蛋白激发子PeaT1在枯草芽胞杆菌中的分泌表达及重组菌株提高小麦抗旱和促生的作用

Extracellular expression of protein elicitor PeaT1 in Bacillus subtilis to enhance drought tolerance and wheat growth

摘要:

PeaT1是从极细链格孢菌Alternaria tenuissima中分离的一种蛋白激发子，具有促进植物生长和诱导植物产生系统获得抗性的功能，为了实现peaT1基因在枯草芽胞杆菌Bacillus subtilis中的分泌表达，增加其应用途径，从枯草芽胞杆菌基因组DNA中分别扩增获得P43启动子和nprB基因的信号肽序列，并用SOE (Splicing by over lapping extension) 方法与peaT1基因连接，将连接产物克隆到大肠杆菌-枯草芽胞杆菌穿梭表达载体pHY300-PLK上，构建了重组表达载体pHY43N-peaT1。将重组载体转化枯草芽胞杆菌WB800菌株，SDS-PAGE和Western blotting分析证实，在NprB信号肽的引导下，枯草芽胞杆菌成功分泌表达了PeaT1蛋白。构建的重组菌株能够显著增强幼苗抗旱性，提高小麦株高。

Abstract:

PeaT1, a protein elicitor from Alternaria tenuissima can promote plant growth and trigger systemic acquired resistance in plants. In order to expand the application of PeaT1, P43 promoter sequence and nprB signal peptide-encoding sequence were cloned from Bacillus subtilis 168 chromosomal DNA. The two sequences and peaT1 gene were spliced by overlapping extension. This product was cloned into the Escherichia coli-B. subtilis shuttle vector pHY300-PLK and the resultant recombinant expression vector (pHY43N- peaT1) plasmid was transformed into B. subtilis WB800. SDS-PAGE and Western blotting analysis showed that protein elicitor PeaT1 was expressed extracellularly in B. subtilis. This recombinant bacterial strain enhanced drought tolerance and promoted seedling growth in wheat.