Description:
<jats:p>By use of differential display, we have isolated a new early auxin‐responsive cDNA in <jats:italic>Nicotiana tabacum</jats:italic>. <jats:italic>Nt‐gh3</jats:italic> had 70% identity with the unique <jats:italic>GH3</jats:italic> sequence isolated in soybean by Hagen et al. [Planta 162 (1984) 147–153] and is thus the first reported cDNA related to this gene until now. <jats:italic>Nt‐gh3</jats:italic> mRNA accumulates within a short time after auxin treatment, responds to very low concentrations of NAA (as little as 10<jats:sup>−9</jats:sup> M) and specifically to active auxins. <jats:italic>Nt‐gh3</jats:italic> mRNA is demonstrated to be one of the most relevant early molecular markers of primary auxin response.</jats:p>