Figure 2.

Effect of Suc and nitrogen on the expression of the Arabidopsis AK/HSD gene. Arabidopsis seedlings were incubated in the absence (C) or in the presence of Suc (S), mannitol (M), Asn (A), Gln (G), or NH₄NO₃ (N) as described in Methods. a, AK/HSD mRNA level was assayed in northern blots and hybridized with an AK/HSD cDNA probe (top). The intensity of the 28S rRNA bands upon methylene blue staining of the same blot prior to hybridization is given at the bottom. b, The average quantitative hybridization signals from blots of three separate experiments similar to the one shown in a were obtained by phosphor-imager scanning using the MacBAS program. Bars on top of the histograms represent the ses.