The Gravi-2 experiment was launched on flight SpaceX3 in April 2014 (http://lensesinspace.wordpress.com/) and was performed on-board the ISS in May 2014 with EMCS (European Modular Cultivation System). ; Gravity is considered to be an important environmental factor in the orientation of plant growth. In the case of roots, signal gravity is perceived by specialized cells located in the root apex and, so called statocytes. Even if it is well known that the movements of amyloplasts (located in the statocytes) induce a series of signalling pathways, the role of amyloplasts displacement is not clearly elucidated. The objective of the GRAVI-2 project is to study the impact of amyloplasts displacement on the calcium-dependant pathways and thus, better understanding the gravity perception in lentil roots. The Gravi-2 experiment was launched on flight SpaceX3 in April 2014 (http://lensesinspace.wordpress.com/) and was performed on-board the ISS in May 2014 with EMCS (European Modular Cultivation System). Lentil seeds were germinated on the International Space Station (ISS) in different situations: (1) continuously in microgravity conditions (e.g. 10-4 g), (2) 10-2 g during 8 hours after a growth period of 23 hours in microgravity, (3) 2g during 5 minutes after a growth period of around 31 hours in microgravity, and (4) 2g during 15 minutes after a growth period of around 31 hours in microgravity. The studies will be performed using complementary approaches including the analysis of amyloplast positioning, calcium localisation and the level of expression of genes.