Figure 2
From: Melatonin alleviates low-sulfur stress by promoting sulfur homeostasis in tomato plants

Melatonin (MT) attenuates low sulfur-induced ROS accumulation in tomato. (a) Histochemical staining of tomato leaves and roots with 3, 3′-diaminobenzidine (DAB) and 2′,7′-dichlorodihydrofluorescein diacetate (DCF), respectively; bar = 200 µm (upper panel) and bar = 50 µm (lower panel); (b) H2O2 content, (c) MDA content and (d) chloroplast ultrastructure by transmission electron microscopy (TEM) after 15 days of growth at sulfur deficient condition, bars = 0.5 µm. Fourteen-day-old tomato plants were supplied with an optimal amount of sulfur (S) or 1/10 of optimal sulfur (LS) for 15 days, and 100 µM of MT was sprayed every five days for a total of three applications. Data are presented as the means of 4 replicates. The means denoted by the same letter did not significantly differ at P < 0.05 according to a Tukey’s test.