Isolation of High-Quality RNA from Reaumuria soongorica, a Desert Plant Rich in Secondary Metabolites

RNA isolation is a prerequisite for the study of the molecular mechanisms of stress tolerance in the desert plant Reaumuria soongorica, an extreme xeric semi-shrub. However, R. soongorica that contains high levels of secondary metabolites that co-precipitate with RNA, making RNA isolation difficult. Here the authors propose a new protocol suitable for isolating high-quality RNA from the leaves of R. soongorica. Based on a CTAB method described by Liu et al., the protocol has been improved as follows: the samples were ground with PVPP to effectively inhibit the oxidation of phenolics, contaminating DNA was removed with DNase I, and NaAc was used along with ethanol for precipitation to enhance the RNA yield and shorten the precipitation time. Gel electrophoresis and spectrophotometric analysis indicated that this isolation method provides RNA with no DNA contamination. Moreover, the yield (183.79 +/- A 40.36 mu g/g) and quality were superior to those using the method of Liu et al., which yields RNA with significant DNA contamination at 126.30 +/- A 29.43 mu g/g. Gene amplification showed that the RNA obtained using this protocol is suitable for use in downstream molecular procedures. This method was found to work equally well for isolating RNA from other desert plants. Thus, it is likely to be widely applicable.