Fig. 4: Water availability regulates stress hormones.

a, Transcriptional dynamics of genes associated with ethylene and jasmonic acid synthesis and signalling. b,c, Ethylene biosynthesis reporter ACS6-VENUS (b) and jasmonic acid-response reporter JAZ10-VENUS (c) expression under conditions of high (0.75% agar) and low (2% agar) water availability. d, Regeneration frequencies after treatment with ethylene precursor (4 µM ACC) or jasmonic acid (5 µM MeJA) under intermediate-water conditions (1.5% agar) (n = 19, 20 and 17 (left to right) independent explants; mean). e, The frequency of root regeneration in ethylene mutants compared with wild type under high-water conditions (n = 10, 13, 12, 12, 16 and 12 (left to right) independent explants; ***P < 0.001; two-tailed Student’s t-test; box plot shows median (central line), mean (cross), first and third quartiles (top and bottom edges), and minimum and maximum values excluding outliers (whiskers)). f, The normalized WIC area of wild type and ethylene mutants under low-water conditions (n = 18, 19, 19, 25, 20 and 21 (left to right) independent explants; *P < 0.05; two-tailed Student’s t-test; box plot details as in e). g, The regeneration frequency in the etr1-1 mutant under intermediate-water conditions (n = 18 (wild type), 21 (etr1-1) independent explants, mean). Scale bar, 100 µm. The look-up table in b displays the signal intensity range used for b and c. Confocal experiments (b and c) were independently performed three times with similar results.