褐藻羊栖菜水通道蛋白基因SfLIP的克隆及其在淡水浸泡下的表达分析

Cloning of a Aquaporin SfL IP from Sargassum fusiforme and Its Expression Analysis Under Fresh-Water Immersion

褐藻羊栖菜对淡水浸泡有很强的耐受能力,利用此特性,养殖户们用淡水浸泡的方法清除沙蚕等敌害生物,而对羊栖菜幼苗则无不良影响,而藻类独特的水通道蛋白在其中可能扮演重要角色。通过克隆得到了褐藻羊栖菜Sf LIP基因编码序列,其包含678 bp的开放阅读框,编码225个氨基酸,Sf LIP蛋白结构域预测表明其含有6个跨膜区域并且含有2个NPA水通道特征性单元,但其中第二NPA被NPM取代;基因结构分析发现Sf LIP基因含有5个内含子,与长囊水云的同源性很高;Sf LIP基因在淡水浸泡过程中的表达先升后降,但随着时间延长则又显著上升。上述结果表明,Sf LIP属于藻类中发现的一类新的水通道蛋白,其在羊栖菜耐受低渗胁迫中可能有种特殊的作用机制。

Due to the strong resistant ability to hypotonic stress of Sargassumfusiforme ,farmers use freshwater immersion method to remove Nereis and other harmful organisms without adverse effects on seedlings,where the unique aquaporins in algae may play important roles. By cloning,the coding sequence of SfLIP was obtained from Sorgossumfusiforme ,which contained 678 bp open reading frame ,coding 225 amino acids. SfLIP protein domain prediction showed that it contained 6 transmembrane region and 2 NPA motifs ,however,where the second one was replaced by NPM. Gene structure analysis found that SfLIP gene contained 5 introns,which showed high sequence homology to Ectocarpus siliculosus. Under freshwater immersion,SfLIP gene was first increased and then decreased ,however,as the prolongation of time,which was remarkably increased. The results indicated that SfLIP belongs to unique kind of aquaporins founded in algae ,which may have a special mechanism in the tolerance of S. fusiformeto fresh-water immersion.