title: Molecular mechanisms underlying the entrance in secondary dormancy of Arabidopsis seeds.
abstract: As seasons change, dormant seeds cycle through dormant states until the environmental conditions are favourable for seedling establishment. Dormancy cycle is widespread in the plant kingdom allowing the seeds to display primary and secondary dormancy. Several reports in the last decade have focused on understanding the molecular mechanisms of primary dormancy, but our knowledge regarding secondary dormancy is limited. Here, we studied secondary dormancy induced in Arabidopsis thaliana by incubating seeds at 25 °C in darkness for 4 d. By physiological, pharmacological, expression and genetics approaches, we demonstrate that (1) the entrance in secondary dormancy involves changes in the content and sensitivity to GA, but the content and sensitivity to ABA do not change, albeit ABA is required; (2) RGL2 promotes the entrance in secondary dormancy through ABI5 action; and (3) multivariate analysis with 18 geographical and environmental parameters of accession collection place suggests that temperature is an important variable influencing the induction of secondary dormancy in nature.
authors.affiliation: IFEVA, Facultad de Agronomía, Universidad de Buenos Aires y Consejo Nacional de Investigaciones Científicas y Técnicas, Av. San Martín 4453, Ciudad de Buenos Aires, C1417DSE, Argentina.
authors.forename: Silvia E
authors.initials: SE
authors.lastname: Ibarra
authors.affiliation: IFEVA, Facultad de Agronomía, Universidad de Buenos Aires y Consejo Nacional de Investigaciones Científicas y Técnicas, Av. San Martín 4453, Ciudad de Buenos Aires, C1417DSE, Argentina.
authors.forename: Rocío S
authors.initials: RS
authors.lastname: Tognacca
authors.affiliation: Centre for Novel Agricultural Products (CNAP), Department of Biology, University of York, Wentworth Way, Heslington, York, YO10 5DD, UK.
authors.forename: Anuja
authors.initials: A
authors.lastname: Dave
authors.affiliation: Centre for Novel Agricultural Products (CNAP), Department of Biology, University of York, Wentworth Way, Heslington, York, YO10 5DD, UK.
authors.forename: Ian A
authors.initials: IA
authors.lastname: Graham
authors.affiliation: IFEVA, Facultad de Agronomía, Universidad de Buenos Aires y Consejo Nacional de Investigaciones Científicas y Técnicas, Av. San Martín 4453, Ciudad de Buenos Aires, C1417DSE, Argentina.
authors.forename: Rodolfo A
authors.initials: RA
authors.lastname: Sánchez
authors.affiliation: IFEVA, Facultad de Agronomía, Universidad de Buenos Aires y Consejo Nacional de Investigaciones Científicas y Técnicas, Av. San Martín 4453, Ciudad de Buenos Aires, C1417DSE, Argentina.
authors.forename: Javier F
authors.initials: JF
authors.lastname: Botto
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics* / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D018525:Germination; D005875:Gibberellins / Q000378:metabolism; D057445:Plant Dormancy / Q000235:genetics*; D010937:Plant Growth Regulators / Q000378:metabolism*; D012621:Seasons; D012639:Seeds / Q000235:genetics* / Q000502:physiology; D013696:Temperature; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: C409743:ABI5 protein, Arabidopsis; D029681:Arabidopsis Proteins; D050976:Basic-Leucine Zipper Transcription Factors; D005875:Gibberellins; D010937:Plant Growth Regulators; C450823:RGL2 protein, Arabidopsis; D014157:Transcription Factors; D000040:Abscisic Acid
keywords: ABA; GA; natural variation; primary dormancy; secondary dormancy