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Defense Responses of Nicotiana benthamiana 14‐3‐3 Genes in Virus‐Induced Effector‐Triggered Immunity
Author(s) -
Spencer Jennifer,
Sobhanian Soha,
Sacco Melanie
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.887.12
Subject(s) - nicotiana benthamiana , biology , epitope , effector , immune receptor , immune system , innate immune system , microbiology and biotechnology , receptor , virus , virology , biochemistry , genetics , antibody
Plants possess multiple tiers of immunity, the most specific involving immune receptors that provide effector‐triggered immunity (ETI). ETI is often associated with hypersensitive response (HR), a type of programmed cell death. The 14‐3‐3 gene family is conserved across eukaryotes and acts in myriad cellular processes, including plant immunity. We identified a Nicotiana benthamiana 14‐3‐3 isoform that interacted with the immune receptor Tm2‐2 from Solanum lycopersicum using an HA epitope‐tagged amino‐terminal Tm2‐2 fragment by affinity purification and tandem mass spectrometry. Tm2‐2 confers resistance against Tobacco mosaic virus by recognition of the virus 30K movement protein (MP) and elicitation of defenses, including HR. Interaction between 14‐3‐3 proteins and Tm2‐2 was verified by co‐immunoprecipation with Flag epitope‐tagged 14‐3‐3 proteins co‐expressed with the HA‐tagged Tm2‐2 amino‐terminal domain in N. benthamiana . Chemical inhibition of 14‐3‐3 activity in N. benthamiana using 5‐aminoimidazole‐4‐carboxamide 1‐β‐D‐ribofuranoside (AICAR) resulted in delayed onset and reduced development of HR‐like cell death in leaves transiently co‐expressing MP and full‐length Tm2‐2 by Agrobacterium tumefaciens infiltration. This observation supports a biological function for the Tm2‐2 and 14‐3‐3 interaction detected by affinity co‐purification. Furthermore, HR elicited by the unrelated immune receptor Bs2 from Capsicum anuum in the presence of the bacterial protein AvrBs2 from Xanthomonas campestris was also diminished by AICAR treatment. These results indicate that 14‐3‐3 proteins play a role in Tm2‐2‐ and Bs2‐mediated signaling and may act as a common facilitator for immune receptor signaling in the plant family Solanaceae.