ROLE OF IAA IN THE ROOT MASS ACCUMULATION OF ARABIDOPSIS DEPENDING ON PLANT SENSITIVITY TO ETHYLENE
The work is devoted to the study of interaction of ethylene and auxin in regulation of the root mass accumulation. For this, the Arabidopsis plants of the parent ecotype Columbia, their ethylene-insensitive etr1-1 mutants, and transgenic plants transformed with auxin-sensitive DR5::GUS system were used. The root mass accumulation decreased in Columbia plants after treatments with IAA and an inhibitor of ethylene perception 1-methylcyclopropene (1-MCP). Roots of ethylene-insensitive mutants had a smaller mass, but at the same time they were characterized by a higher content of IAA compared with Columbia. It was concluded that ethylene plays an important role in maintaining of root mass accumulation by preventing excessive accumulation of IAA in roots. Treatment of transgenic DR5::GUS plants with 1-MCP resulted in an increase in the activity of glucoronidase, which indicates the up-regulation of auxin content by inhibitor of ethylene perception and confirms the inhibitory effect of ethylene on auxin accumulation.