Environment sensing in spring-dispersed seeds of a winter annual Arabidopsis influences the regulation of dormancy to align germination potential with seasonal changes.
Seed dormancy cycling plays a crucial role in the lifecycle timing of many plants. Little is known of how the seeds respond to the soil seed bank environment following dispersal in spring into the short-term seed bank before seedling emergence in autumn. Seeds of the winter annual Arabidopsis ecotype Cvi were buried in field soils in spring and recovered monthly until autumn and their molecular eco-physiological responses were recorded. DOG1 expression is initially low and then increases as dormancy increases. MFT expression is negatively correlated with germination potential. Abscisic acid (ABA) and gibberellin (GA) signalling responds rapidly following burial and adjusts to the seasonal change in soil temperature. Collectively these changes align germination potential with the optimum climate space for seedling emergence. Seeds naturally dispersed to the soil in spring enter a shallow dormancy cycle dominated by spatial sensing that adjusts germination potential to the maximum when soil environment is most favourable for germination and seedling emergence upon soil disturbance. This behaviour differs subtly from that of seeds overwintered in the soil seed bank to spread the period of potential germination in the seed population (existing seed bank and newly dispersed). As soil temperature declines in autumn, deep dormancy is re-imposed as seeds become part of the persistent seed bank.
School of Life Sciences, University of Warwick, Wellesbourne Campus, Warwickshire, CV35 9EF, UK.
Steven
S
Footitt
School of Life Sciences, University of Warwick, Wellesbourne Campus, Warwickshire, CV35 9EF, UK.
Heather A
HA
Clay
School of Life Sciences, University of Warwick, Wellesbourne Campus, Warwickshire, CV35 9EF, UK.
Katherine
K
Dent
School of Life Sciences, University of Warwick, Wellesbourne Campus, Warwickshire, CV35 9EF, UK.
William E
WE
Finch-Savage
D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000254:growth & development*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005875:Gibberellins / Q000494:pharmacology; D009566:Nitrates / Q000494:pharmacology; D057445:Plant Dormancy / Q000187:drug effects / Q000235:genetics; D010937:Plant Growth Regulators / Q000378:metabolism; D012621:Seasons; D058614:Seed Dispersal / Q000187:drug effects / Q000235:genetics; D012639:Seeds / Q000187:drug effects / Q000235:genetics / Q000254:growth & development*; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics; D012987:Soil
D029681:Arabidopsis Proteins; D005875:Gibberellins; D009566:Nitrates; D010937:Plant Growth Regulators; D012987:Soil
Arabidopsis; DOG1; MOTHER OF FLOWERING TIME; dormancy cycling; hormone signalling; nitrate; soil seed bank; temperature