Fig. 4. Northern analysis of four cDNA clones isolated by genomic and cDNA library screening. Total RNA was isolated from young roots (R), stems (S), and leaves (L). The 18S rRNA signal was used for standardizing the signal level per lane. Autoradiographs were exposed for 1 d for STUB, half day for SPRP1 and 3 d for SAQ1 and SEF1.