U should re-precipitate the RNA after isolation using equal volume isopropanol or Na acetate+ absolute ethanol. Such re-precipitation helps in removing the excess phenolics and other organic impurities. Just simply carry put another round of precipitation. It has always helped me in improving the 260/230ratio from as low as 1.6 to 2.1

I had the same problem with my tree roots. You can increase PVP up to 10% and increase the volume of extraction buffer for the same weight of material. Currently I test Agilent and Isogen RNA extraction kit for plant material rich in phenolic compounds.

Have a look at this method it worked well for me with mature apple fruit tissue.

Plant Molecular Biology Reporter

December 2004, Volume 22, Issue 4, pp 437-438

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

Ksenija Gasic,

Alvaro Hernandez,

Schuyler S. Korban

U should re-precipitate the RNA after isolation using equal volume isopropanol or Na acetate+ absolute ethanol. Such re-precipitation helps in removing the excess phenolics and other organic impurities. Just simply carry put another round of precipitation. It has always helped me in improving the 260/230ratio from as low as 1.6 to 2.1

 @Vijay Suresh Akhade ;

Regarding your answer here, what concentrations are recommended to be used of Na acetate+ absolute ethanol to improve the isolation of RNA from a desert plant.

Thank you in advance.

0.1 volumes of 5M sodium acetate (pH = 5.2) and 2 volumes of ice cold absolute EtOH works well