抄録
In plants, perception of pathogen-associated molecule patterns (PAMPs) triggers innate immune responses that contribute to disease resistance. Previously, we showed that the small GTPase OsRac1 play key roles in defense signaling of rice. Overexpression of the constitutively active form of OsRac1 enhances reactive oxygen species production in rice cells treated by N-acetylchitooligosaccharide elicitor, a PAMP derived from rice blast fungus. Here we report the development of an intracellular fluorescence resonance energy transfer (FRET) sensor that can detect the activation of OsRac1 by N-acetylchitooligosaccharide elicitor in vivo . The FRET biosensor is composed of OsRac1, the CRIB domain of PAK1, which binds specifically to the GTP-bound form of Rac, and variants of the green fluorescent protein, Venus and SECFP, as FRET donor and acceptor, respectively. This biosensor would facilitate identification of the upstream regulators of OsRac1, such as guanine exchange factors (GEFs) and real-time monitoring of PAMP-induced defense responses.
