scholarly journals The ACE Genes in Aphelenchoides Besseyi Isolates and Their Expression Correlation to the Fenamiphos Treatment

Author(s):  
Jung-Kai Hsu ◽  
Chia-Wei Weng ◽  
Jeremy J.W. Chen ◽  
Peichen J. Chen

Abstract Aphelenchoides besseyi could cause great yield loss on rice and many economically important crops. Acetylcholinesterase inhibitors were commonly used to mitigate plant parasitic nematodes. However, increasing nematicide-resistance has been reported due to the extensive use of these chemicals. The correlation between the AChE-inhibitor (fenamiphos) sensitivities and acetylcholinesterase (ace) genes in two isolates of A. besseyi (designated Rl and HSF) was established. The LD50 of fenamiphos to Rl and HSF were 572.2 ppm and 129.4 ppm, respectively, indicating that two nematode isolates had different sensitivities to fenamiphos. Three ace genes were cloned and sequenced in A. besseyi, and their homology was supported by phylogenic analysis with AChEs protein sequences from various vertebrate and invertebrate species. Molecular docking showed that the affinities of each AChEs to fenamiphos were higher in HSF isolate, indicating that there should be point mutations in Rl isolate AChEs. Treating the two isolates with 100 ppm fenamiphos for 12 h, three ace genes of HSF isolate were down-regulated but were up-regulated in Rl isolate. The results suggest that fenamiphos can transcriptionally modulate the expression of ace genes, as well as the variants in AChEs and increased expression of ace genes might be associated with fenamiphos-insensitivity in Rl isolate.

EDIS ◽  
2020 ◽  
Vol 2020 (3) ◽  
Author(s):  
Lindsay Wheeler ◽  
William Talmadge Crow

There are nematodes of several genera that feed on plant stems and foliage, including Aphelenchoides, Bursaphelenchus, Anguina, Ditylenchus and Litylenchus. Herein, we apply the common name “foliar nematode” specifically to plant-feeding nematodes in the genus Aphelechoides, specifically Aphelenchoides besseyi, Aphelenchoides fragariae, and Aphelenchoides ritzemabosi. While most members of Aphelenchoides are fungivorous (feed on fungi), these three species have populations that are facultative plant-parasites that can feed on live plant tissue. Ten other species of Aphelenchoides also are recognized as facultative plant-parasites, but these are not as commonly encountered or as economically significant as the aforementioned species. Unlike most plant-parasitic nematodes, foliar nematodes can infest the aerial portions of plants rather than dwelling strictly in soil and plant roots. Damage from their feeding can reduce yield in food crops and ruin the appearance of ornamentals.https://edis.ifas.ufl.edu/in1279


2014 ◽  
Vol 15 (3) ◽  
pp. 112-117 ◽  
Author(s):  
T. C. Todd ◽  
J. A. Appel ◽  
J. Vogel ◽  
N. A. Tisserat

Observations on the prevalence and abundance of plant-parasitic nematodes were made from soil and root samples collected from 2,640 wheat fields in Kansas and Colorado during 2007-2010. Stunt nematodes (predominately Merlinius brevidens and Quinisulcius acutus), root-lesion nematodes (predominately Pratylenchus neglectus), and pin nematodes (Paratylenchus projectus) were the most commonly encountered taxa. Maximum soil population densities of 6,520 and 1,880 nematodes/100 cm3 soil were observed for pin and stunt nematodes, respectively, while a maximum root population density of 90,309 nematodes/g dry root was observed for root-lesion nematodes. Lower nematode densities were associated with wheat following corn, grain sorghum, or soybean for pin and stunt nematodes, and with wheat following fallow for root-lesion nematodes. Based on the results of this survey, 6% and 8% of wheat acreage in the central Great Plains are estimated to be at risk for significant (>5%) yield loss due to stunt nematodes and root-lesion nematodes, respectively. The number of fields with high population densities of both stunt and root-lesion nematodes was negligible (1%); therefore, the total wheat acreage with nematode populations above provisional economic thresholds is estimated to be ∼13%. Damage relationships with greater accuracy, precision, and relevance are necessary to establish reliable yield loss estimates for this region. 3 June 2014. 11 August 2014.


Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 374
Author(s):  
Hui Feng ◽  
Dongmei Zhou ◽  
Paul Daly ◽  
Xiaoyu Wang ◽  
Lihui Wei

The glycoside hydrolase family 16 (GH16) is widely found in prokaryotes and eukaryotes, and hydrolyzes the β-1,3(4)-linkages in polysaccharides. Notably, the rice white tip nematode Aphelenchoides besseyi harbors a higher number of GH16s compared with other plant-parasitic nematodes. In this work, two GH16 genes, namely AbGH16-1 and AbGH16-2, were isolated and characterized from A. besseyi. The deduced amino acid sequences of AbGH16-1 and AbGH16-2 contained an N-terminal signal peptide and a fungal Lam16A glucanase domain. Phylogenetic analysis revealed that AbGH16-1 and AbGH16-2 clustered with ascomycete GH16s, suggesting AbGH16-1 and AbGH16-2 were acquired by horizontal gene transfer from fungi. In situ hybridization showed that both AbGH16-1 and AbGH16-2 were specifically expressed in the nematode gonads, correlating with qPCR analysis that showed the high transcript levels of the two genes in the female nematodes. AbGH16-1 and AbGH16-2 were also significantly induced in nematodes feeding on Botrytis cinerea. Characterization of the recombinant protein showed AbGH16-1 and AbGH16-2 displayed pronounced inhibition of both conidial germination and germ tube elongation of B. cinerea. In addition, silencing of AbGH16-1 and AbGH16-2 by RNA interference significantly decreased the reproduction ability of A. besseyi and had a profound impact on the development process of offspring in this nematode. These findings have firstly proved that GH16s may play important roles in A.besseyi feeding and reproduction on fungi, which thus provides novel insights into the function of GH16s in plant-parasitic nematodes.


2020 ◽  
Vol 4 (3) ◽  
pp. 496-504
Author(s):  
Julius Bulus ◽  
Peter Abraham ◽  
Mercy Joshua ◽  
Dauda Elisha Shamaki ◽  
Christopher Tobe Okolo ◽  
...  

Ginger (Zingiber officinale) is an important cash crop in Nigeria. In spite of the economic importance of plant-parasitic nematodes reported on ginger, little or no information is available as regards plant-parasitic nematodes diversity and abundance on ginger in Nigeria. This work was conducted in 2018 to identify plant-parasitic nematodes associated with ginger in Kaduna state and to determine their population densities. Three Local Government Areas (LGA) were visited and between 12 to 16 ginger farms were sampled per LGA. A total of 42 soil samples was collected at a depth of 0 - 30 cm of the plant rhizosphere. Plant-parasitic nematodes were extracted from the soil using modified sieving and decanting method. Identification to genera level was done using identification keys viewing with dissecting microscope at X40 magnification. Nineteen (19) genera of plant-parasitic nematodes were identified, with 12 genera occurring in all LGA(s). Scutellonema (113.33), Meloidogyne (110), and Pratylenchus (93.33) were the most abundant per 100 ml of soil when locations are combined. Plant-parasitic nematodes population average was 870-950 per 100 ml of soil. All locations showed a high percentage similarity of plant-parasitic nematodes diversity and were statistically similar. This high diversity and population abundance can be among the reasons for the low productivity of ginger in Nigeria. It is therefore important to educate farmers on the economic importance of plant-parasitic nematodes on ginger and its management. Further research using the most occurring genera to establish the threshold population densities capable of causing economic yield loss needs to be conducted


EDIS ◽  
2021 ◽  
Vol 2021 (1) ◽  
pp. 13
Author(s):  
Z. J. Grabau ◽  
J. W. Noling

Many different plant-parasitic nematodes cause yield loss in cabbage, broccoli, collards, and other valuable Florida cole crops. This 13-page fact sheet written by Z. J. Grabau and J. W. Noling and published by the UF/IFAS Entomology and Nematology Department lists common symptoms, explains how to submit samples to a nematology lab such as the UF/IFAS Nematode Assay Lab for diagnosis, and describes key cultural practices to help agricultural professionals spot and manage nematode problems in cole crops.


Nematology ◽  
2017 ◽  
Vol 19 (2) ◽  
pp. 237-244 ◽  
Author(s):  
Daisuke Ito ◽  
Koki Toyota ◽  
Zhen Guang Li

Yellowing symptoms sometimes cause yield losses in green soybean cultivation. The objective of this study was to estimate the yield loss factors in a glasshouse. The parameters evaluated were plant-parasitic nematodes (Heterodera glycines, Pratylenchus penetrans, Meloidogyne spp.) and soil chemical properties. While the density of H. glycines did not show a negative correlation with yield in the February planting date, it showed a strongly negative correlation in the March planting date. Multiple regression analysis showed that yield was significantly correlated with P. penetrans and nitrate in the February planting, and with H. glycines and K in the March planting. The present study revealed that yield loss was caused by P. penetrans and nitrate in seasons with unsuitable temperatures for H. glycines hatch, and by H. glycines and alleviated by K in seasons with optimum temperatures for H. glycines hatching.


1987 ◽  
Vol 14 (2) ◽  
pp. 94-96 ◽  
Author(s):  
T. A. Wheeler ◽  
J. L. Starr

Abstract The distribution of plant-parasitic nematodes in five Texas peanut producing counties was determined during 1985 and 1986 growing seasons. Criconemella, the most frequently detected genus, was present in 83.4% of the samples; evidence of crop damage was not observed. Meloidogyne arenaria was detected in 15.5% of the samples. In microplot tests, there was a significant negative relationship between initial populations of M. arenaria and peanut yields; a linear model estimates a 10% yield loss with initial populations of 44–83 M. arenaria/500 cm3 soil. At least 10% of the survey samples were estimated to have root-knot nematode populations exceeding that necessary for a 10% yield loss. Other parasitic genera found in the survey were Pratylenchus (15.7% of the samples) and Belonolaimus (0.8% of the samples). While pod symptoms of Pratylenchus damage were observed, reliable yield loss estimates can not be made with existing data.


2017 ◽  
Vol 62 (3) ◽  
Author(s):  
Bu-Yong Wang ◽  
Rong-Rong Wen ◽  
Ling Ma

Abstract, the nematode agent of rice tip white disease, causes huge economic losses in almost all the rice-growing regions of the world. Glutathione peroxidase (GPx), an esophageal glands secretion protein, plays important roles in the parasitism, immune evasion, reproduction and pathogenesis of many plant-parasitic nematodes (PPNs). Therefore, GPx is a promising target for control


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