scholarly journals A Wild Cajanus scarabaeoides (L.), Thouars, IBS 3471, for Improved Insect-Resistance in Cultivated Pigeonpea

Agronomy ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 517
Author(s):  
Abigail Ngugi-Dawit ◽  
Thi My Linh Hoang ◽  
Brett Williams ◽  
Thomas J.V. Higgins ◽  
Sagadevan G. Mundree
Keyword(s):  
Insect Resistance ◽  
Cysteine Proteinase ◽  
Resistance Mechanism ◽  
Resistance Mechanisms ◽  
Economic Losses ◽  
Cysteine Proteinase Inhibitor ◽  
Potential Candidate ◽  
Interspecific Hybridisation ◽  
Leaf Powder ◽  
Wild Pigeonpea

Cajanus scarabaeoides (L.), Thouars, is the closest wild crop relative of cultivated pigeonpea, Cajanus cajan (L.), Millspaugh. This wild pigeonpea has several insect-resistance mechanisms, particularly to Helicoverpa armigera (Hübner). Estimated economic losses in the semi-arid tropics from H. armigera damage in pigeonpea are approximately two billion USD/year. Therefore, it is imperative to improve pest resistance in this crop. In this study, we investigated insect-resistance components in IBS 3471, a C. scarabaeoides accession, and explored the possibility of transferring resistance mechanism/s to cultivated pigeonpea. A detached leaf bioassay revealed that IBS 3471 has more effective antibiosis and antixenosis resistance mechanisms against H. armigera compared to the susceptible C. cajan variety, ICPL 87. To further investigate the antibiosis resistance mechanism, we fed H. armigera larvae a heated and non-heated artificial diet supplemented with lyophilised IBS 3471 leaf powder. Incorporation of IBS 3471 leaf powder inhibited H. armigera larval weight and delayed larval development compared to larvae reared on diet supplemented with ICPL 87 leaf powder. The putative insect-resistance compounds in C. scarabaeoides were heat-labile. Proteomic analysis revealed higher levels of potential insecticidal proteins, namely lectin and cysteine proteinase inhibitor, in wild pigeonpea compared to the cultivated variety. Nutritional analysis and interspecific hybridisation experiments also indicated that IBS 3471 is a potential candidate for improvement of insect-resistance in pigeonpea. This study demonstrates that IBS 3471 has multiple resistance mechanisms against H. armigera, and they are transferable to cultivated pigeonpea.

scholarly journals Investigation of Insect Resistance Components in Wild Pigeonpea Cajanus Scarabaeoides

Proceedings ◽  
2019 ◽  
Vol 36 (1) ◽  
pp. 27
Author(s):  
Hoang ◽  
Dawit ◽  
Williams ◽  
Higgins ◽  
Mundree
Keyword(s):  
Insect Resistance ◽  
Larval Mortality ◽  
Resistance Mechanism ◽  
Resistance Mechanisms ◽  
Economic Losses ◽  
Resistance Components ◽  
Leaf Powder ◽  
Antibiosis Resistance ◽  
Neonate Larvae ◽  
Wild Pigeonpea

Cajanus scarabaeoides (L.) Thouars is the closest wild relative of cultivated pigeonpea, Cajanus cajan (L.) Millspaugh. However, unlike cultivated pigeonpea which is very susceptible to insects, especially Helicoverpa armigera (Hubner), this wild pigeonpea is strongly insect resistant. Since H. armigera causes damage to many important crops resulting in economic losses up to 2 billion USD/year, improvement in resistance to this insect in crops is highly desirable. Here we investigate insect resistance components in C. scarabaeoides and explore the possibility of transferring one or more of those factors to cultivated pigeonpea. A detached leaf assay was used to assess antibiosis and antixenosis resistance mechanisms in C. scarabaeoides. Artificial diet supplemented with lyophilised leaf powder was employed to investigate the antibiosis resistance mechanism. Data on larval mortality and larval and pupal weights were collected. Time taken for neonate larvae to pupate and for pupae to develop to the moth stage were determined through daily observations. Preliminary results showed that H. armigera larval weight was significantly reduced and larval development stages were prolonged when reared on different accessions of C. scarabaeoides as compared to the susceptible check, C. cajan (ICPL 87). Interspecific hybridization was carried out between C. scarabaeoides and a commercial pigeonpea variety. Results from insect challenge assays and trichome identification indicate that the hybrids have similar levels of insect resistance to their wild parent. Proteomic analysis is being used to identify possible antibiosis factors.

scholarly journals Integration of early disease-resistance phenotyping, histological characterization, and transcriptome sequencing reveals insights into downy mildew resistance in impatiens

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Ze Peng ◽  
Yanhong He ◽  
Saroj Parajuli ◽  
Qian You ◽  
Weining Wang ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Downy Mildew ◽  
Transcriptome Sequencing ◽  
Early Stage ◽  
Economic Losses ◽  
Potential Candidate ◽  
Early Disease ◽  
True Leaf ◽  
Cotyledon Stage ◽  
Wide Range

AbstractDowny mildew (DM), caused by obligate parasitic oomycetes, is a destructive disease for a wide range of crops worldwide. Recent outbreaks of impatiens downy mildew (IDM) in many countries have caused huge economic losses. A system to reveal plant–pathogen interactions in the early stage of infection and quickly assess resistance/susceptibility of plants to DM is desired. In this study, we established an early and rapid system to achieve these goals using impatiens as a model. Thirty-two cultivars of Impatiens walleriana and I. hawkeri were evaluated for their responses to IDM at cotyledon, first/second pair of true leaf, and mature plant stages. All I. walleriana cultivars were highly susceptible to IDM. While all I. hawkeri cultivars were resistant to IDM starting at the first true leaf stage, many (14/16) were susceptible to IDM at the cotyledon stage. Two cultivars showed resistance even at the cotyledon stage. Histological characterization showed that the resistance mechanism of the I. hawkeri cultivars resembles that in grapevine and type II resistance in sunflower. By integrating full-length transcriptome sequencing (Iso-Seq) and RNA-Seq, we constructed the first reference transcriptome for Impatiens comprised of 48,758 sequences with an N50 length of 2060 bp. Comparative transcriptome and qRT-PCR analyses revealed strong candidate genes for IDM resistance, including three resistance genes orthologous to the sunflower gene RGC203, a potential candidate associated with DM resistance. Our approach of integrating early disease-resistance phenotyping, histological characterization, and transcriptome analysis lay a solid foundation to improve DM resistance in impatiens and may provide a model for other crops.

scholarly journals A novel cysteine proteinase inhibitor from seeds of Enterolobium contortisiliquum and its effect on Callosobruchus maculatus larvae

2021 ◽  
Vol 25 ◽  
pp. 100876
Author(s):  
Natalia N.S. Nunes ◽  
Rodrigo S. Ferreira ◽  
Leonardo F.R. de Sá ◽  
Antônia Elenir A. de Oliveira ◽  
Maria Luiza V. Oliva
Keyword(s):  
Proteinase Inhibitor ◽  
Callosobruchus Maculatus ◽  
Cysteine Proteinase ◽  
Cysteine Proteinase Inhibitor

scholarly journals Characterization of resistance mechanisms of Enterobacter cloacae Complex co-resistant to carbapenem and colistin

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Shixing Liu ◽  
Renchi Fang ◽  
Ying Zhang ◽  
Lijiang Chen ◽  
Na Huang ◽  
...  
Keyword(s):  
Lipid A ◽  
Efflux Pump ◽  
Resistance Mechanism ◽  
Carbapenem Resistance ◽  
Enterobacter Cloacae ◽  
Resistance Mechanisms ◽  
Colistin Resistance ◽  
Carbapenem Resistant ◽  
Horizontal Spread

Abstract Background The emergence of carbapenem-resistant and colistin-resistant ECC pose a huge challenge to infection control. The purpose of this study was to clarify the mechanism of the carbapenems and colistin co-resistance in Enterobacter cloacae Complex (ECC) strains. Results This study showed that the mechanisms of carbapenem resistance in this study are: 1. Generating carbapenemase (7 of 19); 2. The production of AmpC or ESBLs combined with decreased expression of out membrane protein (12 of 19). hsp60 sequence analysis suggested 10 of 19 the strains belong to colistin hetero-resistant clusters and the mechanism of colistin resistance is increasing expression of acrA in the efflux pump AcrAB-TolC alone (18 of 19) or accompanied by a decrease of affinity between colistin and outer membrane caused by the modification of lipid A (14 of 19). Moreover, an ECC strain co-harboring plasmid-mediated mcr-4.3 and blaNDM-1 has been found. Conclusions This study suggested that there is no overlap between the resistance mechanism of co-resistant ECC strains to carbapenem and colistin. However, the emergence of strain co-harboring plasmid-mediated resistance genes indicated that ECC is a potential carrier for the horizontal spread of carbapenems and colistin resistance.

Purification and Structure of a Novel Cysteine Proteinase Inhibitor, Strepin P-1

1985 ◽  
Vol 49 (3) ◽  
pp. 799-805
Author(s):  
Kyoichi Ogura ◽  
Mitsuru Maeda ◽  
Masami Nagai ◽  
Takaharu Tanaka ◽  
Kyosuke Nomoto ◽  
...  
Keyword(s):  
Proteinase Inhibitor ◽  
Cysteine Proteinase ◽  
Cysteine Proteinase Inhibitor

scholarly journals Black Queen Evolution and Trophic Interactions Determine Plasmid Survival after the Disruption of the Conjugation Network

mSystems ◽  
2018 ◽  
Vol 3 (5) ◽  
Author(s):  
Johannes Cairns ◽  
Katariina Koskinen ◽  
Reetta Penttinen ◽  
Tommi Patinen ◽  
Anna Hartikainen ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Bacterial Communities ◽  
Resistance Mechanism ◽  
Real Life ◽  
Ecological Factors ◽  
Mobile Genetic Elements ◽  
Resistance Mechanisms ◽  
Antibiotics Resistance ◽  
Bacterial Populations ◽  
Genetic Elements

ABSTRACTMobile genetic elements such as conjugative plasmids are responsible for antibiotic resistance phenotypes in many bacterial pathogens. The ability to conjugate, the presence of antibiotics, and ecological interactions all have a notable role in the persistence of plasmids in bacterial populations. Here, we set out to investigate the contribution of these factors when the conjugation network was disturbed by a plasmid-dependent bacteriophage. Phage alone effectively caused the population to lose plasmids, thus rendering them susceptible to antibiotics. Leakiness of the antibiotic resistance mechanism allowing Black Queen evolution (i.e. a “race to the bottom”) was a more significant factor than the antibiotic concentration (lethal vs sublethal) in determining plasmid prevalence. Interestingly, plasmid loss was also prevented by protozoan predation. These results show that outcomes of attempts to resensitize bacterial communities by disrupting the conjugation network are highly dependent on ecological factors and resistance mechanisms.IMPORTANCEBacterial antibiotic resistance is often a part of mobile genetic elements that move from one bacterium to another. By interfering with the horizontal movement and the maintenance of these elements, it is possible to remove the resistance from the population. Here, we show that a so-called plasmid-dependent bacteriophage causes the initially resistant bacterial population to become susceptible to antibiotics. However, this effect is efficiently countered when the system also contains a predator that feeds on bacteria. Moreover, when the environment contains antibiotics, the survival of resistance is dependent on the resistance mechanism. When bacteria can help their contemporaries to degrade antibiotics, resistance is maintained by only a fraction of the community. On the other hand, when bacteria cannot help others, then all bacteria remain resistant. The concentration of the antibiotic played a less notable role than the antibiotic used. This report shows that the survival of antibiotic resistance in bacterial communities represents a complex process where many factors present in real-life systems define whether or not resistance is actually lost.

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