Question

Auxins are antagonist to ethylene how and why ??


please tell the correct answer and I will mark you as brainliest !!​

Answer 1

We investigated the growth and development of flax roots in the presence of auxin antagonists 4,4,4-trifluoro-3-(indole-3-)-butyric acid (TFIBA), p-chlorophenoxyisobutyric acid (PCIB), and the ethylene inhibitor silver thiosulfate. Of these compounds, silver thiosulfate was most effective in promoting root elongation. All compounds reduced root diameter and root hair development. The effects of TFIBA were reversed by exogenous indole-3-acetic acid (IAA) or 1-aminocyclopropane-1-carboxylic acid (ACC). Because the ethylene and ACC content of roots was reduced by TFIBA and PCIB but increased by silver thiosulfate, we measured the transcription level of five isoforms of ACC synthases (Lu-ACS1-5) and three isoforms of ACC oxidases (Lu-ACO1-3). Lu-ACS1-3 were inhibited by TFIBA and PCIB but promoted by silver thiosulfate and by exogenous IAA. TFIBA inhibited all three ACC oxidase isoforms but PCIB inhibited only Lu-ACO3. Silver thiosulfate and IAA upregulated Lu-ACO1 and Lu-ACO2. Exogenous IAA affected transcription of ACC synthases and ACC oxidases in a concentration-dependent manner. The root promotion by TFIBA and PCIB is related to ethylene, but may also involve auxin interactions.