MicroRNAs play an important role in the regulation of strawberry fruit senescence in low temperature

Abstract To understand the microRNAs (miRNAs)-mediated mechanism of low temperature delaying non-climacteric strawberry fruit senescence during postharvest period, two small RNA (sRNA) libraries from strawberry fruit stored at low temperature for 24 and 48 h were constructed. A total of 88 known and 1224 novel potential candidate miRNAs were obtained and analyzed. Compared with the expression of miRNAs in strawberry fruit stored for 0 h, 108 miRNAs were up-regulated and 113 were down-regulated in fruit stored at 24 h, and 139 miRNAs were up-regulated and 114 were down-regulated in fruit stored at 48 h. In the process of fruit storage under low temperature, PC-5p-176409_20 repressed abscisic acid (ABA) signaling transduction via the PYR1/PYL1-PP2C-SnRK2 network, miR167 reduced the jasmonic acid (JA) biosynthesis by targeting auxin response factor 8 ( ARF8 ), and by which they were involved in delaying fruit senescence. MiR164, miR172, PC-5p-67794_53 and PC-5p-1004_3092 up- or down-regulated the expression of their target genes, NAC transcription factors , APETALA2.7 (AP2.7) transcription factor , alpha/beta-hydrolases superfamily protein and glycosyl hydrolase 9B1 , respectively, and also involved in delaying fruit senescence under low temperature. These results give valuable information for understanding the role of miRNA in mediating the fruit senescence at low temperature.