It has been shown that gibberellin (GA) perception is part of root-to-shoot communication in plants during drought. However, it is not clear how GA content interferes with long-distance drought response signaling. Thus, in this study, the tomato (Solanum lycopersicum L.) cultivar Micro-Tom (MT) was treated with 50 mM acid gibberellic, while the control plants were sprayed with water. After treatment, tomato plants were reciprocally grafted (i.e., MT/MT, MT + GA/MT + GA, MT + GA/MT, MT/MT + GA; within each pair, the first indicates the scion, and the second indicates the rootstock). Therefore, to evaluate the role of GA in root-to-shoot communication during drought stress, plants were grown under well-watered or drought conditions. Height, leaf and root area, dry weight, malondialdehyde content, relative water content and stomatal conductance were measured. It was verified that the MT + GA/MT and MT + GA/MT + GA plants were taller than the grafted plants without GA treatment. Furthermore, non-treated plants (MT/MT) exhibited a reduction in root area due to water-deficit. Regarding water relations, under drought, the greatest reduction in stomatal conductance was observed in plants grafted onto rootstocks treated with GA, which favored the maintenance of an increased relative water content. This demonstrates an important role of GA in root-to-shoot communication to induce stomatal closure during water-deficit conditions.

已经表明，赤霉素 (GA) 感知是干旱期间植物根到芽通信的一部分。然而，目前尚不清楚 GA 含量如何干扰长距离干旱响应信号。因此，在本研究中，番茄（Solanum lycopersicumL.) 栽培品种 Micro-Tom (MT) 用 50 mM 酸性赤霉素处理，而对照植物用水喷洒。处理后，番茄植株相互嫁接（即MT/MT、MT+GA/MT+GA、MT+GA/MT、MT/MT+GA；每对中，第一个表示接穗，第二个表示接穗）砧木）。因此，为了评估 GA 在干旱胁迫期间根与芽交流中的作用，植物在浇水充足或干旱的条件下生长。测量高度、叶和根面积、干重、丙二醛含量、相对含水量和气孔导度。经证实，MT + GA/MT 和 MT + GA/MT + GA 植株比未经 GA 处理的嫁接植株高。此外，未经处理的植物 (MT/MT) 由于缺水而表现出根部面积的减少。关于水的关系，在干旱条件下，在嫁接在用 GA 处理的砧木上的植物中观察到气孔导度的最大降低，这有利于维持增加的相对含水量。这表明 GA 在缺水条件下诱导气孔关闭的根与芽通信中的重要作用。