【摘要】 探究马铃薯基因StEXLB1a的表达模式和功能，为后续马铃薯病害的抗性研究提供理论依据。在东北农业大学植物资源与分子生物学实验室前期研究基础上，以马铃薯大西洋品种为材料，克隆了StEXLB1a基因并对其进行了生物信息学、表达模式和抗病功能初步分析。结果表明:StEXLB1a基因cDNA全长序列768bp，编码255个氨基酸，注释显示其属于扩展蛋白家族基因。亚细胞定位显示，该蛋白定位于细胞壁上。在马铃薯不同组织中，StEXLB1a基因在叶中表达量最高，根和地上茎其次，在花和块茎中最低。在激素(吲哚乙酸、赤霉素、脱落酸)、逆境(高温、低温、盐、干旱)和真菌病害干腐病(燕麦镰孢菌)、细菌病害软腐病(胡萝卜软腐欧文氏菌)及青枯病(茄科雷尔氏菌)等多种胁迫处理下，StEXLB1a基因的表达量在各个处理中均有显著变化。获得过表达转基因马铃薯植株后，接种干腐病致病菌燕麦镰孢菌，转基因比野生型植株叶片受到病菌的侵染严重。过表达植株中的活性氧清除系统相关酶活性发生显著变化，POD、SOD活性受到抑制，MDA含量高于野生型植株，植株受损程度加重。分析结果表明，过表达StEXLB1a的转基因马铃薯植株相较野生型对干腐病的抗病性下降。更多还原

【Abstract】 To explore the expression pattern of potato gene StEXLB1a and provide a theoretical basis for the resistance to potato disease,based on the previous research of the Laboratory of Plant Resources and Molecular Biology at Northeast Agricultural University,the study using the Atlantic variety of potato as material,cloned the StEXLB1a gene,and preliminarily analyzed its bioinformatics,expression pattern,and disease resistance. The results showed that the full-length cDNA sequence of StEXLB1a gene was 768 bp,encoding 255 amino acids. The annotation indicated that it belonged to the extend protein family genes. Subcellular localization showed that the protein was localized to the cell wall. Among different tissues of potato,StEXLB1a gene expression was highest in leaves,followed by roots and stems,and lowest in flowers and tubers. The expression level of StEXLB1a gene changed significantly under various stress treatments,such as hormone(indoleacetic acid,gibberellin,abscisic acid),stress(high temperature,low temperature,salt,drought),fungal disease dry rot(Fusarium avenaceum),bacterial disease soft rot(Erwinia carotovora subsp,Ecc) and bacterial wilt(Ralstonia solanacearum,RS). The overexpressed transgenic potato plants were inoculated with the dry rot pathogen Fusarium avenaceum,and the transgenic plants were more seriously infected than the wild-type plants. The enzyme activities of active oxygen scavenging system in overexpressed plants were significantly changed,POD and SOD activities were inhibited,MDA content was higher than that of wild-type plants,and the damage degree of plants was aggravated. The results showed that transgenic potato plants with overexpression of StEXLB1a had lower resistance to dry rot than those with wild type.更多还原