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

Saeid ABU-ROMMAN,Khaldoun AL-HADID

doi:10.15835/nbha45110612

Abstract

Plant zinc finger-homeodomains (ZFHDs) are transcriptional factors that play an important role in regulating plant growth and development. Several ZFHD genes were cloned and characterized in many plant species. In the present study, a full-length cDNA sequence of ZFHD gene was cloned from barley (termed as HvZFHD1) using reverse transcription polymerase chain reaction (RT-PCR). The sequence analysis showed that the HvZFHD1 was 1477 bp in length, and contained a complete open reading frame (ORF) of 1161 bp. The deduced protein is composed of 386 amino acids, with a predicted molecular weight of 40.46 kDa and a theoretical isoelectric point of 8.5. Multiple sequence alignment indicated that HvZFHD1 protein shared high identity with ZFHD proteins from wheat, maize, and rice. The predicted HvZFHD1 protein contained the characteristic putative zinc finger domain in the N-terminus and a DNA binding homeodomain in the C-terminus. The expression level of HvZFHD1 was investigated using qRT-PCR during spike development and in response to exogenous phytohormones and abiotic stresses. The results showed that the expression level of HvZFHD1 was fluctuated during spike development with higher expression during anthesis, medium milk, late milk, and early dough stages. The expression of barley ZFHD1 was strongly responsive to abscisic acid treatment and was up-regulated in seedlings treated with methyl jasmonate, salicylic acid, and ethephone. In addition, the expression levels of HvZFHD1 were increased by dehydration, salinity, and heat stress, but not affected by cold stress. The expression patterns of HvZFHD1 suggest that it might play a role in flowering and flower development and is involved in plant responses to abiotic stresses.

Highlights

Zinc finger” is a term applied to a diverse set of protein motifs that commonly binds to zinc ions (Klug and Schwabe, 1995)
C2H2, C2C2 and C3H zinc fingers interact with one zinc ion, whereas the RING, PHD, and LIM zinc fingers interact with two zinc ions (Hu et al, 2008)
About 176 zinc finger proteins of C2H2-type were reported in the Arabidopsis genome, many of which of this type of zinc finger protein function as transcriptional factors (Fujita et al, 2011)

Summary

Introduction

Zinc finger” is a term applied to a diverse set of protein motifs that commonly binds to zinc ions (Klug and Schwabe, 1995). These motifs were called “zinc fingers” because a zinc atom is coordinated by cysteines and/or histidines to form the finger-like structures required for their specific functions (Takatsuji, 1998). Zinc fingers have broad range of functions in metabolism, signaling, transcription, translation, replication, repair, proliferation and apoptosis (Krishna et al, 2003). Zinc fingers can bind to a variety of compounds, such as proteins, nucleic acid, and small molecules (Krishna et al, 2003).

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