normalizing northerns of plants

[Andreas Vogel]

Hi everyone,

I am going to study gene expression of an enzyme from red kidney bean 
(Phaseolus vulgaris) by Northern Blots. By checking the literature I couldnt 
find any Blot which was normalized to an internal standard (ribosomal RNA, 
GAPDH,...). Since I am not a botanist I dont know whether it is difficult to 
find 
a constitutive expressed gene in plants or all the researchers normalize on 
total RNA amount because there is few sequence information available? 
In our group we cloned alpha tubulin from Phaseolus vulgaris. Does anyone know 
if it is suitable to normalize Northerns? 

Thanks in advance,
Andreas