Extended Data Fig. 1: Methodology for PDLP growth analysis, their reliability as fiducial marks, and their usage in lobing segments.

Growth dependent separation of PDLP puncta pairs along an example segment. a, Using the plasma-membrane marker segments were traced at the anticlinal/outer-periclinal junction. b-c, Segment straightening followed by re-slicing produces a face-view of the anticlinal wall. d, Non-overlapping PDLPs including manually labeled 3-way-junctions were tracked over time. e, PDLP-pair distance is used to obtain sub-segmental growth rates from linear fit models over the time course. f, Sub-segmental elemental growth rates mapped onto the initial segment shape. PDLPs are stable features in the anticlinal wall and their displacement reflects localized diffuse growth. g-i, Cold-treated PDLP3:GFP; PIP2:mCherry seedlings were imaged at 4-hour intervals. j-k, Normalized signal intensity plots and overlapping peaks from PDLP3 particles of the two segments (g-i) at all 3 time-points. l, Boxplots of measured sub-segmental growth rates of cold-treated (CT) and room temperature (RT) grown seedlings. Center lines show the medians; box limits indicate the 25th and 75th percentiles as determined by R software; whiskers extend 1.5 times the interquartile range from the 25th and 75th percentiles, outliers are represented by dots. n = 14, 38 sub-segments from 3 and 9 independent segments respectively. Sub-segmental growth rates from lobing segments. m-o, Plots of normalized segment length at lobe detection (gray outline) and final (black outline) time-points color coded for normalized percent growth rate per hour. Cyan and green arrowheads mark the location of newly and established lobes respectively (Top panel). Perimeter to center of mass plots highlight warping regions between lobe detection and final timepoint. Scale bar = 5 µm (a-d), 10 µm (g-i).