Screening and Testing the Effect of Biocontrol Agents (Bacillus sp.) and Fusarium oxysporum f. sp. ciceri strains (Wilt) on Plant Defense Enzymes in Chickpea

The influence exerted by the mycoparasite Pythium oligandrum in triggering plant defense reactions was investigated using an experimental system in which tomato plants were infected with the crown and root rot pathogen Fusarium oxysporum f. sp. radicis-lycopersici. To assess the antagonistic potential of P. oligandrum against F. oxysporum f. sp. radicis-lycopersici, the interaction between the two fungi was studied by scanning and transmission electron microscopy (SEM and TEM, respectively). SEM investigations of the interaction region between the fungi demonstrated that collapse and loss of turgor of F. oxysporum f. sp. radicis-lycopersici hyphae began soon after close contact was established with P. oligandrum. Ultrastructural observations confirmed that intimate contact between hyphae of P. oligandrum and cells of the pathogen resulted in a series of disturbances, including generalized disorganization of the host cytoplasm, retraction of the plasmalemma, and, finally, complete loss of the protoplasm. Cytochemical labeling of chitin with wheat germ agglutinin (WGA)/ovomucoid-gold complex showed that, except in the area of hyphal penetration, the chitin component of the host cell walls was structurally preserved at a time when the host cytoplasm had undergone complete disorganization. Interestingly, the same antagonistic process was observed in planta. The specific labeling patterns obtained with the exoglucanase-gold and WGA-ovomucoid-gold complexes confirmed that P. oligandrum successfully penetrated invading cells of the pathogen without causing substantial cell wall alterations, shown by the intense labeling of chitin. Cytological investigations of samples from P. oligandrum-inoculated tomato roots revealed that the fungus was able to colonize root tissues without inducing extensive cell damage. However, there was a novel finding concerning the structural alteration of the invading hyphae, evidenced by the frequent occurrence of empty fungal shells in root tissues. Pythium ingress in root tissues was associated with host metabolic changes, culminating in the elaboration of structural barriers at sites of potential fungal penetration. Striking differences in the extent of F. oxysporum f. sp. radicis-lycopersici colonization were observed between P. oligandrum-inoculated and control tomato plants. In control roots, the pathogen multiplied abundantly through much of the tissues, whereas in P. oligandrum-colonized roots pathogen growth was restricted to the outermost root tissues. This restricted pattern of pathogen colonization was accompanied by deposition of newly formed barriers beyond the infection sites. These host reactions appeared to be amplified compared to those seen in nonchallenged P. oligandrum-infected plants. Most hyphae of the pathogen that penetrated the epidermis exhibited considerable changes. Wall appositions contained large amounts of callose, in addition to be infiltrated with phenolic compounds. The labeling pattern obtained with gold-complexed laccase showed that phenolics were widely distributed in Fusarium-challenged P. oligandrum-inoculated tomato roots. Such compounds accumulated in the host cell walls and intercellular spaces. The wall-bound chitin component in Fusarium hyphae colonizing P. oligandrum-inoculated roots was preserved at a time when hyphae had undergone substantial degradation. These observations provide the first convincing evidence that P. oligandrum has the potential to induce plant defense reactions in addition to acting as a mycoparasite.

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Chickpea-Fusarium oxysporum interaction transcriptome reveals differential modulation of plant defense strategies

Scientific Reports ◽

10.1038/s41598-017-07114-x ◽

2017 ◽

Vol 7 (1) ◽

Cited By ~ 10

Author(s):

Medha L. Upasani ◽

Bhakti M. Limaye ◽

Gayatri S. Gurjar ◽

Sunitha M. Kasibhatla ◽

Rajendra R. Joshi ◽

...

Keyword(s):

Plant Defense ◽

Fusarium Oxysporum ◽

Differential Modulation ◽

Defense Strategies

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Bacillus spp.; perspectiva de su efecto biocontrolador mediante antibiosis en cultivos afectados por fitopatógenos

Nova ◽

10.22490/24629448.501 ◽

2011 ◽

Vol 9 (16) ◽

pp. 177 ◽

Cited By ~ 2

Author(s):

Cristian Layton ◽

Edna Maldonado ◽

Luisa Monroy ◽

Lucía Constanza Corrales Ramírez MSC ◽

Ligia Consuelo Sánchez Leal MSC

Keyword(s):

Bacillus Subtilis ◽

Fusarium Oxysporum ◽

Bacillus Sp ◽

Bacillus Brevis ◽

Iturin A ◽

Bacillus Spp

El presente estudio documental evalúa el efecto biocontrolador del género Bacillus sp contra hongos fitopatógenos de plantas, particularmente, a través de relaciones antagónicas inductoras de muerte celular en términos inminentemente naturales. Fusarium oxysporum se encuentra muy relacionado con casos de marchitez vascular y pudrición de raíz en variedad de plantas, obstrucción de los vasos que permiten la circulación vegetal hasta causar amarillamiento de las hojas por imposibilidad en el transporte de nutrientes, causal de grandes pérdidas económicas en el campo agrícola nacional. Se han establecido varios mecanismos para controlar este hongo micelial dentro de las que se encuentran el uso extensivo y variable de agroquímicos y pesticidas, práctica que por sus efectos nocivos con el medio ambiente se ha comenzado a reemplazar por empleo de especies del género Bacillus. La acción biocontroladora de este género bacteriano esta mediada por su perfil bioquímico ya que son productores de múltiples metabolitos biológicamente activos, en el caso de Bacillus subtilis de Iturin A y fengycin y en Bacillus brevis de gramicidina S (1-5) son capaces de inhibir el desarrollo y crecimiento normal de otros microorganismos, lo que sugiere su utilización para el biocontrol de plagas en aras al fortalecimiento de los actuales estándares de calidad en los procesos ambientales.

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Jasmonic acid and nitric oxide protects naranjilla (Solanum quitoense) against infection by Fusarium oxysporum f. sp. quitoense by eliciting plant defense responses

Physiological and Molecular Plant Pathology ◽

10.1016/j.pmpp.2019.01.002 ◽

2019 ◽

Vol 106 ◽

pp. 129-136 ◽

Cited By ~ 1

Author(s):

Ana Cristina Ávila ◽

José Ochoa ◽

Karina Proaño ◽

M. Carmen Martínez

Keyword(s):

Nitric Oxide ◽

Jasmonic Acid ◽

Plant Defense ◽

Fusarium Oxysporum ◽

Defense Responses ◽

Plant Defense Responses

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Role of Biocontrol Agents in Management of Corm Rot of Saffron Caused by Fusarium oxysporum

Agronomy ◽

10.3390/agronomy10091398 ◽

2020 ◽

Vol 10 (9) ◽

pp. 1398

Author(s):

Vishal Gupta ◽

Krishna Kumar ◽

Kausar Fatima ◽

Vijay Kumar Razdan ◽

Bhagwati Charan Sharma ◽

...

Keyword(s):

Fusarium Oxysporum ◽

Growth Promotion ◽

Disease Incidence ◽

Biocontrol Agents ◽

Crocus Sativus ◽

First Year ◽

Dual Culture ◽

Maximum Reduction

Saffron (Crocus sativus L.) is considered as one of the most expensive spices. Fusarium corm rot of saffron, caused by Fusarium oxysporum, is known to cause severe yield losses worldwide. In the present study, efficacy of biocontrol agents (Trichoderma asperellum, Pseudomonas fluorescens, Pseudomonas aeruginosa, Pseudomonas putida, Bacillus stratosphericus, Bacillus pumilus, and Bacillus subtilis) along with a chemical fungicide, carbendazim, was evaluated for managing the corm rot of saffron. Under in vitro conditions, using dual culture and poison food techniques on potato dextrose agar, T. asperellum and carbendazim significantly reduced the mycelial growth of the pathogen F. oxysporum, with the inhibition of 62.76 and 60.27%, respectively, compared with control. Under field conditions, dipping of saffron corms in carbendazim and T. asperellum exhibited maximum reduction of 82.77 and 77.84%, respectively, in the disease incidence, during the first year of experiment. However, during the second year, maximum reduction in the incidence of corm rot (68.63%) was recorded with the T. asperellum. Moreover, the population density of F. oxysporum was also significantly reduced by 60 and 80.19% while using T. asperellum after 75 and 260 days of sowing of saffron corms, compared to its population before planting of corms. In case of growth promotion traits, such as sprouting and flowering, biocontrol treatments reduced the number of days (average) of sprouting and flower emergence after sowing, compared to control.

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