Perata P., Matsukura C., Vernieri P., Yamaguchi J.
Nagoya University Bioscience Center, Nagoya University, Chikusa-ku, Nagoya 464-01, Japan.
Plant Cell. 1997 Dec;9(12):2197-2208. doi: 10.1105/tpc.9.12.2197.
Increasing evidence shows that sugars can act as signals affecting plant metabolism and development. Some of the effects of sugars on plant growth and development suggest an interaction of sugar signals with hormonal regulation. We investigated the effects of sugars on the induction of [alpha]-amylase by gibberellic acid in barley embryos and aleurone layers. Our results show that sugar and hormonal signaling interact in the regulation of gibberellic acid-induced gene expression in barley grains. The induction of [alpha]-amylase by gibberellic acid in the aleurone layer is unaffected by the presence of sugars, but repression by carbohydrates is effective in the embryo. [alpha]-Amylase expression in the embryo is localized to the scutellar epithelium and is hormone and sugar modulated. The effects of glucose are independent from the effects of sugars on gibberellin biosynthesis. They are not due to an osmotic effect, they are independent of abscisic acid, and only hexokinase-phosphorylatable glucose analogs are able to trigger gene repression. Overall, the results suggest the existence of an interaction between the hormonal and metabolic regulation of [alpha]-amylase genes in barley grains.
越来越多的证据表明，糖类可作为信号影响植物的新陈代谢和发育。糖类对植物生长发育的一些影响表明糖信号与激素调节之间存在相互作用。我们研究了糖类对赤霉素诱导大麦胚和糊粉层中α-淀粉酶的影响。我们的结果表明，在大麦籽粒中，糖信号和激素信号在赤霉素诱导的基因表达调控中相互作用。糊粉层中赤霉素诱导的α-淀粉酶不受糖类存在的影响，但碳水化合物在胚中具有有效的抑制作用。胚中α-淀粉酶的表达定位于盾片上皮，且受激素和糖的调节。葡萄糖的作用独立于糖类对赤霉素生物合成的影响。它们不是由于渗透作用，独立于脱落酸，只有己糖激酶可磷酸化的葡萄糖类似物能够触发基因抑制。总体而言，结果表明大麦籽粒中α-淀粉酶基因的激素调节和代谢调节之间存在相互作用。
