ИСТИНА

Mechanisms of the root hairs tip growth are typically studied in the completely illuminated plants. We have suggested that mechanisms of the root growth and development in the dark may differ from those established for the light-grown plants. We have observed unusual root development of the Arabidopsis grown for 5-6 days in the dark. The most striking difference was observed in the root hairs length: in the root apex it was lower than the root hairs length in the root apex of Arabidopsis seedlings grown in sterile conditions under 16/8 h photoperiod and 20ºC. Contrary, the root hairs length in the upper part of the root was higher than in light-grown plants. We propose that this difference may be related to the different reactive oxygen species (ROS) production in these zones. Previously, we have observed the absence of the ROS production in the root apex of the dark-grown Arabidopsis seedlings, but slight ROS-dependent nitroblue tetrazolium staining in the root upper region with the high density of the root hairs. We have found that ROS production could be induced by light. The question is to be solved whether the root hairs tip growth could be affected by light or different hormonal balance in the dark grown Arabidopsis influence the length of the root hairs.