitobion miscanthi, among which 44 proteins were derived from the primary symbiont, Buchnera aphidicola. GroES, which is a highly abundant molecular chaperone that binds to GroEL, was detected in saliva. In vitro injection of purified GroES protein and overexpression of GroES in wheat leaves verified that GroES induced hydrogen peroxide accumulation and callose deposition in wheat and further activated the plant salic acid and jasmonic acid defense pathways. Our findings indicate that plants may have evolved new strategies to detect aphid attack and trigger defense responses by recognizing proteins derived from B. aphidicola, which is present in almost all aphid species.

Two salivary proteins Sm10 and SmC002 from grain aphid Sitobion miscanthi modulate wheat defense and enhance aphid performance

“…The type III secretion system (T3SS) of P. fluorescens has been maturely applied to the study of the interaction model between pathogen or grain aphid effectors with wheat, and can successfully secrete candidate effectors stably into wheat leaf cells ( Li et al., 2022 ; Liu et al., 2022 ; Zhang et al., 2022 ). In this study, we did not directly demonstrate that effectors are delivered in leaf cells, but wheat leaves infiltrated with EtHAn carrying AvrRpt2 exhibited a noticeable chlorotic phenotype and H 2 O 2 production through the infiltrated region that was not observed in wheat seedlings infiltrated with EtHAn carrying an empty pEDV6 vector, the similar results with previous studies ( Yin and Hulbert, 2011 ; Cheng et al., 2017 ; Zhang et al., 2022 ), indicating that effector proteins were delivered effectively into wheat by the P. fluorescens delivery system.…”

Functional analysis of odorant-binding proteins for the parasitic host location to implicate convergent evolution between the grain aphid and its parasitoid Aphidius gifuensis

“…Given that AgifOBP6 strongly binds to EBF, it was chosen to further study the expression characteristics at the subcellular localization. Whole-mount fluorescence was performed to identify the location of AgifOBP6 in antennae according to a previous study [34,74]. Antennae from virgin female specimens were dissected under the microscope after 24 h to 36 h of the adult stage and washed twice with PBS, pH = 7.4.…”

Callose metabolism and the regulation of cell walls and plasmodesmata during plant mutualistic and pathogenic interactions

“…This suggests that plants have evolved defense strategies against aphids by recognizing effector proteins from their endosymbiotic bacteria leading to effector-triggered immunity (Q. Li et al, 2022).…”