Fig. 4: RLP4s contribute to directional growth control.
From: A self-regulatory cell-wall-sensing module at cell edges controls plant growth
a,b, CLSM maximum-intensity projections of lateral root epidermal meristem cells expressing YFP–RAB-A5c in the wild-type (a) or rlp4 rlp4-l1 (b) background. The cell wall was stained with propidium iodide (PI). Representative images from one of three independent experiments are shown. c–f, Lateral roots from wild-type and rlp4 rlp4-l1 plants grown for three days on DMSO or 250 nM oryzalin (Ory). g, Violin plots of the mean maximum diameter of lateral roots from plants grown for three days on DMSO or 250 nM oryzalin like those shown in c–f or S6F. N for DMSO and oryzalin for each genotype were 37 and 34 (wild type), 35 and 42 (rlp4 rlp4-l1), 36 and 37 (rlp4 rlp4-l1 pRLP4::RLP4–GFP) and 33 and 38 (rlp4 rlp4-l1 pRLP4-L1::RLP4-L1–GFP). The difference in diameter (%) between DMSO and oryzalin treatments for each genotype is noted above the respective columns. Relative diameter increased significantly more in response to oryzalin treatment in rlp4 rlp4-l1 than in the wild type (P = 0.000007), which could be fully rescued by introducing pRLP4::RLP4–GFP (P = 1) or pRLP4-L1::RLP4-L1–GFP (P = 1) into the rlp4 rlp4-l1 background. The letters indicate significant differences in relative root diameter increase (P < 0.05; two-way ANOVA and post-hoc Tukey test). Representative results from one of three independent experiments are shown. See Methods for an explanation of the violin plots. h–k, CLSM maximum-intensity projections of lateral roots expressing pRPS5a»Dex»secRFP–RLP4sΔECD three days after transfer to DMSO or 10 µM Dex. The cell wall was stained with propodium iodide. l, Violin plots of the mean maximum diameter of lateral roots from seedlings expressing pRPS5a»Dex»secRFP–RLP4sΔECD grown on 250 nM oryzalin and/or 1 µM Dex or the equivalent quantity of DMSO for three days. N for DMSO, oryzalin, Dex and Dex oryzalin, respectively, were 30, 39, 18 and 34 (RLP4ΔECD); and 27, 37, 28 and 34 (RLP4-L1ΔECD). Relative diameter increases were significantly different for oryzalin treatments in the presence versus absence of Dex (*P = 0.038,**P = 0.012; two-way ANOVA and post-hoc Tukey test). Representative results from one of three independent experiments are shown. See Methods for an explanation of the violin plots. Scale bars, 5 µm (a,b), 50 µm (h–k) or 100 µm (c–f).
