Soybeans hypocotyl with auxin, treatment

Figure 3. 2-D Gel Electrophoresis of in vitro Translated Soybean Hypocotyl mRNA. Numbers to the left indicate migration of molecular weight markers (kilodaltons). The separating gel was 12% polyacrylamide. Numbered arrows indicate polypeptides that are up-regulated by BR while lettered arrows show polypeptides that are down-regulated in response to BR. Other experimental details are described in the text. A = hypocotyl sections auxin-depleted for 2 hours followed by buffer treatment for 2 hours A = as in A with 340 nM BR replacing buffer treatment.

In most cases, a detectable induction of mRNA levels is observed within 15-30 min following auxin exposure. The levels of three soybean mRNAs (detected by the cDNA clones 6, lOA and 15) are induced by 2.5 min of treatment of excised elongating soybean hypocotyl sections with the synthetic auxin 2,4-D [8]. These mRNAs and others identified in soybean [5, 16], pea [13] and tobacco [14] are specifically induced by auxins such as lAA and NAA, and not induced by nonauxin analogs. With some exceptions, these auxin-induced sequences do not accumulate in response to other plant growth regulators such as GA, ABA, cytokinins and ethylene, or to environmental stresses such as heat shock or cold... 

---