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

ABSTRACT: The H subunit of Mg-chelatase (CHLH) was shown to regulate abscisic acid (ABA) signaling and the I subunit (CHLI) was also reported to modulate ABA signaling in guard cells. However, it remains essentially unknown whether and how the Mg-chelatase-catalyzed Mg-protoporphyrin IX-production differs from ABA signaling. Using a newly-developed surface plasmon resonance system, we showed that ABA binds to CHLH, but not to the other Mg-chelatase components/subunits CHLI, CHLD (D subunit) and GUN4. A new rtl1 mutant allele of the CHLH gene in Arabidopsis thaliana showed ABA-insensitive phenotypes in both stomatal movement and seed germination. Upregulation of CHLI1 resulted in ABA hypersensitivity in seed germination, while downregulation of CHLI conferred ABA insensitivity in stomatal response in

SUBMITTER: Du SY 

PROVIDER: S-EPMC3472068 | biostudies-literature | 2012 Nov

REPOSITORIES: biostudies-literature