miRNA Profiling and Its Role in Multi-Omics Regulatory Networks Connected with Somaclonal Variation in Cucumber (Cucumis sativus L.) (original) (raw)

In silico analysis of putative miRNAs and their target genes in sorghum (Sorghum bicolor)

International Journal of Bioinformatics Research and Applications, 2013

MicroRNAs (miRNAs) are small endogenous genes regulators which regulate different processes underlying plant adaptation to abiotic stresses. To gain a deep understanding of role of miRNAs in plants, in the present study, we computationally analyzed different sorghum miRNAs in the drought-induced gene sequences. Homologous miRNA were identified using different plant miRNA databases. Using previously established genes databases, various targets of sorghum miRNAs were predicted viz: transcription factors, chaperonins, metabolic enzymes and other gene targets necessary for proper plant development. Analysis of cis-elements provides molecular evidence for the possible involvement of miRNAs in the process of abiotic stress tolerance in sorghum. Based on these results, it was suggested that miRNAs may play an important role in water stress tolerance.

High-throughput sequencing, characterization and detection of new and conserved cucumber miRNAs

PloS one, 2011

Micro RNAS (miRNAs) are a class of endogenous small non coding RNAs involved in the post-transcriptional regulation of gene expression. In plants, a great number of conserved and specific miRNAs, mainly arising from model species, have been identified to date. However less is known about the diversity of these regulatory RNAs in vegetal species with agricultural and/or horticultural importance. Here we report a combined approach of bioinformatics prediction, high-throughput sequencing data and molecular methods to analyze miRNAs populations in cucumber (Cucumis sativus) plants. A set of 19 conserved and 6 known but non-conserved miRNA families were found in our cucumber small RNA dataset. We also identified 7 (3 with their miRNA* strand) not previously described miRNAs, candidates to be cucumber-specific. To validate their description these new C. sativus miRNAs were detected by northern blot hybridization. Additionally, potential targets for most conserved and new miRNAs were identified in cucumber genome. In summary, in this study we have identified, by first time, conserved, known non-conserved and new miRNAs arising from an agronomically important species such as C. sativus. The detection of this complex population of regulatory small RNAs suggests that similarly to that observe in other plant species, cucumber miRNAs may possibly play an important role in diverse biological and metabolic processes. Citation: Martínez G, Forment J, Llave C, Pallás V, Gó mez G (2011) High-Throughput Sequencing, Characterization and Detection of New and Conserved Cucumber miRNAs. PLoS ONE 6(5): e19523.

Genome-wide identification of microRNAs in pomegranate (Punica granatum L.) by high-throughput sequencing

Background: MicroRNAs (miRNAs), a class of small non-coding endogenous RNAs that regulate gene expression post-transcriptionally, play multiple key roles in plant growth and development and in biotic and abiotic stress response. Knowledge and roles of miRNAs in pomegranate fruit development have not been explored. Results: Pomegranate, which accumulates a large amount of anthocyanins in skin and arils, is valuable to human health, mainly because of its antioxidant properties. In this study, we developed a small RNA library from pooled RNA samples from young seedlings to mature fruits and identified both conserved and pomegranate-specific miRNA from 29,948,480 high-quality reads. For the pool of 15-to 30-nt small RNAs, ~50 % were 24 nt. The miR157 family was the most abundant, followed by miR156, miR166, and miR168, with variants within each family. The base bias at the first position from the 5' end had a strong preference for U for most 18-to 26-nt sRNAs but a preference for A for 18-nt sRNAs. In addition, for all 24-nt sRNAs, the nucleotide U was preferred (97 %) in the first position. Stem-loop RT-qPCR was used to validate the expression of the predominant miRNAs and novel miRNAs in leaves, male and female flowers, and multiple fruit developmental stages; miR156, miR156a, miR159a, miR159b, and miR319b were upregulated during the later stages of fruit development. Higher expression of miR156 in later fruit developmental may positively regulate anthocyanin biosynthesis by reducing SPL transcription factor. Novel miRNAs showed variation in expression among different tissues. These novel miRNAs targeted different transcription factors and hormone related regulators. Gene ontology and KEGG pathway analyses revealed predominant metabolic processes and catalytic activities, important for fruit development. In addition, KEGG pathway analyses revealed the involvement of miRNAs in ascorbate and linolenic acid, starch and sucrose metabolism; RNA transport; plant hormone signaling pathways; and circadian clock.

Identification and temporal expression analysis of conserved and novel microRNAs in Sorghum

Genomics, 2011

Sweet Sorghum is largely grown for grain production but also recently emerged as one of the model feedstock plants for biofuel production. In plants, microRNA (miRNA)-guided gene regulation plays a key role in diverse biological processes, thus, their identification in different plant species is essential to understand post-transcriptional gene regulation. To identify miRNAs in Sorghum, we sequenced a small RNA library. Sequence analysis revealed the identity of 29 conserved miRNA families. Importantly, 13 novel miRNAs are identified, seven of which are conserved in closely related monocots. Temporal expression analysis of conserved and novel miRNAs indicated differential expression of several miRNAs. Approximately 125 genes that play diverse roles have been predicted as targets and a few targets were experimentally validated. These results provided insights into miRNA-controlled processes in Sorghum and also laid the foundation for manipulating miRNAs or their targets for improving biomass production and stress tolerance in Sorghum.

Dynamic Regulation of Novel and Conserved miRNAs Across Various Tissues of Diverse Cucurbit Species

Plant Molecular Biology Reporter, 2013

MicroRNA genes (miRNAs) encoding small noncoding RNAs are abundant in plant genomes and play a key role in regulating several biological mechanisms. Five conserved miRNAs, miR156, miR168-1, miR168-2, miR164, and miR166 were selected for analysis from the 21 known plant miRNA families that were recovered from deep sequencing data of small RNA libraries of pumpkin and squash. A total of six novel miRNAs that were not reported before were found to have precursors with reliable fold-back structures and hence considered novel and were designated as cuc_nov_miRNAs. A set of five conserved, six novel miRNAs, and five uncharacterized small RNAs from the deep sequencing data were profiled for their dynamic regulation using qPCR. The miRNAs were evaluated for differential regulation across the tissues among four diverse cucurbit species, including pumpkin and squash (Cucurbita moschata Duch. Ex Poir. and Cucurbita pepo L.), bitter melon (Momordica charantia L.), and Luffa (Loofah) (Luffa acutangula Roxb.). Expression analysis revealed differential regulation of various miRNAs in leaf, stem, and fruit tissues. Importantly, differences in the expression levels were also found in the leaves and fruits of closely related C. moschata and C. pepo. Comparative miRNA profiling and expression analysis in four cucurbits led to identification of conserved miRNAs in cucurbits. Predicted targets for two of the conserved miRNAs suggested miRNAs are involved in regulating similar biological mechanisms in various species of cucurbits.

Effect of Transgenesis on mRNA and miRNA Profiles in Cucumber Fruits Expressing Thaumatin II

Genes, 2020

Transgenic plants are commonly used in breeding programs because of the various features that can be introduced. However, unintended effects caused by genetic transformation are still a topic of concern. This makes research on the nutritional safety of transgenic crop plants extremely interesting. Cucumber (Cucumis sativus L.) is a crop that is grown worldwide. The aim of this study was to identify and characterize differentially expressed genes and regulatory miRNAs in transgenic cucumber fruits that contain the thaumatin II gene, which encodes the sweet-tasting protein thaumatin II, by NGS sequencing. We compared the fruit transcriptomes and miRNomes of three transgenic cucumber lines with wild-type cucumber. In total, we found 47 differentially expressed genes between control and all three transgenic lines. We performed the bioinformatic functional analysis and gene ontology classification. We also identified 12 differentially regulated miRNAs, from which three can influence the two targets (assigned as DEGs) in one of the studied transgenic lines (line 224). We found that the transformation of cucumber with thaumatin II and expression of the transgene had minimal impact on gene expression and epigenetic regulation by miRNA, in the cucumber fruits.

MicroRNAs and their targets in cucumber shoot apices in response to temperature and photoperiod

BMC Genomics

Background: The cucumber is one of the most important vegetables worldwide and is used as a research model for study of phloem transport, sex determination and temperature-photoperiod physiology. The shoot apex is the most important plant tissue in which the cell fate and organ meristems have been determined. In this study, a series of whole-genome small RNA, degradome and transcriptome analyses were performed on cucumber shoot apical tissues treated with high vs. low temperature and long vs. short photoperiod. Results: A total of 164 known miRNAs derived from 68 families and 203 novel miRNAs from 182 families were identified. Their 4611 targets were predicted using psRobot and TargetFinder, amongst which 349 were validated by degradome sequencing. Fourteen targets of six miRNAs were differentially expressed between the treatments. A total of eight known and 16 novel miRNAs were affected by temperature and photoperiod. Functional annotations revealed that "Plant hormone signal transduction" pathway was significantly over-represented in the miRNA targets. The miR156/157/SBP-Boxes and novel-mir153/ethylene-responsive transcription factor/senescence-related protein/ aminotransferase/acyl-CoA thioesterase are the two most credible miRNA/targets combinations modulating the plant's responsive processes to the temperature-photoperiod changes. Moreover, the newly evolved, cucumberspecific novel miRNA (novel-mir153) was found to target 2087 mRNAs by prediction and has 232 targets proven by degradome analysis, accounting for 45.26-58.88% of the total miRNA targets in this plant. This is the largest sum of genes targeted by a single miRNA to the best of our knowledge. Conclusions: These results contribute to a better understanding of the miRNAs mediating plant adaptation to combinations of temperature and photoperiod and sheds light on the recent evolution of new miRNAs in cucumber.

In silico identification and functional annotation of miRNAs and their targets from EST and GSS of onion (Allium cepa L.)

MicroRNAs are a class of approximately 20-24 nucleotides (nt) endogenous small RNAs that negatively regulate gene expression and play vital roles in multiple biological processes, including plant growth, development and responses to environmental stresses. Onion (Allium cepa L.), also called as "queen of kitchen" is a bulbous vegetable crop cultivated in almost all parts of the world. However, the miRNA repertoire of onion is highly ambiguous. In the present study, we report the computational identification of miRNAs and their targets from expressed sequence tags (ESTs) and genome survey sequences (GSSs) of Allium cepa L as well as functionally annotated the target genes. By following a stringent pipeline, we used 20225 ESTs and 10725 GSS from onion to identify 9 new potential miRNA belonging to 8 different miRNA families (miR172, miR1134, miR1223, miR6219, miR7725, miR8570, miR8703 and miR8752). Under a stringent condition, 26 potential targets were identified for the 8 miRNAs with distinct functions related to growth and development, signal transduction, metabolism, defense and stress responses. Overall, the present finding will make the pathway for understanding of molecular mechanisms of miRNA in onion and understanding their involvement in post-transcriptional gene silencing mechanism towards regulation of stress responses in this economically important plant.

High-resolution experimental and computational profiling of tissue-specific known and novel miRNAs in Arabidopsis

Genome Research, 2012

Small non-coding RNAs (ncRNAs) are key regulators of plant development through modulation of the processing, stability, and translation of larger RNAs. We present small RNA data sets comprising more than 200 million aligned Illumina sequence reads covering all major cell types of the root as well as four distinct developmental zones. MicroRNAs (miRNAs) constitute a class of small ncRNAs that are particularly important for development. Of the 243 known miRNAs, 133 were found to be expressed in the root, and most showed tissue-or zone-specific expression patterns. We identified 66 new high-confidence miRNAs using a computational pipeline, PIPmiR, specifically developed for the identification of plant miRNAs. PIPmiR uses a probabilistic model that combines RNA structure and expression information to identify miRNAs with high precision. Knockdown of three of the newly identified miRNAs results in altered root growth phenotypes, confirming that novel miRNAs predicted by PIPmiR have functional relevance.