Abstract
Abscisic acid (ABA) is a critical plant hormone for fruit ripening and adaptive stress responses in strawberry. Previous high-throughput sequencing results indicated that ABA-insensitive (ABI)5, an important transcription factor in the ABA signaling pathway, was a target for a novel microRNA (miRNA), Fan-miR73. In the present study, exogenous ABA treatment was found to accelerate fruit ripening through differentially regulating the transcripts of ABA metabolism and signal transduction related genes, including NCED1, PYR1, ABI1, and SnRK2.2. Expression of Fan-miR73 was down-regulated in response to exogenous ABA treatment in a dosage-dependent manner, which resulted in an accumulation of ABI5 transcripts in the ripening-accelerated fruits. In addition, both UV-B radiation and salinity stress reduced the transcript levels of Fan-miR73, whereas promoted ABI5 expression. Furthermore, high negative correlations between the transcriptional abundance of Fan-miR73 and ABI5 were observed during ripening and in response to stress stimuli. These results enriched the possible regulatory role of miRNA involved in the post-transcriptional modification of ABI5 during strawberry ripening, as well as responses to environmental stresses.
Highlights
Abscisic acid (ABA) plays important roles in a vast array of plant developmental processes, such as seedling germination, fruit development and ripening, and responses to stress stimuli[1]
More than 500 novel miRNAs in Fragaria ananassa were identified in our previous high-throughput sequencing results, among which Fan-miR73 was of special interest because its target mRNA, ABI5, encodes an important transcription factor in the ABA signaling pathway
The secondary structure of the pre-miRNA of Fan-miR73 is shown in Fig. 1A, and the colored sequence indicates the mature miRNA whose cluster appeared at the 5′end
Summary
Abscisic acid (ABA) plays important roles in a vast array of plant developmental processes, such as seedling germination, fruit development and ripening, and responses to stress stimuli[1]. With respect to ABA signaling, an ABA receptor PYR1 was proven to play a positive role in strawberry fruit ripening through regulation of a variety of ABA-responsive genes, including ABI1 and SnRK213. Despite the well-elucidated functions of ABA signaling pathway in strawberry fruit ripening, the specific regulatory mechanisms driving expressions of these components remains elusive. It has been proven that miRNAs could target ABA signaling related components to regulate their expression in adaptive stress responses. In addition to stress response, an increasing number of studies have recently revealed that miRNAs acted as important mediator in plant development through the post-transcriptional regulation on phytohormone metabolism and/or signaling. The interrelation between Fan-miR73 and ABI5 was further investigated in response to salt stress and UV-B radiation
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call