摘要
以NaCl胁迫处理的拟南芥幼苗叶片为材料,用TRIzol一步法RNA提取试剂盒抽提总RNA,通过RT-PCR方法和DNA序列测定,证实获得了拟南芥Na+/H+逆向转运蛋白基因(AtNHX1)的cDNA克隆。该cDNA全长1 617 bp,包括538个氨基酸编码区和1个终止密码,具有多个物种Na+/H+逆向转运蛋白基因的高度保守序列氨氯砒嗪脒(amiloride)的结合位点(LFFIYLLPPI)。序列同源性分析结果显示,该cDNA片段与原序列的同源性高达99.75%,与同科芸薹属油菜的同源性为89.00%,但与不同科植物的同源性较低,仅为60%~70%,表明该基因在进化上存在多样性,但它们都具有氨氯砒嗪脒结合位点,对Na+具有高度专一性,对植物的耐盐性起着重要作用。
A cDNA clone encoding Na^＋/H^＋ antiporter （AtNHX1） was amplified from the total RNA extracted from leaves of A. thalian seedling under NaCl stress, done by using RT-PCR and then directly sequenced. This particular cDNA contains 1 617 bp long open reading frame （ORF） and encodes a protein of 538 amino acids. It has a high conservative sequence-binding domain of amiloride （LFFIYLLPPI）. The nucleotide sequence of AtNHX1 cDNA shared 99.75% identity with the AtNHX1 gene previously cloned from A. thalian, 89.00%identity with that of Brassica napus in the same family and 60%-70% identity with those of other families.This analysis suggested that the AtNHX1 genes are evolutionarily diversified although they all have a binding domain of amiloride and a high specificity on Na^＋ , which is of great importance in salt tolerance.
出处
《草业学报》
CSCD
2005年第6期87-93,共7页
Acta Prataculturae Sinica
基金
"863计划"(2004AA241132)
甘肃省科技攻关项目(2GS054-A41-005-01)资助
