Chen Lin, Jiang Huang, Cheng Qipeng, Chen Junpeng, Wu Gaobing, Kumar Ashok, Sun Ming, Liu Ziduo
State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430 070, China.
State Key Laboratory of Agricultural Microbiology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
Sci Rep. 2015 Sep 24;5:14395. doi: 10.1038/srep14395.
Nematodes are known to be harmful to various crops, vegetables, plants and insects. The present study reports that, chitin upregulates the activity of chitinase (20%) and nematicidal potential (15%) of Pseudomonas aeruginosa. The chitinase gene (pachi) from P. aeruginosa was cloned, and its nematicidal activity of pachi protein against Caenorhabditis elegans was studied. The mortality rate induced by pachi increased by 6.3-fold when in association with Cry21Aa from Bacillus thuringiensis. Pachi efficiently killed C. elegans in its native state (LC50 = 387.3 ± 31.7 μg/ml), as well as in association with Cry21Aa (LC50 = 30.9 ± 4.1 μg/ml), by degrading the cuticle, egg shell and intestine in a relatively short time period of 24 h. To explore the nematidal potential of chitinase, six fusion proteins were constructed using gene engineering techniques. The CHACry showed higher activity against C. elegans than others owing to its high solubility. Notably, the CHACry showed a synergistic factor of 4.1 versus 3.5 a mixture [1:1] of pachi and Cry21Aa. The present study has identified eco-friendly biological routes (e.g., mixed proteins, fusion proteins) with potent nematicidal activity, which not only can help to prevent major crop losses but also strengthen the agro-economy and increase gross crop yield.
已知线虫对各种农作物、蔬菜、植物和昆虫有害。本研究报告称，几丁质可上调铜绿假单胞菌的几丁质酶活性（20%）和杀线虫潜力（15%）。克隆了铜绿假单胞菌的几丁质酶基因（pachi），并研究了pachi蛋白对秀丽隐杆线虫的杀线虫活性。当与苏云金芽孢杆菌的Cry21Aa联合使用时，pachi诱导的死亡率提高了6.3倍。pachi在24小时的相对短时间内通过降解角质层、卵壳和肠道，有效地杀死了处于天然状态的秀丽隐杆线虫（LC50 = 387.3 ± 31.7 μg/ml），以及与Cry21Aa联合使用时的秀丽隐杆线虫（LC50 = 30.9 ± 4.1 μg/ml）。为了探索几丁质酶的杀线虫潜力，使用基因工程技术构建了六种融合蛋白。由于其高溶解性，CHACry对秀丽隐杆线虫的活性高于其他蛋白。值得注意的是，与pachi和Cry21Aa的混合物[1:1]相比，CHACry的协同因子为4.1，而后者为3.5。本研究确定了具有强大杀线虫活性的生态友好型生物途径（如混合蛋白、融合蛋白），这不仅有助于防止主要作物损失，还能加强农业经济并提高作物总产量。
