Isolation of RNA from blackcurrant (Ribes nigrum L.) fruit

High quality RNA extraction from Maqui berry for its application in next-generation sequencing

Maqui berry (Aristotelia chilensis) is a native Chilean species that produces berries that are exceptionally rich in anthocyanins and natural antioxidants. These natural compounds provide an array of health benefits for humans, making them very desirable in a fruit. At the same time, these substances also interfere with nucleic acid preparations, making RNA extraction from Maqui berry a major challenge. Our group established a method for RNA extraction of Maqui berry with a high quality RNA (good purity, good integrity and higher yield). This procedure is based on the adapted CTAB method using high concentrations of PVP (4 %) and β-mercaptoethanol (4 %) and spermidine in the extraction buffer. These reagents help to remove contaminants such as polysaccharides, proteins, phenols and also prevent the oxidation of phenolic compounds. The high quality of RNA isolated through this method allowed its uses with success in molecular applications for this endemic Chilean fruit, such as differential expression analysis of RNA-Seq data using next generation sequencing (NGS). Furthermore, we consider that our method could potentially be used for other plant species with extremely high levels of antioxidants and anthocyanins.

High quality RNA isolation from ployphenol-, polysaccharide- and protein-rich tissues of lentil (Lens culinaris)

Current RNA isolation methods have limitations in their ability to yield good quality and quantity of RNA from plants that have high content of phenols, polysaccharides and storage proteins. Existing methods also do not eliminate accompanying chromosomal DNA in RNA preparation that causes false positives in gene expression studies. Standard isolation technique was modified for rapid and quick extraction of RNA, and lentil tissue most appropriate to extract good quality RNA was determined. The concentration of the phenol blocker polyvinylpyrrolidone in the extraction buffer was determined, DNase I was added to eliminate chromosomal DNA and the timing of this step was optimized. RNA up to 568 μg of RNA from 1 g of tissue was isolated from four different tissues of lentil in less than half the time typically required by reported methods. The method avoids the use of toxic phenol–chloroform, hazardous guanidinium thiocyanate (GTC) and laborious CsCl ultracentrifugation. Absorbance A260/A280 ratio of 1.9 and A260/A230 ratio of 2.7 reveal RNA to be of high purity. Modified method yielded RNA that was free from contaminants and suitable for RT-PCR and cDNA library construction.

Optimization of RNA isolation from Brittle Leaf Disease affected date palm leaves and construction of a subtractive cDNA library

A simple and efficient method was described here for the isolation of high-quality RNA from date palm leaves affected with Brittle Leaf Disease (BLD) and containing high amount of phenolic compounds. The procedure was based on the use of a non-ionic detergent Nonidet-P40 (NP-40), Polyvinylpyrrolidone (PVP), and beta-mercaptoethanol in the extraction buffer in order to isolate cytoplasmic RNA and to prevent the oxidation of phenolic compounds. This method allowed the isolation of intact RNA, suitable for cDNA synthesis and library construction. Differential screening of the subtractive cDNA library from affected leaf RNA led to the identification of some BLD-induced genes.

Extraction of total RNA from Chrysanthemum containing high levels of phenolic and carbohydrates

Some standard methods are available in total RNA extraction of plant tissue, which are effective for the ordinary plants. But it is difficult to extract the total RNA from the plants with high levels of phenolic compounds, carbohydrates, or other compounds that bind and/or coprecipitate with RNA. In this paper, a method was described that used the soluble polyvinylpyrrolidone (PVP), ethanol precipitation, phenol extraction and LiCl precipitation. By this method, RNA capable of reverse-transcription and polymerase chain reaction (PCR) amplification was isolated from Chrysanthemum that contains high levels of phenolic compounds and carbohydrates. The OD260/OD280 absorbance ratio is 2, and the RNA is intact. Other specialized RNA extraction methods failed to deliver suitable product. Bands of PCR products are clearly appearing on the polypropylene acyl gel electrophoresis (PAGE) gel, which indicates that the purity, concentration and integrity of total RNA were suitable for the sequent researches.

The construction of a genetic linkage map of red raspberry (Rubus idaeus subsp. idaeus) based on AFLPs, genomic-SSR and EST-SSR markers

Breeding in raspberry is time-consuming due to the highly heterozygous nature of this perennial fruit crop, coupled with relatively long periods of juvenility. The speed and precision of raspberry breeding can be improved by genetic linkage maps, thus facilitating the development of diagnostic markers for polygenic traits and the identification of genes controlling complex phenotypes. A genetic linkage map (789 cM) of the red raspberry Rubus idaeus has been constructed from a cross between two phenotypically different cultivars; the recent European cultivar Glen Moy and the older North American cultivar Latham. SSR markers were developed from both genomic and cDNA libraries from Glen Moy. These SSRs, together with AFLP markers, were utilised to create a linkage map. In order to test the utility of the genetic linkage map for QTL analysis, morphological data based on easily scoreable phenotypic traits were collected. The segregation of cane spininess, and the root sucker traits of density and spread from the mother plant, was quantified in two different environments. These traits were analysed for significant linkages to mapped markers using MapQTL and were found to be located on linkage group 2 for spines and group 8 for density and diameter. The availability of co-dominant markers allowed heterozygosities to be calculated for both cultivars.

The isolation of RNA from raspberry (Rubus idaeus) fruit

Previous attempts to extract high-quality, total RNA from raspberry (Rubus idaeus) fruits using published protocols have proven to be unsuccessful. Even the use of protocols developed for the extraction of RNA from other fruit tissue has resulted in low yields (1) or the isolation of degraded RNA (2). Here, we report on the development of a quick and simple method of extracting total RNA from raspberry fruit. Using this method, high yields of good quality, undegraded RNA were obtained from fruit at all stages of ripening. The RNA is of sufficient quality for northern analysis and cDNA library construction.