Tissue and temporal expression of im'R172 paralogs and the AP2-like target in oil palm (Elaeis guineensis Jacq.)

摘要

Oil palm is an economically important crop, and floral development is a critical process in oil palm productivity. MicroRNA172 (miR172) has been shown to be an important regulator of the APETALA2 (AP2)-like family transcription factors involved in floral timing in a number of plants and belongs to a group of highly conserved microRNA that can be identified based on sequence homology. We identified six oil palm miR172 paralogs, representing two distinct mature miR172 isoforms based on sequence identity and predicted hairpin structures and an AP2-like target, using a combination of RT-PCR cloning and bioinformatic analysis of oil palm expressed sequence tags data. Although oil palm miR172 cleavage products were detected through 5'-rapid amplification of cDNA ends, mature miR172a and the AP2-like target showed overlapping expression patterns in oil palm. Some variation in the expression of the six paralog miR172 precursors in different oil palm tissues was observed with each of the two mature isoforms showing different expression patterns during floral development. It is suggested that the expression of different miR172 precursor paralogs is tissue-specific, and for at least one mature miR172 isoform in oil palm, there may be significant cleavage of the AP2-like target.