Arabidopsis Transformation and Growth

All mutants used are in the Columbia (Col) wild-type accession of Arabidopsis thaliana. The ddm1-2 allele was described before [33] (link). A new lhp1 allele, lhp1-6, was identified in the SALK T-DNA insertion mutant collection (SALK_011762). LHP1 and lhp1-7 cDNAs were cloned into vector pK7FWG2 [34] (link), which was used to transform plants by floral dip with Agrobacterium tumefaciens (strain GV3101). Seeds were germinated on sterile basal salts Murashige and Skoog (MS) medium (Duchefa, Brussels, Belgium), and plants were analyzed on plates or transferred to soil 10 days after germination. Alternatively, seeds were directly sown on soil. Plants were kept in Conviron growth chambers with mixed cold fluorescent and incandescent light (110 to 140 µmol m⁻² s⁻¹, 21±2°C) under long day (LD, 16h light) or short day (SD, 8h light) photoperiods or were alternatively raised in green houses.