Effect of Fusarium oxysporum endophyte inoculation on the activities of phenylpropanoid pathway enzymes and Radopholus similis numbers in susceptible and tolerant East African Highland bananas

Nematology ◽  
2010 ◽  
Vol 12 (3) ◽  
pp. 469-480 ◽  
Author(s):  
Daniel Coyne ◽  
Thomas Dubois ◽  
Pamela Paparu ◽  
Altus Viljoen
Keyword(s):  
Wound Healing ◽  
Fusarium Oxysporum ◽  
Plant Defence ◽  
Constitutive Expression ◽  
Phenylpropanoid Pathway ◽  
Radopholus Similis ◽  
East African ◽  
Antagonistic Effects ◽  
Pal Activity ◽  
Burrowing Nematode

AbstractPhenylpropanoid pathway enzymes are involved in plant defence pathways leading to lignification, synthesis of secondary metabolites, such as salicylic acid and phytoalexins, wound healing and the oxidative burst. Endophytic non-pathogenic Fusarium oxysporum isolate V5w2 has been reported to show antagonistic effects against Radopholus similis in the screenhouse. An experiment was designed to study root biochemical changes (PAL, POX and PPO activities) and R. similis numbers in susceptible and tolerant bananas following inoculation with isolate V5w2. Constitutive expression of PAL and PPO were similar between the susceptible and tolerant cultivars, while constitutive POX activity was higher in the tolerant cultivar. PAL activity was suppressed in both cultivars 7 days after endophyte inoculation (7 dai), but was significantly up-regulated in the susceptible cv. Nabusa at 30 days post nematode challenge (dpnc) in endophyte-inoculated plants. In the tolerant cultivar, PAL activity was up-regulated in R. similis-challenged plants at 7 and 30 dpnc, irrespective of endophyte inoculation. POX and PPO were transiently up-regulated in cv. Nabusa 7 dai, exceeding levels observed in non-inoculated plants of the same cultivar. POX activity was up-regulated at 7 dpnc in endophyte-inoculated cv. Nabusa plants challenged with R. similis. In the tolerant cultivar, POX and PPO activities were similarly up-regulated in R. similis-challenged plants at 7 dpnc, irrespective of endophyte inoculation. The findings of this study implicate PAL, POX and PPO in banana defence against the root-burrowing nematode R. similis. Our findings further demonstrate the ability of endophytic F. oxysporum isolate V5w2 directly to induce POX and prime PAL in the susceptible cv. Nabusa for greater up-regulation following R. similis challenge.

Activity of phenylalanine ammonia-lyase, peroxidase and polyphenol oxidase in roots of banana (Musa acuminata AAA, cvs Grande Naine and Yangambi km5) before and after infection with Radopholus similis

Nematology ◽  
2006 ◽  
Vol 8 (2) ◽  
pp. 201-209 ◽  
Author(s):  
Nathalie Wuyts ◽  
Rony Swennen ◽  
Dirk De Waele
Keyword(s):  
Polyphenol Oxidase ◽  
Phenylalanine Ammonia Lyase ◽  
Phenylpropanoid Pathway ◽  
Musa Acuminata ◽  
Resistant Cultivar ◽  
Radopholus Similis ◽  
Wound Induction ◽  
Pal Activity ◽  
Before And After ◽  
Burrowing Nematode

AbstractPhenylpropanoids – phenolic compounds – take part in the wound and defence responses of plants and are frequently correlated with resistance. Enzymes directly or indirectly functional in the phenylpropanoid pathway are induced in plants in response to wounding and infection by pathogens, including sedentary endoparasitic nematodes. The activity of three of these enzymes, phenylalanine ammonia-lyase (PAL), peroxidase (PO) and polyphenol oxidase (PPO), was analysed in banana roots before and 1, 3 and 7 days after inoculation with the burrowing nematode Radopholus similis and in comparison with mechanically wounded roots. Constitutive activities of PAL, PO and PPO were lower in the resistant cv. Yangambi km5 (Musa acuminata AAA) than in the susceptible cv. Grande Naine (Musa acuminata AAA). During the experiment, levels increased to those of cv. Grande Naine, but only for R. similis-inoculated roots of cv. Yangambi km5 enzyme activities at 3 and 7 days after the onset of the experiment were values significantly higher than constitutive ones. At 7 days after the treatments, PO activity was significantly higher in wounded roots of cv. Grande Naine than in control and nematode-inoculated roots. The level of PAL activity in nematode-treated roots of cv. Yangambi km5 at 7 days after inoculation was 2.3-fold higher than control and wounded roots and up to six-fold higher than cv. Grande Naine roots. We concluded that PAL was induced in R. similis-inoculated roots of the resistant cultivar only and that this response was different from wound induction. For PO and PPO we concluded that levels in the resistant cultivar increased to those of the susceptible cultivar as a response to general stress in the plants during the experiment. Nevertheless, final levels of PO and PPO activity in R. similis-inoculated roots of the resistant cultivar were significantly higher than constitutive ones.

Phenols and lignin are involved in the defence response of banana (Musa) plants to Radopholus similis infection

Nematology ◽  
2014 ◽  
Vol 16 (5) ◽  
pp. 565-576 ◽  
Author(s):  
Suganthagunthalam Dhakshinamoorthy ◽  
Kahpui Mariama ◽  
Annemie Elsen ◽  
Dirk De Waele
Keyword(s):  
Cross Sections ◽  
Plant Defence ◽  
Defence Response ◽  
Nematode Infection ◽  
Vascular Bundles ◽  
Radopholus Similis ◽  
Phenol Content ◽  
Root Cortex ◽  
Root Cells ◽  
Burrowing Nematode

The role of lignin and phenols in plant defence ranges from preformed characteristic to inducible physical and chemical response against nematode infection. Our study shows the involvement of lignin and phenols in the defence of two newly identified resistant banana (Musa) genotypes to burrowing nematode Radopholus similis infection. Results were compared with reference resistant and susceptible banana cultivars. Histochemical analysis of root cross sections showed a more extensive secondary cell wall lignification of vascular bundles in R. similis-infected plants than in the nematode non-infected plants. Increased extensive lignification was not associated with the cortex cells that are directly attacked by the nematode. This showed that the increased lignification is a general defence response to protect the vascular bundle from damage rather than resisting the nematode development and reproduction at the root cortex. Histochemical localisation showed no preformed phenolic cells in the cortex of the non-infected, R. similis-resistant and -susceptible Musa genotypes. By contrast, phenolic substances were the major constituents of the nematode-infected necrotic cells. Phenols and lignin contents were also quantitatively assayed. The Folin-Ciocalteu assay confirmed the increase in phenol content of nematode-infected root cells. Phenol content in nematode-infected plants was twice the amount of phenol content in nematode non-infected plants at 3 weeks after infection. This is possibly due to the biosynthesis or accumulation of secondary metabolites such as phenolic phytoalexins in the nematode infection sites of all the banana genotypes. This study clearly demonstrates that phenols and lignin play an important role in the defence mechanisms of Musa to R. similis infection.

In vitro antagonism of endophytic Fusarium oxysporum isolates against the burrowing nematode Radopholus similis

Nematology ◽  
2006 ◽  
Vol 8 (4) ◽  
pp. 627-636 ◽  
Author(s):  
Bjoern Niere ◽  
Shahasi Athman ◽  
Altus Viljoen ◽  
Clifford Gold ◽  
Thomas Dubois ◽  
...  
Keyword(s):  
Fusarium Oxysporum ◽  
Mortality Rates ◽  
Antagonistic Activity ◽  
Radopholus Similis ◽  
Biological Control Agents ◽  
Inhibitory Effects ◽  
Culture Filtrates ◽  
Burrowing Nematode ◽  
Nematode Mortality

AbstractRadopholus similis is one of the key pests of banana worldwide. In this study, nine endophytic Fusarium oxysporum isolates were screened for the production of secondary metabolites antagonistic to R. similis in culture. Undiluted and diluted culture filtrates were tested against motile stages and eggs of R. similis. All isolates tested demonstrated in vitro antagonistic activity, causing paralysis of R. similis motile stages. The percentage of paralysed nematodes increased with increase in the length of exposure time to culture filtrates. After 24 h exposure in culture filtrates up to 100% of the treated nematodes were paralysed compared to 26.5% in the control treatments. Nematode mortality rates after 24 h exposure in culture filtrates ranged from 76.4% to 100%. Paralysis was reversible at lower filtrate concentrations. Radopholus similis males were more sensitive to culture filtrates than females. Culture filtrates of all isolates demonstrated inhibitory effects on hatching of R. similis eggs. The results demonstrate the potential for using endophytic F. oxysporum as biological control agents against R. similis and for toxic derivatives from their secondary metabolism to be used as potential nematicides.

Effect of endophytic Fusarium oxysporum on root penetration and reproduction of Radopholus similis in tissue culture-derived banana (Musa spp.) plants

Nematology ◽  
2007 ◽  
Vol 9 (5) ◽  
pp. 599-607 ◽  
Author(s):  
Altus Viljoen ◽  
Nico Labuschagne ◽  
Thomas Dubois ◽  
Shahasi Athman ◽  
Daniel Coyne ◽  
...  
Keyword(s):  
Tissue Culture ◽  
Fusarium Oxysporum ◽  
Root Penetration ◽  
Host Searching ◽  
Radopholus Similis ◽  
Biological Control Agents ◽  
Nematode Reproduction ◽  
Musa Spp ◽  
Plant Infection ◽  
Burrowing Nematode

AbstractIn Uganda, banana (Musa spp.) production is constrained by the burrowing nematode Radopholus similis. Non-pathogenic, endophytic Fusarium oxysporum has been isolated from healthy banana plants, and several strains have shown potential as biological control agents against R. similis. Plant infection by R. similis can be characterised in three steps: host searching, root penetration and reproduction. In this study, we investigated the effects of three endophytic F. oxysporum strains (Eny1.31i, Eny7.11o and V5w2) on root penetration and reproduction of R. similis in tissue culture-derived banana plants. The number of R. similis that penetrated roots of endophyte-inoculated and untreated plants was not influenced by the endophytes in either laboratory or screenhouse experiments. However, R. similis reproduction was reduced by endophytes. Strain V5w2 gave the greatest suppression of R. similis reproduction. The results of this study imply that antagonism of endophytic F. oxysporum against R. similis in banana plants is post-infectional and mediated through disruption of nematode reproduction.

Fusarium oxysporum endophytes induced systemic resistance against Radopholus similis on banana

Nematology ◽  
2006 ◽  
Vol 8 (6) ◽  
pp. 847-852 ◽  
Author(s):  
Tam Vu ◽  
Richard Sikora ◽  
Rüdiger Hauschild
Keyword(s):  
Fusarium Oxysporum ◽  
Root System ◽  
Endophytic Fungi ◽  
Fungal Endophyte ◽  
Systemic Resistance ◽  
Root Penetration ◽  
Radopholus Similis ◽  
Split Root ◽  
Split Root System ◽  
Burrowing Nematode

AbstractFour mutualistic endophytic fungal isolates were investigated for their ability to induce systemic resistance in banana toward the burrowing nematode, Radopholus similis in glasshouse experiments. Two isolates of Fusarium oxysporum and one of F. cf. diversisporum isolated from the cortical tissue of banana, and another isolate of F. oxysporum isolated from tomato, were compared. When the root systems of seedling banana plants were pre-inoculated with the four endophytic fungi, R. similis root penetration was reduced by 29-39% and 22-41% 5 and 15 days after nematode inoculation, respectively. Induction of systemic resistance to R. similis in banana roots by the same endophytic fungi was tested in a split-root system. Depending on the isolate, the penetration rates decreased between 30-38.5% and 26.7-45% after 5 and 15 days in the untreated half of the split-root system of plants treated with the endophytic strains when compared to those treated without the fungi. This is the first time that systemic resistance induced by a fungal endophyte has been demonstrated in banana.

scholarly journals Interaction between Fusarium oxysporum f. sp. cubense and Radopholus similis can lead to changes in the resistance of banana cultivars to Fusarium wilt

2020 ◽  
Author(s):  
Anelita de Jesus Rocha ◽  
Mileide dos Santos Ferreira ◽  
Leandro de Souza Rocha ◽  
Saulo A. S. Oliveira ◽  
Edson Perito Amorim ◽  
...  
Keyword(s):  
Fusarium Oxysporum ◽  
Fusarium Wilt ◽  
Durable Resistance ◽  
Resistance Pattern ◽  
Radopholus Similis ◽  
Breeding Programs ◽  
Panama Disease ◽  
Burrowing Nematode ◽  
Race 1

Abstract Fusarium oxysporum f. sp. cubense (Foc) causes Panama disease or Fusarium wilt of bananas. The association between soil-inhabiting fungi and nematodes can increase the severity of symptoms and suppress the resistance of plants to diseases. In this study, the interaction between Foc race 1 and Radopholus similis, a burrowing nematode that parasitizes banana plants, was analyzed using one moderately susceptible cultivar and seven resistant cultivars of banana. Two Foc isolates that differed in virulence were tested. The analyses of symptoms and stained fungal structures in the roots demonstrated that R. similis interacting with Foc in different inoculation sequences caused changes in symptom severity and the resistance pattern to Foc isolate 0801 (race 1) in cultivars ‘Terra Maranhão’, ‘BRS Pacovan Ken’, ‘BRS Vitória’, and ‘BRS Platina’. The data generated in this study have relevant implications for banana breeding programs in the classification of cultivars for durable resistance to Fusarium wilt and for understanding pathogen interactions during occurrence of the disease.

Response of East African highland bananas and hybrids to Radopholus similis

Nematology ◽  
2005 ◽  
Vol 7 (5) ◽  
pp. 655-666 ◽  
Author(s):  
Abdou Tenkouano ◽  
Dirk De Waele ◽  
Rodomiro Ortiz ◽  
Jim Whyte ◽  
Carine Dochez
Keyword(s):  
Host Response ◽  
Nematode Population ◽  
Host Responses ◽  
Radopholus Similis ◽  
East African ◽  
Male And Female ◽  
Banana Production ◽  
Burrowing Nematode ◽  
The Individual ◽  
Individual Root

AbstractThe burrowing nematode, Radopholus similis, is a serious threat to sustainable banana production worldwide. A promising way of controlling nematodes is through the development and deployment of resistant cultivars. This usually involves crossing triploid cultivars with fertile diploids to produce tetraploids that generally display greater male and female fertility. Selected tetraploids are then crossed with improved diploids to produce sterile secondary triploids. This study evaluates the host response of the most commonly grown East African highland bananas in Uganda. Also, the host responses of diploid hybrids and East African highland banana derived hybrids, including tetraploids and secondary triploids, were evaluated. The individual root inoculation method was used for screening the Musa accessions for resistance to R. similis. The final nematode population of each accession was compared with the final nematode population of a susceptible reference cultivar, Valery, and with the final nematode population of a resistant reference cultivar, Yangambi km5. Results show that, except for cv. Muvubo, East African highland bananas were as susceptible to R. similis as cv. Valery. Four out of 13 tetraploid hybrids were identified with resistance to R. similis, as well as 13 out of 19 diploids and five out of 18 secondary triploids.

Attraction and penetration of Musa by the burrowing nematode, Radopholus similis, in an autotrophic bipartite culture system

Nematology ◽  
2021 ◽  
pp. 1-14
Author(s):  
Suganthagunthalam Dhakshinamoorthy ◽  
Erwin J. Galon ◽  
Annemie Elsen ◽  
Dirk De Waele
Keyword(s):  
Culture System ◽  
Model System ◽  
Radopholus Similis ◽  
Susceptible Plant ◽  
Compartment System ◽  
Female Migration ◽  
Equal Distance ◽  
Burrowing Nematode ◽  
Nematode Chemotaxis

Summary Our objective was to discover the stages (pre- or post-infection) in which the resistance to burrowing nematode (Radopholus similis) occurs in two resistant banana (Musa spp.) cultivars. An autotrophic in vitro culture system was used to compare R. similis migration towards, and penetration into, the banana roots. A new two-compartment autotrophic in vitro model system was developed using agar-based medium to examine the migration of R. similis to either the susceptible ‘Grande Naine’ or the resistant ‘Yangambi km5’ (‘Ykm5’), when both the Musa genotypes were present at equal distance. The autotrophic in vitro model system was advantageous, because it supported continuous root growth due to the actively photosynthesising shoots growing in the open air, while the in vitro root conditions make it possible to observe and assess the nematode chemotaxis in the transparent medium. Significantly fewer nematodes migrated towards the resistant ‘Ykm5’ plants when compared to both the susceptible ‘Grande Naine’, and another resistant cultivar, ‘Saba’, at 1 h after infection. This signals a possibility of a lower concentration or different composition of nematode attractants in ‘Ykm5’ root exudates. No significant differences were observed in the percentage of R. similis that migrated towards the roots of the susceptible and resistant banana plants at 3, 4 and 6 h after inoculation. No significant differences were observed in the percentages of female penetration in the resistant and susceptible plant roots at 1 and 2 days after inoculation. The results of the two-compartment system confirmed that when a choice is given to migrate towards the resistant and susceptible genotypes, no differences were observed in the percentage of female migration towards both the genotypes.

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