Help with RNA extraction from tobacco stem

[Ken McNeil]

Dear Netters
While I am able to extract good quantities of clean total RNA from 1 g of greenhouse-grown tobacco leaves using Ausubel et al.'s phenol/SDS extraction and LiCl precipitation protocol, I obtain no detectable RNA from up to 10 g of chronologically young tobacco stems using the same protocol.  Tissues are frozen in liquid nitrogen immediately after excision.  Tissues are then ground to a powder with a mortar and pestle and homogenized for about 2 min. - I don't think a lack of thorough grinding is the problem


.  Does anyone have any suggestions on how to deal with this problem?  Have people found that, in general, stems and petioles contain much lower levels of RNA than leaves?
Thanks for your help.    Ken