Understanding the gravitropic signal transduction pathway through the analysis of new Arabidopsis mutants.
The gravitropic response of plants can be divided into three steps: detection, transduction, and asymmetric growth. Of these the second is that on which we have the smallest knowledge. Even though we have in fact some support for a redistribution of auxin as the agent of the graviresponse (Cholodny-Went hypothesis), we still lack of a precise knowledge about the many steps which precede and follow auxin redistribution. We thereore today dispose of the powerful new techniques of molecular genetics, that can help us in dissecting the pathway. By these techniques, as is known, already a number of gravitropic mutants have been isolated in the model plant Arabidopsis, and, in addition, some of the genes involved have been cloned. These findings already permit some speculation about the gravitropic pathway, even though we still are far from an understanding of the process. With the aim thus of obtaining the information we need to elucidate the gravitropic pathway, in the last two years, we performed a screening of some significant collections of Arabidopsis mutants, isolating individuals disturbed in root gravitropism, and starting to clone the involved genes.
Migliaccio
F
F
Institute of Plant Biochemistry and Ecophysiology, Consiglio Nazionale delle Ricerche, Monterotondo, Italy.
Ferrari
S
S
Piconese
S
S
D017360:Arabidopsis / Q000235:genetics* / Q000502:physiology; D003001:Cloning, Molecular; D017343:Genes, Plant; D018522:Gravitropism / Q000235:genetics / Q000502:physiology*; D009154:Mutation; D010937:Plant Growth Regulators / Q000502:physiology; D018517:Plant Roots / Q000235:genetics* / Q000502:physiology; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology*
D010937:Plant Growth Regulators