RNA extraction from different apple tissues rich in polyphenols and polysaccharides for cDNA library construction

Abstract

Recovering RNA of high quality and quantity is a prerequisite for ensuring representation of all expressed genes in a cDNA library. An efficient procedure for isolating RNA from bud, internodal shoot, flower, and fruit tissues of apple has been developed. This protocol does not involve the use of phenol, lyophilization, or ultracentrifugation. In addition, this protocol overcomes problems of both RNA degradation and low yield attributed to oxidation by polyphenolic compounds and coprecipitation with polysaccharides, both abundant components in apple fruit and flower tissues. Isolated RNA is of high quality and is undegraded as assessed by spectrophotometric readings and electrophoresis in denaturing agarose gels. RNA quality is further assessed following its use in reverse transcription and cDNA library construction, and it can be used for a number of downstream analyses, including Northern blot hybridization and reverse transcription-polymerase chain reaction (RT-PCR). With this modified protocol, 25–900 μg of total RNA is routinely obtained from 1 g of fresh material. This method is of low cost and easy to perform.