Citrus psorosis virus 24K protein interacts with citrus miRNA precursors, affects their processing and subsequent miRNA accumulation and target expression

CARINA A. REYES, ELIANA E. OCOLOTOBICHE, FACUNDO E. MARMISOLLÉ, GABRIEL ROBLES LUNA, MARÍA B. BORNIEGO, ARIEL A. BAZZINI, SEBASTIAN ASURMENDI AND M. LAURA GARCÍA; ARIEL A. BAZZINI,; SEBASTIAN ASURMENDI ; MARIA LAURA GARCIA

MOLECULAR PLANT PATHOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2015

1464-6722

Sweet orange (Citrus sinensis), one of the most important fruitcrops worldwide, may suffer from disease symptoms induced byvirus infections, thus resulting in dramatic economic losses. Here,we show that the infection of sweet orange plants with twoisolates of Citrus psorosis virus (CPsV) expressing different symptomatologyalters the accumulation of a set of endogenousmicroRNAs (miRNAs). Within these miRNAs, miR156, miR167 andmiR171 were the most down-regulated, with almost a three-foldreduction in infected samples. This down-regulation led to a concomitantup-regulation of some of their targets, such as Squamosapromoter-binding protein-like 9 and 13, as well as Scarecrow-like6. The processing of miRNA precursors, pre-miR156 and premiR171,in sweet orange seems to be affected by the virus. Forinstance, virus infection increases the level of unprocessed precursors,which is accompanied by a concomitant decrease in maturespecies accumulation. miR156a primary transcript accumulationremained unaltered, thus strongly suggesting a processingderegulation for this transcript. The co-immunoprecipitation ofviral 24K protein with pre-miR156a or pre-miR171a suggests thatthe alteration in the processing of these precursors might becaused by a direct or indirect interaction with this particular viralprotein. This result is also consistent with the nuclear localizationof both miRNA precursors and the CPsV 24K protein. This studycontributes to the understanding of the manner in which a viruscan alter host regulatory mechanisms, particularly miRNAbiogenesis and target expression.