Evaluation of the expression of some genes affecting flowers pollination and fertilization in the date palm cv. Barhee, propagated by tissue culture and offshoot

Offshoot planting is the most common way of propagating date palms. Due to the limitation of the number of offshoots produced by each palm tree and the problems with their transferring and planting, the tissue culture technique is recommended for palm propagation. Tissue culture plantlets are completely similar to the mother stock. But in some cases (like as date palm cv. Barhee) this method shows somaclonal variation, such as abnormalities in pollination and fertility. Gene expression analysis can determine the molecular mechanism of somaclonal variation. Therefore, in this research, we investigated the expression of some genes affecting date palm pollination and fertilization, including Ubiquitin (UBQ), Metallothionein (MT), Phosphofructokinase (PFK), and Polyadenylate binding (PABP), in the Barhee cultivar at three stages of the inflorescence spathe growth (15, 25, and 35 cm long) with three replicates. The transcription amplification results showed that there was a significant difference in the mutual effects of spathe growth stages and propagation methods on gene expression. The expression levels of PFK and PABP were 1.6 and 1.3 times respectively, in tissue culture propagated palms comparing to offshoot propagated palms only at the initial stage of spot growth. However, the expression level of UBQ and MT genes was lower in tissue culture palms than in offshoot palms in all stages of spathe growth. We also investigated the protein network interacting with MT and found a relationship and interaction of this protein with proteins effective in male sterility and seed development.