【摘要】 羊草是我国重要的牧草和生态草资源,具有耐盐碱、耐旱、耐低温等特性,是天然的抗逆基因资源库。CBF/DREB属于AP2转录因子家族,在植物抗逆中发挥着重要作用。本研究克隆得到羊草LcCBF6(Leymus chinensis Crepeat binding factor 6)基因,该基因含有AP2结构域,编码245个氨基酸。氨基酸序列比对发现,LcCBF6与蒙古冰草和黑麦的CBF6蛋白的同源性分别为92%和91%。组织特异性表达模式分析表明,LcCBF6基因在羊草根、叶、种子中均有表达,且受盐胁迫诱导表达。过表达LcCBF6能显著提高转基因拟南芥的抗盐性。在盐胁迫条件下,转基因株系的绿色子叶数、根长、植株生物量以及存活率等均明显高于野生型。上述结果表明羊草LcCBF6基因在提高植物盐胁迫抗性方面发挥了重要的作用,将为牧草及重要农作物抗逆分子育种提供优异的基因资源。更多还原

【Abstract】 Chinese wild rye(Leymus chinensis) is an important forage grass in China,and is also ecologically important because it has high tolerance to saline-alkali soil,drought,and low temperature stresses. Chinese wild rye can therefore be an excellent gene pool for molecular breeding to enhance stress tolerance. CBF/DREBs belong to the AP2 transcription factor family and play an important role in plant stress resistance. In this study,the LcCBF6(L. chinensis C-repeat binding factor 6) gene was cloned. It encoded 245 amino acids and contained the AP2 domain. Amino acid sequence alignment showed that the LcCBF6 gene had high sequence conformity to its homologous proteins from Agropyron mongolicum(92%) and Secale cereale(91%). Expression analysis confirmed that LcCBF6 gene was expressed in roots,leaves and seeds,and was significantly induced by salt stress.Overexpression of LcCBF6 significantly enhanced the salt resistance of transgenic Arabidopsis thaliana. Under the salt stress,the number of green cotyledons,the root length,plant biomass and survival rate of transgenic lines were all significantly higher than in the wild type. The results suggest that the LcCBF6 gene might play an important positive role in salt stress tolerance,and be an excellent gene to utilize for enhancing stress tolerance in forages and other important crops.更多还原