【摘要】 近期研究表明泛素化在植物胁迫响应中扮演一个关键的角色。作为泛素-蛋白酶体系统(UPS)中的关键酶,泛素E3连接酶更是在细胞的新陈代谢中起着重要的作用。本文从胡杨中克隆了一个C端含有Ring finger结构域的蛋白(152个氨基酸)编码基因(Pe RH2),经过序列比对推断该基因编码产物为泛素E3连接酶,属于Ring finger家族中的Ring-H2构型。研究显示,甘露醇胡杨苗木在255 mmol/L甘露醇胁迫下,叶片Pe RH2表达量上调。拟南芥原生质体中瞬时表达融合质粒p Yellow0029-Pe RH2的研究表明,Pe RH2蛋白定位于细胞核。以农杆菌介导法将Pe RH2转入烟草,Sq RT-PCR结果显示,Pe RH2在转基因烟草中获得过表达。在255 mmol/L甘露醇处理下,转基因烟草幼苗耐受渗透胁迫的能力高于野生型和转空载体烟草。干旱处理后,转基因烟草的叶片保水力明显高于野生型和转空载体烟草,而叶片相对电导率、MDA的含量也要低于野生型和转空载体烟草。因此,过表达Pe RH2能够提高烟草的抗旱能力。更多还原

【Abstract】 Recent studies show that ubiquitination plays a critical role in regulating plant responses to abiotic stresses. Being as a key enzyme of the ubiquitin 26 S proteasome system(UPS), ubiquitin E3 ligases mediates numerous cellular processes in plant cells. In this study, we cloned a putative Pe RH2 gene encoding ubiquitin E3 ligase from populus euphratica leaves. The Pe RH2 gene encodes a protein(152 amino acids) with a Ring finger motif located at the C-terminus. Sequence analysis suggests that Pe RH2 is a member of Ring-H2 type belong to Ring finger family. Pe RH2 was upregulated under 255 mmol/L mannitol in P. euphratica. Transient expression of the gene construct of p Yellow0029-Pe RH2 in Arabidopsis mesophyll protoplast demonstrated the nucleus loclization of the Pe RH2 protein. Through Agrobacterium-mediated method Pe RH2 was transferred into tobacco plants.Sq RT-PCR analysis showed that Pe RH2 gene was overexpressed in transgenic tobacco and two transgenic lines were obtained. Under drought treatment, the leaf water-retaining capacity(WRC) of Pe RH2-transgenic tobacco was higher than that of wild type and vector control plants. The relative electrolytic leakage and MDA contents were much lower in leaves of Pe RH2-transgenic plant. We conclude that overexpression of Pe RH2 enhance drought tolerance in tobacco.更多还原