Isolation of high-quality RNA from high-phenolic tissues of eelgrass (Zostera marina L.) by keeping temperature low

We describe a modified LiC1 method for isolating good-quality RNA from leaves, rhizomes and roots of eelgrass (Zostera marina L.) which are rich in phenolic compounds. In ordinary protocols, RNA extraction was strongly inhibited by contamination with the large amounts of polyphenol compounds. Only by keeping the temperature low during extraction could RNA be successfully isolated. The resulting high-quality RNA was suitable for reverse transcription-polymerase chain reaction, reverse transcription followed by quantitative real-time PCR, cDNA library construction and Northern blot analysis. The total RNA extracted from leaves was much higher than that from rhizomes and roots. Using this method, 20–40 μg of total RNA was routinely obtained from 1 g of fresh tissue. This is the first report of low temperature RNA extraction from plant tissues rich in phenolic compounds.