A role for MIR828 in pineapple fruit development

Area of Science:

• Plant genetics and genomics
• Molecular biology
• Evolutionary biology

Background:

• Previous studies sequenced pineapple (Ananas comosus) and identified microRNAs (miRNAs).
• MIR828, a regulator of anthocyanin biosynthesis, was reported in various plant groups but notably absent in Poales (grasses and bromeliads).
• Pineapple var. bracteatus has red fruit, suggesting genetic regulation of pigment biosynthesis.

Purpose of the Study:

• To investigate the presence and function of MIR828 in pineapple.
• To determine MIR828's role in regulating fruit color in Ananas comosus var. bracteatus.
• To explore the evolutionary implications of MIR828 in monocot fruit development.

Main Methods:

• Bioinformatic analysis of sequenced pineapple accessions.
• Identification and characterization of MIR828 in pineapple.
• Analysis of MIR828's post-transcriptional gene silencing targets, including MYB transcription factors.

Main Results:

• MIR828 was identified in pineapple (Ananas comosus).
• MIR828 targets MYB family genes involved in pigment biosynthesis.
• This regulation is linked to the red fruit trait in Ananas comosus var. bracteatus.

Conclusions:

• MIR828 plays a crucial role in pineapple fruit coloration.
• The presence of MIR828 in pineapple, previously thought absent in Poales, offers insights into monocot fruit evolution.
• MIR828's ancient origin (plesiomorphy) may explain convergent evolution of fleshy fruits in monocots.