The Arabidopsis tandem zinc finger protein AtTZF1 affects ABA- and GA-mediated growth, stress and gene expression responses.

摘要: Tandem zinc finger (TZF) proteins are characterized by two zinc-binding CCCH motifs arranged in tandem. Human TZFs such as tristetraproline (TTP) bind to and trigger the degradation of mRNAs encoding cytokines various regulators. Although molecular functions plant unknown, recent genetic studies have revealed roles hormone-mediated growth environmental responses, well regulation gene expression. Here we show that expression AtTZF1 (AtCTH/AtC3H23) mRNA is repressed a hexokinase-dependent sugar signaling pathway. However, acts positive regulator ABA/sugar responses negative GA at least part modulating RNAi AtTZF1-3 caused early germination slightly stress-sensitive phenotypes, whereas plants over-expressing were compact, late flowering stress-tolerant. The developmental phenotypes only partially rescued exogenous application GA, implying reduction response or defects other mechanisms. Likewise, enhanced cold drought tolerance not associated with increased ABA accumulation, suggesting it mainly affected. Consistent this notion, microarray analysis showed over-expression mimics effects deficiency on Notably, network centered GA-inducible ABA/sugar-repressible putative peptide hormone encoded GASA6 was severely over-expression. Hence may serve connecting sugar, ABA, responses.