Identification of miRNAs and their targets in tea (Camellia sinensis)

Abstract

MicroRNAs (miRNAs) are endogenous small RNAs playing a crucial role in plant growth and development, as well as stress responses. Among them, some are highly evolutionally conserved in the plant kingdom, this provide a powerful strategy for identifying miRNAs in a new species. Tea (Camellia sinensis) is one of the most important commercial beverage crops in the world, but only a limited number of miRNAs have been identified. In the present study, a total of 14 new C. sinensis miRNAs were identified by expressed sequence tag (EST) analysis from 47 452 available C. sinensis ESTs. These miRNAs potentially target 51 mRNAs, which can act as transcription factors, and participate in stress response, transmembrane transport, and signal transduction. Analysis of gene ontology (GO), based on these targets, suggested that 37 biological processes were involved, such as oxidation-reduction process, stress response, and transport. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis inferred that the identified miRNAs took part in 13 metabolic networks. Our study will help further understanding of the essential roles of miRNAs in C. sinensis growth and development, and stress response.

MicroRNA Networks in Plant-Microorganism Interactions

“…Study carried out in avocado infected with Phytophthora cinnamomi, the most destructive root pathogen of avocado, revealed that cytochrome P450-like TBP (TATA box binding protein) was significantly induced at 3 and 12 h after infection (Mahomed and Berg 2011). Interestingly, cytochrome P450-like TBP was identified as target of miR2911 in Camelia sinensis (Zhu and Luo 2013). Up-regulation of miR2911 was observed in root tissues of orchid Oncidium colonized by the endophytic fungus Piriformospora indica (Ye et al 2014).…”

Molecular Markers

“…Among the other genomic resources, while Kamunya et al (2010) identified 23 minor QTLs, approximately 250 polymorphic SSR markers were validated by various groups (Kato et al 2008, Sharma et al 2009). Apart from that, a few SNPs ) and microRNAs of tea (Das and Mondal 2010;Prabu and Mandal 2010;Mohanpuria and Yadav 2012;Zhu and Luo 2013) had also been identified.…”

Selection and Verification of Candidate Reference Genes for Mature MicroRNA Expression by Quantitative RT-PCR in the Tea Plant (Camellia sinensis)

“…There is currently a focus on the microRNAs of tea plants. Some conserved miRNAs have been predicted based on sequence homology with full length nucleotide sequence databases [31,32,33] and six novel miRNAs have been identified by isolating and cloning of small RNA libraries [34]. Recently, Jeyaraj et al (2014) [35] analyzed expression and validation of several Camellia sinensis miRNAs in bud tissues by using the stem-loop pulse qRT-PCR method.…”