The role of mir160 and arf10 in the auxin-mediated plant reproduction control

COLONO CAROLINA; COLOMBO LUCIA; AZZARO CELESTE ANTONELA; MENDES MARTA; PESSINO SILVINA CLAUIDIA; CONSTANTINI ELENA

Mendoza

Congreso; XVII Congreso Latinoamericano de Genética; 2019

Apomixis (asexual reproduction via seeds) is considered an evolutionary deviation from sexuality, caused by genetic/epigenetic variations involving one or several developmental genes. In previous comparative transcriptome analyses, we determined that the auxin-controlled genes miR160 and ARF10 (one of the miR160 targets) display up- and down- regulation, respectively, in apomictic plants. The objective of this work was to explore a hypothetical miRNA160/ARF10 reproductive function in the Arabidopsis thaliana sexual model. Analysis of pARF10:ARF10-GFP lines revealed ARF10 canonical expression in a single cell layer surrounding the megaspore mother cell (MMC). An arf10 defective line carrying a 5?UTR-located T insertion showed a 3-fold gene expression reduction, 5.96% (2.94 < P < 11.35) ovule abortion and MMC delayed entrance into meiosis. arf10 x pKNU:GFP crosses displayed a significant reduction in the number of MMCs. miRNA160-insensitive pARF10::ARF10-GFP lines showed ARF10 expression in the entire ovule.showing that miRNA160 regulates ARF10 expression in MMCs, nucella and integuments. Consequently, in wilt type plants, ARF10 expression gets confined to a single cell layer surrounding the MMC due to the activity of miRNA160.