Medicago truncatulaMt-ZFP1 Encoding a Root Enhanced Zinc Finger Protein is Regulated by Cytokinin, Abscisic Acid and Jasmonate, but not Cold

Abstract

A Medicago truncatula zinc finger protein cDNA (Mt-ZFP1) was isolated from a M. truncatula seedling cDNA library using RT-PCR product as a probe. The predicted amino acid sequence of Mt-ZFP1 is over 79% similar to S-SCOF-1 from soybean, a novel cold-inducible zinc finger protein involved in cold stress signal transduction mediated by abscisic acid (ABA). The secondary structure of Mt-ZFP1 protein was almost identical to that of S-SCOF-1. Mt-ZFP1 also contained a typical C²H²-type zinc finger domain and a putative nuclear located signal. RNA gel blot hybridization demonstrated that the Mt-ZFP1 gene was actively expressed in roots, with a lower abundance in leaf and stem tissues. Cold treatment did not induce the expression of Mt-ZFP1 in either leaves and stems or roots. Exogenous application of cytokinins marginally increased the accumulation of Mt-ZFP1 mRNA, while ABA and jasmonate treatments decreased the levels of Mt-ZFP1 mRNA. DNA gel-blot analysis demonstrated that Mt-ZFP1 is present as a single copy gene in the M. truncatula genome. These data suggest that Mt-ZFP1 is a novel zinc finger protein with different physiological functions to that of S-SCOF-1. The similar cold-inducible factor like S-SCOF-1 might not exist in M. truncatula.

• Zinc finger protein
• Cold induction
• Organ-specific expression
• Medicago truncatula
• AY258140