Establishment of an Artificial Inoculation Method of Ustilaginoidea virens without Damaging the Rice Panicle Sheaths

Rice false smut (RFS) is a destructive disease of rice worldwide caused by Ustilaginoidea virens. There is a lack of efficient and stable artificial inoculation method to simulate the natural infection of U. virens, which is an important factor limiting further research on the disease. The purpose of this study was to establish an artificial inoculation method, which can simulate the natural infection process of U. virens without destroying the panicle sheath structure of rice. In this research, rice plants were inoculated by soaking roots at the seedling stage, spraying at the tillering stage, injecting at the booting stage, and again spraying at the flowering stage to determine the appropriate artificial inoculation time. The panicle sheath instillation method and injection inoculation method were compared. The results show that stages 6 to 8 of young panicle differentiation are an important period for U. virens infection. There were no significant differences in the mean rates of infected panicles, mean rates of infected grains, and maximum infected grains per panicle between the two inoculation methods. However, the frequency of RFS ball occurrence at the upper part of the panicles was significantly higher on the spikelets inoculated by the injection method than that of spikelets inoculated by natural infection and panicle sheath instillation. Therefore, panicle sheath instillation method was more similar to the natural infection of U. virens in the field. This research exhibited an innovative artificial inoculation method for identification of U. virens pathogenicity and evaluation of rice resistance against RFS.

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Development of screening technique for artificial creation of false smut in rice

Journal of Applied and Natural Science ◽

10.31018/jans.v10i1.1613 ◽

2018 ◽

Vol 10 (1) ◽

pp. 253-257

Author(s):

Yesmin Kaur ◽

J. S. Lore ◽

P. P. S. Pannu

Keyword(s):

Susceptible Variety ◽

Potential Threat ◽

Spikelet Sterility ◽

Ustilaginoidea Virens ◽

Inoculation Method ◽

Inoculation Techniques ◽

Resistant Varieties ◽

Spray Inoculation ◽

Time Of Infection ◽

False Smut

False smut (Ustilaginoidea virens (Cooke) Takahashi) of rice is an emerging disease and a potential threat to rice growers in different countries due to reduction in yield, quality and production of mycotoxins. Development and cultivation of resistant varieties is desirable approach for its management. Different inoculation techniques viz. spray inoculation, syringe inoculation and dusting method were evaluated for creating artificial epiphytotic conditions in susceptible variety PR116 under natural as well as artificially provided humidity conditions. Spray inoculation method produced more number of smut balls per plant (3.21) and per cent infected panicles (33.44%) followed by syringe inoculation (2.00 and 26.57%, respectively) and dusting method (0.33 and 6.67%, respectively). However, syringe inoculation method produced more spikelet sterility (14.82%) in rice panicles. More disease occurrence was reported in plants provided with artificial humidity after inoculations (51.12% infected panicles) than the plants grown under natural conditions (13.33% infected panicles). Late transplanted crop developed higher disease severity (18.17% infected panicles and 3.34 smut balls/plant) which might be attributed by slight decrease in temperature and increase in relative humidity conditions (up to 88% RH) at time of infection from boot to early flowering stage of the rice crop.

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Advances in False Smut of Rice and its Integrated Diseases Management: A Review

Agricultural Reviews ◽

10.18805/ag.r-2131 ◽

2021 ◽

Author(s):

Munish Leharwan ◽

T.V. Arun Kumar

Keyword(s):

Rice Cultivation ◽

Integrated Disease Management ◽

Flowering Stage ◽

Resistance Development ◽

Abiotic And Biotic Stresses ◽

Ustilaginoidea Virens ◽

Tropical Regions ◽

Biotic Stresses ◽

False Smut ◽

Serious Disease

Rice is an important nutritive crop and primary staple food throughout the world. To reach the increasing global grain demand and food security, rice production needs to be monitored and increased. However, abiotic and biotic stresses have impeded rice cultivation both in tropical and sub-tropical regions. Among biotic stressors, false smut of rice incited by fungus Ustilaginoidea virens (Cooke, 1878) is one of the most common and serious disease throughout the rice cultivation areas and cause up to 40% loss in its yield. The disease is hard to stop, because fungus infect the crop during flowering stage and symptoms of the disease are evident after emergence of rice panicle. The fungus completely destroys the grains and converts them into spore balls, which are toxic and unfit for seed production. Further, control of false smut of rice through fungicide application is feasible; however, high usage of fungicides has led to the resistance development in causal agent besides environmental pollution. In this review, we update the most recent progress regarding the pathogen, its distribution, taxonomy, disease cycle and integrated disease management.

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Evaluation of Fungicides for the Control of Rice False Smut (Ustilaginoidea virens)

Bangladesh Rice Journal ◽

10.3329/brj.v20i2.34129 ◽

2017 ◽

Vol 20 (2) ◽

pp. 61-66

Author(s):

TH Ansari ◽

MT Khatun ◽

M Ahmed ◽

B Nessa ◽

MAI Khan ◽

...

Keyword(s):

Significant Variation ◽

Rice Variety ◽

Disease Suppression ◽

Flowering Stage ◽

Ustilaginoidea Virens ◽

Rice False Smut ◽

Fungicide Application ◽

False Smut ◽

And Control ◽

The Hill

Outbreak of false smut, caused by the fungus Ustilaginoidea virens has been recorded in recent years in the popular rice variety BRRI dhan49 from various parts of Bangladesh. Registered and/or recommended fungicides are not yet available for chemically controlling the disease. Consequently, uses of unregistered fungicides are common by the farmers for the management of the disease. The present study was, therefore, undertaken to identify effectiveness of any fungicides to control rice false smut disease. Seven synthetic foliar fungicides were evaluated in the naturally induced diseased plots. Each fungicide was applied as spray twice, at panicle initiation and at early flowering stage. Compared to the control (no fungicide application), the fungicide Controller 300 EC reduced the hill infection by 57%, followed by Green 300 EC, Cuprofix 30 Disperss and Diazole 300 EC, each of those suppressed the hill infection by 50%. While Cuprofix 30 Disperss, compared to the control, resulted in the lowest number of infected panicle per hill, it was statistically similar to rest of the fungicides except for Confidence 10 SL. Fungicides and control did not have any significant variation on the number of infected florets per panicle. With respect to per unit (hill infection × number of infected panicle per hill) disease suppression Controller 300 EC was the best. However, none of the fungicides reached the level of the disease suppression, the essential criterion for registration and/or recommendation of a fungicide under Bangladesh conditions. It is concluded that more multi-location and multi-season experiments will be required to reach a decisive conclusion on foliar chemical options for controlling rice false smut disease under Bangladesh conditions.Bangladesh Rice j. 2016, 20(2): 61-66

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Selection of cocoa clones for resistance to Phytophthora palmivora by artificial inoculation and natural infection in the field

Tropical Plant Pathology ◽

10.1007/s40858-021-00427-3 ◽

2021 ◽

Author(s):

Vanusa Rodrigues de Souza ◽

Edna Dora Martins Newman Luz ◽

José Luis Pires ◽

Marcos Vinicius Oliveira dos Santos ◽

Elisângela dos Santos ◽

...

Keyword(s):

Natural Infection ◽

Artificial Inoculation ◽

Phytophthora Palmivora ◽

Selection Of

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Nanoparticles as Adjuvants and Nanodelivery Systems for mRNA-Based Vaccines

Pharmaceutics ◽

10.3390/pharmaceutics13010045 ◽

2020 ◽

Vol 13 (1) ◽

pp. 45

Author(s):

Iman M. Alfagih ◽

Basmah Aldosari ◽

Bushra AlQuadeib ◽

Alanood Almurshedi ◽

Mariyam M. Alfagih

Keyword(s):

Messenger Rna ◽

Immune Cell ◽

Natural Infection ◽

Immunological Response ◽

Infection Process ◽

Dual Function ◽

Therapeutic Vaccines ◽

Non Invasive ◽

Recent Developments

Messenger RNA (mRNA)-based vaccines have shown promise against infectious diseases and several types of cancer in the last two decades. Their promise can be attributed to their safety profiles, high potency, and ability to be rapidly and affordably manufactured. Now, many RNA-based vaccines are being evaluated in clinical trials as prophylactic and therapeutic vaccines. However, until recently, their development has been limited by their instability and inefficient in vivo transfection. The nanodelivery system plays a dual function in RNA-based vaccination by acting as a carrier system and as an adjuvant. That is due to its similarity to microorganisms structurally and size-wise; the nanodelivery system can augment the response by the immune system via simulating the natural infection process. Nanodelivery systems allow non-invasive mucosal administration, targeted immune cell delivery, and controlled delivery, reducing the need for multiple administrations. They also allow co-encapsulating with immunostimulators to improve the overall adjuvant capacity. The aim of this review is to discuss the recent developments and applications of biodegradable nanodelivery systems that improve RNA-based vaccine delivery and enhance the immunological response against targeted diseases.

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A novel transcription factor UvCGBP1 regulates development and virulence of rice false smut fungus Ustilaginoidea virens

Virulence ◽

10.1080/21505594.2021.1936768 ◽

2021 ◽

Vol 12 (1) ◽

pp. 1563-1579

Author(s):

Xiaoyang Chen ◽

Pingping Li ◽

Hao Liu ◽

Xiaolin Chen ◽

Junbin Huang ◽

...

Keyword(s):

Transcription Factor ◽

Smut Fungus ◽

Ustilaginoidea Virens ◽

Rice False Smut ◽

False Smut

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Quantitative Proteomics Analysis Reveals the Function of the Putative Ester Cyclase UvEC1 in the Pathogenicity of the Rice False Smut Fungus Ustilaginoidea virens

International Journal of Molecular Sciences ◽

10.3390/ijms22084069 ◽

2021 ◽

Vol 22 (8) ◽

pp. 4069

Author(s):

Xiaoyang Chen ◽

Zhangxin Pei ◽

Pingping Li ◽

Xiabing Li ◽

Yuhang Duan ◽

...

Keyword(s):

Quantitative Proteomics ◽

Fungal Pathogens ◽

Protein Localization ◽

Proteomics Data ◽

Ustilaginoidea Virens ◽

Rice False Smut ◽

Oxidative Stresses ◽

Tandem Mass Tag ◽

Cyclase Domain ◽

False Smut

Rice false smut is a fungal disease distributed worldwide and caused by Ustilaginoidea virens. In this study, we identified a putative ester cyclase (named as UvEC1) as being significantly upregulated during U. virens infection. UvEC1 contained a SnoaL-like polyketide cyclase domain, but the functions of ketone cyclases such as SnoaL in plant fungal pathogens remain unclear. Deletion of UvEC1 caused defects in vegetative growth and conidiation. UvEC1 was also required for response to hyperosmotic and oxidative stresses and for maintenance of cell wall integrity. Importantly, ΔUvEC1 mutants exhibited reduced virulence. We performed a tandem mass tag (TMT)-based quantitative proteomic analysis to identify differentially accumulating proteins (DAPs) between the ΔUvEC1-1 mutant and the wild-type isolate HWD-2. Proteomics data revealed that UvEC1 has a variety of effects on metabolism, protein localization, catalytic activity, binding, toxin biosynthesis and the spliceosome. Taken together, our findings suggest that UvEC1 is critical for the development and virulence of U. virens.

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Gastrointestinal nematode infections in sheep raised in Botucatu, state of São Paulo, Brazil

Revista Brasileira de Parasitologia Veterinária ◽

10.1590/s1984-29612014058 ◽

2014 ◽

Vol 23 (3) ◽

pp. 348-354 ◽

Cited By ~ 13

Author(s):

Maurício Orlando Wilmsen ◽

Bruna Fernanda Silva ◽

César Cristiano Bassetto ◽

Alessandro Francisco Talamini do Amarante

Keyword(s):

Haemonchus Contortus ◽

Natural Infection ◽

Gastrointestinal Nematode ◽

Gastrointestinal Nematodes ◽

Sao Paulo ◽

São Paulo ◽

Mean Intensity ◽

Oesophagostomum Columbianum ◽

The Mean ◽

In Parenthesis

Gastrointestinal nematode infections were evaluated in sheep raised in Botucatu, state of São Paulo, Brazil between April 2008 and March 2011. Every month, two tracer lambs grazing with a flock of sheep were exposed to natural infection with gastrointestinal nematodes for 28 consecutive days. At the end of this period, the lambs were sacrificed for worm counts. Haemonchus contortus presented 100% of prevalence. The seasons exerted no significant influence on the mean intensity of H. contortus, which ranged from 315 worms in November 2010 to 2,5205 worms in January 2011. The prevalence of Trichostrongylus colubriformis was also 100%, with the lowest mean intensity (15 worms) recorded in February 2011 and the highest (9,760 worms) in October 2009. In the case of T. colubriformis, a significant correlation coefficient was found between worm counts vs. rainfall (r = −0.32; P <0.05). Three other nematodes species were found in tracer lambs, albeit in small numbers. Their prevalence and mean intensity (in parenthesis) were as follows: Oesophagostomum columbianum 28% (25.2), Cooperia curticei 7% (4.5) and Trichuris spp. 2% (1). In conclusion, the environmental conditions of the area proved to be highly favorable for the year-round transmission of H. contortus and T. colubriformis.

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