Temperature promotes graft formation by elevating auxin response. (A) Proportion of grafted Arabidopsis pSUC2::GFP scions with fluorescing Col-0 rootstocks after petiole NPA treatments and recovered at 20°C or 27°C [±standard error of a proportion (s.e.p.); n=50 plants per treatment]. NPA plaster (arrowhead) and graft junction (dashed line) indicated. (B) Signal intensity of auxin-responsive pDR5::GFP signal at the graft junction 48 h after grafting (HAG) recovered at 20°C or 27°C (mean±s.d. of three experiments, each ≥15 plants per temperature treatment). Dashed lines indicate the graft junction. (C) Proportion of grafted bdl-2 or wild-type Arabidopsis that transported CFDA to the rootstock 3-4 DAG and recovered at 20°C or 27°C (±s.e.p.; n=30 plants per temperature per time point). (D) Proportion of three genotype grafts with fluorescent rootstocks (±s.e.p.; n=indicated on plot). The white and black dashed lines indicate sites of cotyledon and hypocotyl grafting, respectively. *P<0.05, **P<0.01, ***P<0.001; Fisher's exact test (A,C,D) or unpaired two-tailed Student's t-test (B) compared with 20°C. Scale bars: 1 mm (A,D); 100 μm (B).