Roles of the different components of magnesium chelatase in abscisic acid signal transduction.

摘要: The H subunit of Mg-chelatase (CHLH) was shown to regulate abscisic acid (ABA) signaling and the I (CHLI) also reported modulate ABA in guard cells. However, it remains essentially unknown whether how Mg-chelatase-catalyzed Mg-protoporphyrin IX-production differs from signaling. Using a newly-developed surface plasmon resonance system, we showed that binds CHLH, but not other components/subunits CHLI, CHLD (D subunit) GUN4. A new rtl1 mutant allele CHLH gene Arabidopsis thaliana ABA-insensitive phenotypes both stomatal movement seed germination. Upregulation CHLI1 resulted hypersensitivity germination, while downregulation CHLI conferred insensitivity response Arabidopsis. We CHLD, sensitivity tobacco (Nicotiana benthamiana). overexpression lines wild-type Both GUN4-RNA interference major responses. These findings provide clear evidence Mg-ProtoIX production is distinct signaling, giving information understand mechanism by which two cellular processes at molecular level.