Transmission electron micrographs of leaf mesophyll cells of the wheat cv. Sakha-94 grown under normal irrigation (a), drought alone (b), the combined application of drought and 100 µM Put as a seed primer (c) and the combined application of drought and 100 µM Put as a foliar spray (d). V vacuole, CW cell wall, SG starch grain, N nucleus, Cp chloroplast, P plastoglobuli, PM plasma membrane, Mi mitochondria