Morphoanatomy in the root of Arabidopsis thaliana submitted to cumarine (1,2-benzopyran)

Abstract

Morphoanatomy in the root of Arabidopsis thaliana submitted to cumarine (1,2-benzopyran) Coumarins can alter the germination and development of recipient species, in natural or controlled environments. The objective was to identify the effect of coumarin on Total Germination (GT (%), Average Germination Speed ​​(S), Accumulated Germination Speed ​​(AS) and Total Root Length (CTR), as well as the cumulative effect of coumarin on the morphology of the Arabidopsis thaliana root over time (7 and 14 days) The seeds were grown in square Petri dishes, containing agar and concentrations of coumarin composing the dose-response curve (0; 1.5; 3.0; 6.0; 12 and 24 µM). Coumarin was previously diluted in ethanol. As a control, ethanol added to agar. After determining the IC50 (14 µM), A. thaliana seeds were grown for 7 and 14 days. Cuts (0.7 μm) of the root tips were performed and stained with toluidine blue. Germination inhibition was dose-dependent, that is, the higher the coumarin concentration, the greater the germination inhibition 40%, AS and S was only 37% and the total length of the seedlings them decreased by 66%. The IC₅₀ induced thickening of the root apex, mainly at 14 days of cultivation, increased root hair, appearance of ectopic roots and asymmetric nuclei in the cells.