Mitochondrial Motility Increases in Response to Germination Cues and Leads to Increased Intermitochondrial Interaction and Fusion. Mitochondrial Motility Increases in Response to Germination Cues and Leads to Increased Intermitochondrial Interaction and Fusion. (A) Germination protocol and images of seed at the developmental stages used for experiments. Developmental stages: TR, testa rupture; ER, endosperm rupture; LR, long root; RH, root hair. L, after transfer to light; S, stratification. Bar = 200 µm. (B) Images generated using Imaris to track mitochondria in cotyledon cells over a period of 5 min. Detected mitochondria were colored green and tracks are rainbow colored according to speed (no movement is purple, and movement above 0.032 µm/s is red). Each image is representative of data captured from six seeds (total number of tracks analyzed per time point ranges from 623 to 2180). Bar = 5 µm. See Supplemental Movie 1. (C) Violin box plots of the mean speed recorded per track in nanometers/second. Box plot whiskers indicate 1.5 × IQR, and any outliers are represented by an open circle, as described by Tukey. Means are represented by a solid circle. The notch corresponds to the median ± 1.58 × IQR/√n. (D) Violin box plots of track displacement length. Plot design as in (C). (E) Violin box plots of track straightness (1 = perfectly straight). Plot design as in (C). (F) Violin box plots of numbers of interactors per track for tracks having at least one interaction between detected mitochondrial objects. Plot design as in (C). (G) Violin box plots of the rate of fusion between mitochondrial objects expressed per mitochondria. Plot design as in (C). (H) Dot plot of the percentage of mitochondria sharing a track within the 5-min tracking period. Open circles indicate percentage mitochondrial objects sharing a track in each image stack, while the solid circle indicates the mean (n = 6). The line represents the Loess regression, while the gray area corresponds to the 95% confidence interval. Gaël Paszkiewicz et al. Plant Cell 2017;29:109-128 ©2017 by American Society of Plant Biologists