Centro de Biotecnología y Genómica de Plantas (UPM-INIA), Escuela Técnica Superior de Ingenieros Agrónomos, Campus de Montegancedo, Universidad Politécnica de Madrid, Pozuelo de Alarcón, Madrid, 28223, Spain.
Planta. 2011 Aug;234(2):391-403. doi: 10.1007/s00425-011-1408-x. Epub 2011 Apr 20.
Genes encoding two new isoforms of sucrose synthase from barley, HvSs3 and HvSs4, have been characterised and their expression patterns compared with those previously described for HvSs1 and HvSs2, in different organs and during seed maturation and germination. Their response to several abiotic stimuli has also been investigated in leaves: HvSs1 is up-regulated by anoxia and HvSs3 by water deprivation while no response is observed to 150 mM NaCl treatment; HvSs1 and HvSs3 are also induced by cold temperatures. Using translational fusions and transient expression analyses, the four isozymes have been localised not only to the cytoplasm but also along several cytoplasmic tracks and at the inner side of the cell membrane; besides, HvSS1 is also associated with mitochondria, a localisation that has been predicted in silico with the TargetP and Predotar programmes. These data suggest distinct although partially overlapping roles, for the four barley sucrose synthase isoforms, in the channelling of carbon towards different metabolic pathways within the cell.
已鉴定出编码大麦中蔗糖合酶两种新同工型（HvSs3 和 HvSs4）的基因，并比较了它们在不同器官以及种子成熟和萌发过程中的表达模式，与先前描述的 HvSs1 和 HvSs2 的表达模式进行了比较。还在叶片中研究了它们对几种非生物胁迫的反应：缺氧上调 HvSs1，水分胁迫上调 HvSs3，而 150 mM NaCl 处理没有反应；冷温也诱导 HvSs1 和 HvSs3。使用翻译融合和瞬时表达分析，四种同工酶不仅定位于细胞质，还定位于多个细胞质轨道和细胞膜内侧；此外，HvSS1 还与线粒体相关，这一定位是通过 TargetP 和 Predotar 程序在计算机上预测的。这些数据表明，大麦蔗糖合酶四种同工型在细胞内将碳导向不同代谢途径方面具有不同但部分重叠的作用。
