An N-terminal region of a Myb-like protein is involved in its intracellular localization and activation of a gibberellin-inducible proteinase gene in germinated rice seeds

Abstract

The expression of the gene for a proteinase (Rep1) is upregulated by gibberellins. The CAACTC regulatory element (CARE) of the Rep1 promoter is involved in the gibberellin response. We isolated a cDNA for a CARE-binding protein containing a Myb domain in its carboxyl-terminal region and designated the gene Carboxyl-terminal Myb1 (CTMyb1). This gene encodes two polypeptides of two distinctive lengths, CTMyb1L and CTMyb1S, which include or exclude 213 N-terminal amino acid residues, respectively. CTMyb1S transactivated the Rep1 promoter in the presence of OsGAMyb, but not CTMyb1L. We observed an interaction between CTMyb1S and the rice prolamin box-binding factor (RPBF). A bimolecular fluorescence complex analysis detected the CTMyb1S and RPBF complex in the nucleus, but not the CTMyb1L and RPBF complex. The results suggest that the arrangement of the transfactors is involved in gibberellin-inducible expression of Rep1.

Magnaporthe oryzae Induces the Expression of a MicroRNA to Suppress the Immune Response in Rice

“…Taken together, we concluded that OsTCP21 and OsGAmyb are 224 authentic target genes of miR319. OsGAmyb is a transcription factor involved in many 225 developmental processes, such as regulating the expression of α-amylase in the aleurone layer 226 of rice seed; it also plays a role in pollen development (Liu et al 2010, Sutoh et al 2015. By 227 contrast, OsTCP21 function is related to rice responses to biotic and abiotic stresses.…”