Seven zinc-finger transcription factors are novel regulators of the stress responsive gene OsDREB1B

Abstract

Plants have evolved several mechanisms in order to cope with adverse environmental conditions. The transcription factors (TFs) belonging to the DREB1/CBF subfamily have been described as major regulators of the plant responses to different abiotic stresses. This study focused on the rice gene OsDREB1B, initially described as highly and specifically induced by cold. However, here it is shown that OsDREB1B is not only induced by low temperatures, but also by drought and mechanical stress. In order to identify novel TFs that bind to its promoter, a yeast one-hybrid system was used to screen a cold-induced cDNA expression library. Thereby seven novel Zn-finger TFs were identified that bind to the promoter of OsDREB1B. Among them, there were four Zn-finger homeodomain (ZF-HD) and three C(2)H(2)-type Zn-finger TFs. Gene expression studies showed that these TFs are differentially regulated at transcriptional level by different abiotic stress conditions, which is illustrative of the crosstalk between stress signalling pathways. Protein-protein interaction studies revealed the formation of homo- and heterodimers among the ZF-HD TFs identified, but not for the C(2)H(2)-type. Using a transactivation assay in Arabidopsis protoplasts, all the TFs identified repressed the expression of the reporter gene, driven by the promoter of OsDREB1B. This assay also showed that the dimerization observed between the ZF-HD TFs may play a role on their transactivation activity. The results here presented suggest a prominent role of Zn-finger TFs in the regulation of OsDREB1B.

Molecular cloning and expression analysis of zinc finger-homeodomain transcription factor TaZFHD1 in wheat

“…ZFHD TFs have been isolated from several plant species, including Arabidopsis (Tan and Irish, 2006), Flaveria trinervia (Windhövel et al, 2001), soybean (Park et al, 2007), and rice (Figueiredo et al, 2012). Based on the reported nucleotide sequences of ZFHD from rice and maize, a cDNA clone encoding ZFHD protein was isolated from wheat using RT-PCR.…”

“…ABA was found to enhance the expression of ZFHD4 and ZFHD8 from rice (Figueiredo et al, 2012), both genes were also induced by drought conditions. Arabidopsis ZFHD1 gene was upregulated in response to ABA treatment and was shown to enhance drought tolerance when overexpressed in transgenic plants (Tran et al, 2007).…”

“…Arabidopsis ZFHD1 gene was upregulated in response to ABA treatment and was shown to enhance drought tolerance when overexpressed in transgenic plants (Tran et al, 2007). Previous studies have shown that the expression of ZFHD genes are induced by different kinds of stresses (Park et al, 2007;Tran et al, 2007;Jain et al, 2008;deDeus Barbosa et al, 2009;Figueiredo et al, 2012).…”

Novel Zinc Finger-Homeodomain Gene from Barley (HvZFHD1) is Differentially Regulated During Spike Development and under Hormonal Treatments and Abiotic Stresses

“…ZFHDs have been identified and characterized in many plants, such as Arabidopsis thaliana, Oryza sativa, Glycine max, and Triticum aestivum (Park et al, 2007;Hong et al, 2011;Figueiredo et al, 2012;Abu-Romman, 2014). The Arabidopsis genome has 14 ZFHD genes that have unique biochemical activities.…”

Zinc deficiency affects physiological and anatomical characteristics in maize leaves

“…Zinc plays a key role as a structural constituent and regulatory co-factor in a wide range of enzymes and proteins (Broadley et al, 2007;Hänsch and Mendel, 2009;Figueiredo et al, 2012). The vast majority of plant enzymes that are activated by Zn are involved in carbohydrate metabolism, maintenance of cell membrane integrity, protein synthesis and in the regulation of auxin synthesis (Skoog, 1940;Coleman, 1992).…”