Lahuta Lesław B, Pluskota Wioletta E, Stelmaszewska Joanna, Szablińska Joanna
University of Warmia and Mazury in Olsztyn, Department of Plant Physiology, Genetics and Biotechnology, ul. Oczapowskiego 1A/103, 10-718 Olsztyn, Poland.
University of Warmia and Mazury in Olsztyn, Department of Plant Physiology, Genetics and Biotechnology, ul. Oczapowskiego 1A/103, 10-718 Olsztyn, Poland.
J Plant Physiol. 2014 Sep 1;171(14):1306-14. doi: 10.1016/j.jplph.2014.04.012. Epub 2014 May 17.
The exposition of 7-day-old pea seedlings to dehydration induced sudden changes in the concentration of monosaccharides and sucrose in epicotyl and roots tissues. During 24h of dehydration, the concentration of glucose and, to a lesser extent, fructose in seedling tissues decreased. The accumulation of sucrose was observed in roots after 4h and in epicotyls after 8h of stress. Epicotyls and roots also began to accumulate galactinol and raffinose after 8h of stress, when small changes in the water content of tissues occurred. The accumulation of galactinol and raffinose progressed parallel to water withdrawal from tissues, but after seedling rehydration both galactosides disappeared. The synthesis of galactinol and raffinose by an early induction (during the first hour of treatment) of galactinol synthase (PsGolS) and raffinose synthase (PsRS) gene expression as well as a later increase in the activity of both enzymes was noted. Signals possibly triggering the induction of PsGolS and PsRS gene expression and accumulation of galactinol and raffinose in seedlings are discussed.
将7日龄豌豆幼苗置于脱水环境中，会导致上胚轴和根组织中单糖和蔗糖浓度突然发生变化。在脱水24小时期间，幼苗组织中葡萄糖的浓度下降，果糖浓度下降幅度较小。胁迫4小时后，根部开始积累蔗糖，胁迫8小时后，上胚轴开始积累蔗糖。胁迫8小时后，当组织含水量发生微小变化时，上胚轴和根也开始积累肌醇半乳糖苷和棉子糖。肌醇半乳糖苷和棉子糖的积累与组织水分流失同步进行，但幼苗复水后，这两种半乳糖苷都消失了。研究发现，通过早期诱导（处理的第一小时内）肌醇半乳糖苷合成酶（PsGolS）和棉子糖合成酶（PsRS）基因表达，以及随后这两种酶活性的增加，从而合成肌醇半乳糖苷和棉子糖。本文还讨论了可能触发豌豆幼苗中PsGolS和PsRS基因表达诱导以及肌醇半乳糖苷和棉子糖积累的信号。
