Lucas Mikaël, Godin C., Jay Allemand C., Laplaze Laurent. (2008). Auxin fluxes in the root apex co-regulate gravitropism and lateral root initiation. Journal of Experimental Botany, 59 (1), p. 55-66. ISSN 0022-0957.
Titre du document
Auxin fluxes in the root apex co-regulate gravitropism and lateral root initiation
Lucas Mikaël, Godin C., Jay Allemand C., Laplaze Laurent
Source
Journal of Experimental Botany, 2008,
59 (1), p. 55-66 ISSN 0022-0957
Root architecture plays an important role in water and nutrient acquisition and in the ability of the plant to adapt to the soil. Lateral root development is the main determinant of the shape of the root system and is controlled by external factors such as nutrient concentration. Here it is shown that lateral root initiation and root gravitropism, two processes that are regulated by auxin, are co-regulated in Arabidopsis. A mathematical model was generated that can predict the effects of gravistimulations on lateral root initiation density and suggests that lateral root initiation is controlled by an inhibitory fields mechanism. Moreover, gene transactivation experiments suggest a mechanism involving a single auxin transport route for both responses. Finally, co-regulation may offer a selective advantage by optimizing soil exploration as supported by a simple quantitative analysis.
