Studying Expression Changes of Genes Involved in Direct Regeneration Pathway in Piarom Dates

Abstract

Date palm (Phoenix dactylifera L) as a monocotyledonous plant of the Palmaceae family are one of the most important economic and strategic products in southern of Iran. Accordingly, in this study, direct branching was investigated to prevent possible abnormalities of indirect proliferation using embryogenic callus. The expression of genes involved in regeneration were investigated between mother plant, one-year-old offshoot attached to mother, and seedlings developed by tissue culture and one-year-old micro-samples in a glass. These samples were investigated using two target genes compared to the control gene beta actin. They were studied in Murashige and Skoog (MS) medium with differential hormonal combinations of IAA, Zeatin, 2IP, BAP, and NAA. The best hormonal treatment compound that led to branching was 3 mg/L of IAA, 4mg/L of Kin, and 4 mg/L of Zeatin. For studying the relationships in controlling changes of expression genes involved in regeneration process of leaf samples in mother plant isolated from offshoot, 3-year-old offshoot leaves still connected to the mother plant, and the regenerated and non-regenerated subsamples were evaluated in the presence of proton symporter DUR3 and XTH genes. The results of assessing gene expression showed an increase in expression of both DUR3 and XTH genes. XTH gene was equally expressed as beta actin gene and DUR3 gene was expressed two times more than the control gene in the regenerated subsample. Since, the regenerated sample was considered an immature sample; expression of these genes was lower than adult sections. Expression of the genes was decreased in the non-regenerated embryo sample (XTH gene was expressed by 5.5 unit and DUR3 gene was expressed by 062 unit) showing that this degeneration had higher efficiency in plants regeneration growth stages. Considering the direct regeneration can probably prevent abnormalities caused by tissue culture, and two genes (DUR3 and XTH) in the synthesis pathway make the same compounds that play a controlling role in increasing and reducing expression on each other.