Root gravity response module guides differential growth determining both root bending and apical hook formation in Arabidopsis

0509263 - ÚEB 2020 RIV GB eng J - Journal Article
Zhu, Q. - Gallemí, M. - Pospíšil, Jiří - Žádníková, P. - Strnad, Miroslav - Benková, E.
Root gravity response module guides differential growth determining both root bending and apical hook formation in Arabidopsis.
Development. Roč. 146, č. 17 (2019), č. článku dev175919. ISSN 0950-1991. E-ISSN 1477-9129
R&D Projects: GA MŠMT(CZ) EF16_019/0000738
Institutional support: RVO:61389030
Keywords : Apical hook * Arabidopsis * Auxin maxima * Formation stage * Green embryos * Root gravitropism
OECD category: Biochemical research methods
Impact factor: 5.611, year: 2019
Method of publishing: Open access
http://dx.doi.org/10.1242/dev.175919

The apical hook is a transiently formed structure that plays a protective role when the germinating seedling penetrates through the soil towards the surface. Crucial for proper bending is the local auxin maxima, which defines the concave (inner) side of the hook curvature. As no sign of asymmetric auxin distribution has been reported in embryonic hypocotyls prior to hook formation, the question of how auxin asymmetry is established in the early phases of seedling germination remains largely unanswered. Here, we analyzed the auxin distribution and expression of PIN auxin efflux carriers from early phases of germination, and show that bending of the root in response to gravity is the crucial initial cue that governs the hypocotyl bending required for apical hook formation. Importantly, polar auxin transport machinery is established gradually after germination starts as a result of tight root-hypocotyl interaction and a proper balance between abscisic acid and gibberellins.
Permanent Link: http://hdl.handle.net/11104/0300008