MicroRNAs and targets in senescent litchi fruit during ambient storage and post-cold storage shelf life

Abstract

BackgroundLitchi has a high commercial value due to its bright color and rich nutrients. However, it deteriorates with the pericarp turning brown within 1–2 days after harvest. The factors that mediate litchi fruit senescence are complicated. MicroRNAs act as negative regulators involved in almost every physiological process. To understand the mechanism of litchi fruit senescence and pericarp browning at the miRNA level, five small RNA libraries and a degradome library prepared from the pericarp of litchi fruit subjected to ambient storage and post-cold storage shelf life were sequenced.ResultsBy aligning the sRNA reads onto the litchi unigene assembly, 296 miRNAs belonging to 49 known miRNA families were first identified from litchi. In addition, 11 litchi-specific miRNAs were identified. Among these, 167 known miRNAs were identified to cleave 197 targets, and three litchi-specific miRNAs were found to have five targets. Through combined analysis of stem-loop quantitative real-time polymerase chain reaction (qRT-PCR) and transcriptome profiling, 14 miRNA-target pairs were found to be actively involved in litchi fruit senescence-related processes, including energy regulation, anthocyanin metabolism, hormone signaling, and pathogen-infection defense.ConclusionsA network of miRNA-targets that regulate litchi fruit senescence has been proposed, revealing the miRNA-mediated regulation in senescent litchi fruit. This will aid in developing new strategies to postpone the senescence of litchi fruit and other horticultural products.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-015-0509-2) contains supplementary material, which is available to authorized users.

Identification of MicroRNAs and Their Target Genes Related to the Accumulation of Anthocyanins in Litchi chinensis by High-Throughput Sequencing and Degradome Analysis

“…In this study, we constructed four sRNA libraries and two mixed degradome libraries from pericarps of ‘FZX’ litchi of different developmental phases. In general, 24 nt sRNAs were the most abundant, followed by 21 nt, which was consistent with the length distribution of sRNAs reported in apple and litchi (Xia et al, 2012; Yao et al, 2015). Finally, a total of 78 known miRNAs belonging to 35 highly conserved miRNA families as well as 41 new miRNA were identified in litchi (Supplementary Tables S3 and S4).…”

“…Litchi miRNAs and targets had been identified in litchi fruit subjected to ambient storage and post-cold storage shelf life (Yao et al, 2015). However, whether miRNAs are involved in litchi anthocyanin biosynthesis is still unknown.…”

Integrated sRNAome and RNA-Seq Analysis Reveals miRNA Effects on Betalain Biosynthesis in Pitaya

“…The percentage of 24 nt sRNAs (an average of 58.03%) was much higher than that of 21 nt sRNAs (an average of 12.16%) in pitaya pulp ( Figure S1). The result was consistent with the length distribution of sRNAs in apple and litchi [15,20,58], but was inconsistent with the ndings in strawberry, orange, Brassica juncea, and apple [ [13,20,21,23]. Bgy-mir156 regulates the target gene phytoene synthase (PSY) and affects the accumulation of carotenoids in carrot (Daucus carota) [12].…”

Integrated sRNAome and RNA-Seq Analysis Reveals miRNA Effects on Betalain Biosynthesis in Pitaya

“…1). The result was consistent with the length distribution of sRNAs in apple and litchi [15,20,57] but was inconsistent with the findings in strawberry, orange, Brassica juncea, and apple [21,[58][59][60] Bgy-mir156 regulates the target gene phytoene synthase (PSY) and affects the accumulation of carotenoids in carrot (Daucus carota L.) [12]. Betalains are secondary metabolites but cannot co-exist naturally in one plant at the same time [61].…”