Ecotoxicological test to assess effects of herbicides on spore germination of Rhizophagus clarus and Gigaspora albida

Background: Genome sequence analysis (GenBank access No.: FN667742.1) shows that Xenorhabdus nematophila ATCC19061 contains one gene (Xn-cbp) encoding chitin binding protein (Xn-CBP). Objective: The present work aims to clarify the characteristics and function of Xn-CBP from X. nematophila HB310. Methods: In this study, the Xn-cbp gene was cloned and expressed in Escherichia coli BL21 (DE3). Substrate binding assays were performed to explain the ability of Xn-CBP combined with the polysaccharide. The insecticidal toxicity of Xn-CBP against the second-instar larvae of Helicoverpa armigera was determined by feeding method. Besides, the antifungal activity of Xn-CBP against Coniothyrium diplodiella, Verticillium dahlia, and Fusarium oxysporum was tested by spore germination assay and hyphal extension assay. Results: Xn-CBP encoded 199 amino acids with a calculated mass of 28 kDa, which contained a signal peptide and a chitin binding domain. The Bmax and Kd values of Xn-CBP to colloidal chitin were 2.46 and 4.08, respectively. Xn-CBP had insecticidal activity against the H. armigera with a growth inhibition rate of 84.08%. Xn-CBP had the highest spore germination inhibitory effect on C. diplodiella with the inhibition rate of 83.11%. The hyphal growth inhibition rate of Xn-CBP to F. oxysporum, 41.52%, was higher than the other two fungi. Conclusion: The Xn-CBP had the highest binding ability to colloidal chitin and it showed insecticidal activity and antifungal activity. The present study laid a foundation for further exploitation and utilization of X. nematophila.

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Tree Ferns in the Interior and at the Edge of a Mexican Cloud Forest Remnant: Spore Germination and Sporophyte Survival and Establishment1

Biotropica ◽

10.1111/j.1744-7429.1999.tb00118.x ◽

1999 ◽

Vol 31 (1) ◽

pp. 83-88

Author(s):

N. Bernabe ◽

G. Williams-Linera ◽

M. Palacios-Rios

Keyword(s):

Spore Germination ◽

Cloud Forest ◽

Tree Ferns ◽

Forest Remnant

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Predicting the Structure and Dynamics of Membrane Protein GerAB from Bacillus subtilis

International Journal of Molecular Sciences ◽

10.3390/ijms22073793 ◽

2021 ◽

Vol 22 (7) ◽

pp. 3793

Author(s):

Sophie Blinker ◽

Jocelyne Vreede ◽

Peter Setlow ◽

Stanley Brul

Keyword(s):

Bacillus Subtilis ◽

Membrane Protein ◽

Spore Germination ◽

Structural Information ◽

Transmembrane Protein ◽

Homology Modelling ◽

Water Channel ◽

Md Simulations ◽

Integral Membrane Protein ◽

Starting Point

Bacillus subtilis forms dormant spores upon nutrient depletion. Germinant receptors (GRs) in spore’s inner membrane respond to ligands such as L-alanine, and trigger spore germination. In B. subtilis spores, GerA is the major GR, and has three subunits, GerAA, GerAB, and GerAC. L-Alanine activation of GerA requires all three subunits, but which binds L-alanine is unknown. To date, how GRs trigger germination is unknown, in particular due to lack of detailed structural information about B subunits. Using homology modelling with molecular dynamics (MD) simulations, we present structural predictions for the integral membrane protein GerAB. These predictions indicate that GerAB is an α-helical transmembrane protein containing a water channel. The MD simulations with free L-alanine show that alanine binds transiently to specific sites on GerAB. These results provide a starting point for unraveling the mechanism of L-alanine mediated signaling by GerAB, which may facilitate early events in spore germination.

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Mitochondrial biogenesis during fungal spore germination. Catalytic activity, composition, and subunit biosynthesis of oligomycin-sensitive ATPase in Botryodiplodia.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(19)68942-8 ◽

1981 ◽

Vol 256 (14) ◽

pp. 7166-7172

Author(s):

H. Wenzler ◽

R. Brambl

Keyword(s):

Catalytic Activity ◽

Mitochondrial Biogenesis ◽

Spore Germination ◽

Fungal Spore

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Homogenate Extraction of Dihydroartemisinin from Artemisia Hedinii and Its Antifungal Activity

Journal of AOAC International ◽

10.1093/jaoacint/qsab010 ◽

2021 ◽

Author(s):

Cong You ◽

Jun Yu ◽

Guangjiong Qin ◽

JinPeng Yang ◽

Chunlei Yang ◽

...

Keyword(s):

Antifungal Activity ◽

Crude Extract ◽

Spore Germination ◽

Alternaria Alternata ◽

Low Cost ◽

Pathogenic Fungi ◽

Extraction Yield ◽

Optimal Conditions ◽

Extraction Technology ◽

Homogenate Extraction

Abstract Background Artemisia hedinii is a well-known traditional Chinese medicine. It can be used to extract dihydroartemisinin (DHA). Objective The purpose of this study was to explore the optimal conditions for the homogenate extraction of DHA from A. hedinii and the antifungal activity of DHA. Methods In this study, single factor experiments and response surface method were used to determine the optimal extraction conditions of crude extract and DHA, the method of spore germination was used to study the antifungal activity of DHA to Alternaria alternata. Result The optimal conditions were found as fellow: ratio of liquid to material 22 mL/g; Extraction time 60 s; soaking time 34 min. Under these conditions, extraction yield of DHA was (1.76 ± 0.04%). When the concentration of crude extract were 0.5 and 8 mg/mL, the spore germination inhibition rates of Alternaria alternata were (17.00 ± 2.05%) and (92.56 ± 2.01%), which were 3.34 and 1.15 times that of DHA standard, respectively. Conclusion Homogenate extraction technology is a fast and efficient method to extract DHA from A. hedinii. The crude extract has significant antifungal activity against A. alternata with low cost, which provides a possibility for the use of DHA in the prevention and treatment of plant pathogenic fungi. Highlights The optimum conditions of the extraction of DHA from A. hedinii by homogenate extraction were obtained. DHA has antifungal activity against A. alternata. Compared with pure DHA, the crude extract has stronger antifungal activity against A. alternata.

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