【摘要】 【目的】筛选巨桉金属耐受蛋白基因EgMTP6,分析其生物信息学特征、亚细胞定位、锌转运功能和表达模式，揭示丛枝菌根真菌、锌、磷与EgMTP6的相互关系，探究其在缓解锌胁迫中的作用。【方法】通过生物信息学分析，得到EgMTP6的核苷酸和氨基酸序列特征。利用农杆菌注射烟草叶表皮细胞分析EgMTP6的亚细胞定位，酵母突变体互补分析EgMTP6转运锌的功能。利用荧光定量PCR技术，分析锌（ZnSO₄）、磷（NaH₂PO₄）和异形根孢囊霉对EgMTP6表达模式的影响。【结果】基因预测显示：EgMTP6包含一个长度为1 524bp的开放阅读框，编码507个氨基酸，包含12个外显子和11个内含子。结构预测显示：EgMTP6蛋白氨基端位于膜内侧，羧基端位于膜外侧，包含5个跨膜螺旋和HD-HD基序。系统进化分析表明：EgMTP6属于Group6,归为Fe/Zn-CDF类群。多序列比对发现，MTP6含有亚铁离子外排泵结构（Ferrous-iron efflux pump, FieF）。亚细胞定位显示EgMTP6定位在内质网，酵母突变体互补表明EgMTP6是锌转运蛋白。荧光定量结果说明：EgMTP6的表达不受锌浓度影响，但受高浓度磷和异形根孢囊霉诱导。【结论】EgMTP6属于Fe/Zn-CDF类群，参与锌的转运，表达量不受锌浓度影响，高浓度磷处理和接种异形根孢囊霉时表达量显著提高。EgMTP6在分子特征和功能方面的研究有助于进一步探讨该基因在巨桉菌根耐受锌胁迫时的功能。更多还原

【Abstract】 【Objective】Eucalyptus can tolerate the heavy metal toxicity tosome extent, in which metal tolerance proteins play an important role. In this study, we screened a metal tolerance protein gene EgMTP6 from Eucalyptus grandis and analyzed its bioinformatics characteristics, subcellular localization, zinc transport function and expression pattern, in order to reveal the relationship between arbuscular mycorrhizal fungi, zinc, phosphorus and EgMTP6, and to explore the role of EgMTP6 in alleviating zinc stress.【Method】Through bioinformatics analyses, the gene nucleotide and amino acid sequence characteristics of EgMTP6 were obtained. Subcellular localization of EgMTP6 was analyzed by expressing EgMTP6 inepidermal cells of tobacco leaves, and the zinc transport function was analyzed by yeast mutant complementation. The effects of zinc（ZnSO₄）, phosphorus（NaH₂PO₄） and Rhizophagus irregularis on the expression of EgMTP6 were analyzed by qRT-PCR.【Result】In this study, bioinformatics analyses displayed that EgMTP6 contained an open reading frame in a length of 1 524 bp, which encoded 507 amino acids, including 12 exons and 11 introns. The tructural prediction showed that the N-terminal of EgMTP6 protein was located in the cytoplasm and the C-terminal was located in the extracellular. The protein contained five transmembrane domains and the HD-HD motif. Phylogenetic analysis showed that EgMTP6 was in Group 6 and belonged to Fe/Zn-CDF. Multiple-sequence alignment showed that MTP6 contained FieF domain（Ferrous-iron efflux pump, FieF）. Subcellular localization analysis of tobacco leaves illustrated that EgMTP6 was located in the endoplasmic reticulum. Yeast mutant complementation showed that EgMTP6 was a zinc transporter. Fluorescence quantitative results showed that the expression of EgMTP6 was not affected byzinc, but induced by high concentration of phosphorus, and R. irregularis.【Conclusion】EgMTP6 belongs to Fe/Zn-CDFgroup andit is involved in the zinc transport. Its expression is unaffected by zinc concentration, but is induced by high concentration of phosphorus, and R. irregularis. This investigations on molecular characteristics and function of EgMTP6 will be helpful to future studies on the molecular mechanism of heavy metal tolerance of arbuscular mycorrhizal in Eucalyptus grandis.更多还原