8 research outputs found
The chitinase C gene PsChiC from Pseudomonas sp. and its synergistic effects on larvicidal activity
The chitinase C gene PsChiC from Pseudomonas sp. and its synergistic effects on larvicidal activity
Pseudomonas sp. strain TXG6-1, a chitinolytic gram-negative bacterium, was isolated from a vegetable field in Taixing city, Jiangsu Province, China. In this study, a Pseudomonas chitinase C gene (PsChiC) was isolated from the chromosomal DNA of this bacterium using a pair of specific primers. The PsChiC gene consisted of an open reading frame of 1443 nucleotides and encoded 480 amino acid residues with a calculated molecular mass of 51.66 kDa. The deduced PsChiC amino acid sequence lacked a signal sequence and consisted of a glycoside hydrolase family 18 catalytic domain responsible for chitinase activity, a fibronectin type III-like domain (FLD) and a C-terminal chitin-binding domain (ChBD). The amino acid sequence of PsChiCshowed high sequence homology (> 95%) with chitinase C from Serratia marcescens. SDS-PAGE showed that the molecular mass of chitinase PsChiC was 52 kDa. Chitinase assays revealed that the chitobiosidase and endochitinase activities of PsChiCwere 51.6- and 84.1-fold higher than those of pET30a, respectively. Although PsChiC showed little insecticidal activity towards Spodoptera litura larvae, an insecticidal assay indicated that PsChiC increased the insecticidal toxicity of SpltNPV by 1.78-fold at 192 h and hastened death. These results suggest that PsChiC from Pseudomonas sp. could be useful in improving the pathogenicity of baculoviruses
Multiple infection frequencies of facultative symbionts in female and male <i>B. tabaci</i>.
<p>Different letters represent different symbiont combinations: HCW, <i>Hamiltonella</i>, <i>Cardinium</i> and <i>Wolbachia</i>; HC, <i>Hamiltonella</i> and <i>Cardinium</i>; HR, <i>Hamiltonella</i> and <i>Rickettsia</i>; HW, <i>Hamiltonella</i> and <i>Wolbachia</i>; and CW, <i>Cardinium</i> and <i>Wolbachia</i>.</p><p><i>P</i><0.01,</p><p><i>P</i><0.0001.</p
Infection frequencies of the facultative symbiont <i>Hamiltonella</i> in female and male <i>B. tabaci</i>.
<p><i>Hamiltonella</i> was the predominant facultative symbiont identified in the 5 populations, and the overall infection frequency of <i>Hamiltonella</i> in females was significantly higher than that in males, whereas infection frequencies did not differ between females and males in every population; in two populations of the whiteflies, more females than males harbored <i>Hamiltonella</i>, whereas in the other three populations, the <i>Hamiltonella</i> infection frequencies of females and males were at similar levels.</p
Nucleotide sequence of the primers that were used in the present study.
<p>Nucleotide sequence of the primers that were used in the present study.</p
Rates of female and male viruliferous whiteflies.
<p>The TYLCV infection was sexual different, and the rate of viruliferous whiteflies in females was significantly higher than that in males.</p
Infection frequencies of the obligate symbiont in female and male <i>B. tabaci</i>.
<p>Columns indicate a female-biased obligate symbiont, <i>P. aleyrodidarum</i> infection in the 5 populations of whiteflies; and the infection rate in females in each population was all significantly higher than that in males. *<i>P</i><0.05, **<i>P</i><0.01, and ***<i>P</i><0.0001.</p