scholarly journals Citrus Postharvest Green Mold: Recent Advances in Fungal Pathogenicity and Fruit Resistance

2020 ◽  
Vol 8 (3) ◽  
pp. 449 ◽  
Author(s):  
Yulin Cheng ◽  
Yunlong Lin ◽  
Haohao Cao ◽  
Zhengguo Li
Keyword(s):  
Molecular Mechanisms ◽  
Citrus Fruit ◽  
Plant Diseases ◽  
Postharvest Disease ◽  
Economic Losses ◽  
Fruit Storage ◽  
Green Mold ◽  
Recent Advances ◽  
Leaf Pathogen ◽  
Plant Pathogen Interactions

As the major postharvest disease of citrus fruit, postharvest green mold is caused by the necrotrophic fungus Penicillium digitatum (Pd), which leads to huge economic losses worldwide. Fungicides are still the main method currently used to control postharvest green mold in citrus fruit storage. Investigating molecular mechanisms of plant–pathogen interactions, including pathogenicity and plant resistance, is crucial for developing novel and safer strategies for effectively controlling plant diseases. Despite fruit–pathogen interactions remaining relatively unexplored compared with well-studied leaf–pathogen interactions, progress has occurred in the citrus fruit–Pd interaction in recent years, mainly due to their genome sequencing and establishment or optimization of their genetic transformation systems. Recent advances in Pd pathogenicity on citrus fruit and fruit resistance against Pd infection are summarized in this review.

scholarly journals Molecular Mechanisms Underlying Fungicide Resistance in Citrus Postharvest Green Mold

2021 ◽  
Vol 7 (9) ◽  
pp. 783
Author(s):  
Paloma Sánchez-Torres
Keyword(s):  
Fungicide Resistance ◽  
Molecular Mechanisms ◽  
Citrus Fruit ◽  
General Mechanism ◽  
Economic Losses ◽  
Fungal Virulence ◽  
Fruit Storage ◽  
Green Mold ◽  
Relevant Role ◽  
Molecular Aspects

The necrotrophic fungus Penicillium digitatum (Pd) is responsible for the green mold disease that occurs during postharvest of citrus and causes enormous economic losses around the world. Fungicides remain the main method used to control postharvest green mold in citrus fruit storage despite numerous occurrences of resistance to them. Hence, it is necessary to find new and more effective strategies to control this type of disease. This involves delving into the molecular mechanisms underlying the appearance of resistance to fungicides during the plant–pathogen interaction. Although mechanisms involved in resistance to fungicides have been studied for many years, there have now been great advances in the molecular aspects that drive fungicide resistance, which facilitates the design of new means to control green mold. A wide review allows the mechanisms underlying fungicide resistance in Pd to be unveiled, taking into account not only the chemical nature of the compounds and their target of action but also the general mechanism that could contribute to resistance to others compounds to generate what we call multidrug resistance (MDR) phenotypes. In this context, fungal transporters seem to play a relevant role, and their mode of action may be controlled along with other processes of interest, such as oxidative stress and fungal pathogenicity. Thus, the mechanisms for acquisition of resistance to fungicides seem to be part of a complex framework involving aspects of response to stress and processes of fungal virulence.

scholarly journals Comparative Proteomic Analysis of Plant–Pathogen Interactions in Resistant and Susceptible Poplar Ecotypes Infected with Botryosphaeria dothidea

2019 ◽  
Vol 109 (12) ◽  
pp. 2009-2021 ◽  
Author(s):  
Yongxia Li ◽  
Yuqian Feng ◽  
Quan Lü ◽  
Donghui Yan ◽  
Zhenyu Liu ◽  
...  
Keyword(s):  
Atp Synthase ◽  
Plant Pathogen ◽  
Molecular Mechanisms ◽  
Triosephosphate Isomerase ◽  
Hydrolytic Enzymes ◽  
Economic Losses ◽  
Botryosphaeria Dothidea ◽  
Bisphosphate Carboxylase ◽  
Populus Tomentosa Carr ◽  
Plant Pathogen Interactions

Poplar are important forestry species in China, but the Botryosphaeria dothidea pathogen causes serious economic losses worldwide. To identify candidate B. dothidea resistance proteins and explore the molecular mechanisms involved in poplar–pathogen interactions, proteomic responses of stem samples from resistant and susceptible poplar ecotypes to B. dothidea were investigated using nanoflow liquid chromatography-tandem mass spectrometry with label-free quantitative analysis. We identified 588 proteins, divided into 21 biological process categories including 48 oxidoreductases, 72 hydrolytic enzymes, 80 metabolic enzymes, and 29 proteins of unknown function. Differential proteome analysis revealed large differences between resistant Populus tomentosa Carr and susceptible Populus beijingensis Hsu ecotypes before and after inoculation. Among 102 identified proteins, 22 were highly upregulated in the resistant genotype but downregulated in the susceptible genotype. Proteins induced in P. tomentosa Carr in response to B. dothidea are associated with plant defenses including oxidoreductase activity (catalase, isocitrate dehydrogenase, and superoxide dismutase), phenylpropanoid biosynthesis and phenylalanine metabolism (alcohol dehydrogenase), photosynthesis (ATP synthase subunit alpha, ATP synthase gamma chain, photosystem I P700 chlorophyll a apoprotein A2, photosystem II CP47 chlorophyll apoprotein), carbon fixation (pyruvate kinase, triosephosphate isomerase, malic enzyme, phosphoglycerate kinase, ribulose-1,5-bisphosphate carboxylase, and ribulose bisphosphate carboxylase small chain), and glycolysis/gluconeogenesis (fructose-bisphosphate aldolase). Kyoto Encyclopedia of Genes and Genomes pathway analysis identified 168 proteins related to metabolic pathways, 41 proteins related to the biosynthesis of phenylpropanoids, and 36 proteins related to the biosynthesis of plant hormones, the biosynthesis of alkaloids derived from ornithine, lysine, and nicotinic acid, and photosynthesis in response to B. dothidea. Our findings provide insight into plant–pathogen interactions in resistant and susceptible poplar ecotypes infected with B. dothidea and could assist the development of novel strategies for fighting poplar canker disease.

scholarly journals Synthesis and Antifungal Activities of Cinnamaldehyde Derivatives against Penicillium digitatum Causing Citrus Green Mold

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Zengyu Gan ◽  
Jianping Huang ◽  
Jinyin Chen ◽  
Muhammad Farrukh Nisar ◽  
Wenwen Qi
Keyword(s):  
Reducing Sugars ◽  
Citrus Fruit ◽  
Pathogenic Fungi ◽  
Penicillium Digitatum ◽  
Economic Losses ◽  
Fungal Cell ◽  
Green Mold ◽  
Antifungal Potential ◽  
Germination And Growth ◽  
Derivatives Of

Penicillium digitatum (green mold) is pathogenic fungi and causes citrus fruit postharvest rotting that leads to huge economic losses across the world. The current study was aimed to develop a new derivative of cinnamaldehyde (4-methoxycinnamaldehyde) through the cross-hydroxyaldehyde condensation method with benzaldehyde substituted by a benzene ring under the catalysis of alkaline reagent and, moreover, to test their antifungal potential against P. digitatum, the major citrus fruit rotting fungi. Multiple derivatives of cinnamaldehyde viz. 4-nitro CA, 4-chloro CA, 4-bromo CA, 4-methyl CA, 4-methoxy CA, and 2,4-dimethoxy CA were synthesized in the current study whereas the 4-methoxy CA showed highest antifungal actions for citrus fruit postharvest rotting fungi P. digitatum. Moreover, 4-methoxy CA was found to reduce the spore germination and growth by damaging the fungal cell membrane, as well as declined the levels of reducing sugars.

scholarly journals Mixed Infections of Plant Viruses in Crops: Solo vs. Group Game

Proceedings ◽  
2020 ◽  
Vol 50 (1) ◽  
pp. 94
Author(s):  
Inmaculada Ferriol ◽  
Ornela Chase ◽  
María Luisa Domingo-Calap ◽  
Juan José López-Moya
Keyword(s):  
Molecular Mechanisms ◽  
Viral Infections ◽  
Complex Diseases ◽  
Plant Viruses ◽  
Plant Diseases ◽  
Control Measures ◽  
Effective Control ◽  
Economic Losses ◽  
Multiple Infections ◽  
Mixed Infections

Plant diseases are responsible for considerable economic losses in agriculture worldwide. Recent surveys and metagenomics approaches reveal a higher than expected incidence of complex diseases, like those caused by mixed viral infections. Particularly, frequent cases of mixed infections are co-infections or superinfections of plant viruses belonging to different genera in the families Potyviridae (Ipomovirus or Potyvirus) and Closteroviridae (Crinivirus). The outcome of such multiple infections could modify viral traits, such as host range, titer, tissue and cell tropisms, and even vector preference and transmission rates. Therefore, we believe that understanding the virus–virus, virus–host, and virus–vector interactions would be crucial for developing effective control measures. Since there is still limited knowledge about the molecular mechanisms underlying the different interactions, and how they might contribute to specific diseases in mixed infection, we are analyzing ipomovirus–crinivirus and potyvirus–crinivirus pathosystems, to better understand single and mixed infections in selected susceptible hosts (Cucurbitaceae and Convolvulaceae plants), also incorporating in the study the interactions with insect vectors (whiteflies and aphids). Among other strategies, we are engineering new biotechnological tools, to explore the molecular biology and transmission mechanisms of several viruses implicated in complex diseases, and we are also addressing the possibility to produce virus-like particles (VLPs) through transient expression of the CP of different viruses in Nicotiana benthamiana plants, with the aim to study requirements for virion formation and determinants of transmission. Work supported by project AGL2016-75529-R and grant “Severo-Ochoa” SEV-2015-0533.

scholarly journals The Effect of Gut Bacteria on the Physiology of Red Palm Weevil, Rhynchophorus ferrugineus Olivier and Their Potential for the Control of This Pest

Insects ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 594
Author(s):  
Qian-Xia Liu ◽  
Zhi-Ping Su ◽  
Hui-Hui Liu ◽  
Sheng-Ping Lu ◽  
Bing Ma ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Management Strategies ◽  
Gut Bacteria ◽  
Economic Losses ◽  
Rhynchophorus Ferrugineus ◽  
Intestinal Immunity ◽  
Red Palm Weevil ◽  
Nutrient Metabolism ◽  
Palm Weevil

Red Palm Weevil (RPW), Rhynchophorus ferrugineus Olivier, is a notorious pest, which infests palm trees and has caused great economic losses worldwide. At present, insecticide applications are still the main way to control this pest. However, pesticide resistance has been detected in the field populations of RPW. Thus, future management strategies based on the novel association biological control need be developed. Recent studies have shown that the intestinal tract of RPW is often colonized by multiple microbial species as mammals and model insects, and gut bacteria have been found to promote the growth, development and immune activity of RPW larvae by modulating nutrient metabolism. Furthermore, two peptidoglycan recognition proteins (PGRPs), PGRP-LB and PGRP-S1, can act as the negative regulators to modulate the intestinal immunity to maintain the homeostasis of gut bacteria in RPW larvae. Here, we summarized the current knowledge on the gut bacterial composition of RPW and their impact on the physiological traits of RPW larvae. In contrast with metazoans, it is much easier to make genetic engineered microbes to produce some active molecules against pests. From this perspective, because of the profound effects of gut bacteria on host phenotypes, it is promising to dissect the molecular mechanisms behind their effect on host physiology and facilitate the development of microbial resource-based management methods for pest control.

scholarly journals RNAseq Reveals Differential Gene Expression Contributing to Phytophthora nicotianae Adaptation to Partial Resistance in Tobacco

Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 656
Author(s):  
Jing Jin ◽  
Rui Shi ◽  
Ramsey Steven Lewis ◽  
Howard David Shew
Keyword(s):  
Partial Resistance ◽  
Molecular Mechanisms ◽  
Biological Activities ◽  
Effective Means ◽  
Phytophthora Nicotianae ◽  
Economic Losses ◽  
Black Shank ◽  
Differential Gene ◽  
Go Terms

Phytophthora nicotianae is a devastating oomycete plant pathogen with a wide host range. On tobacco, it causes black shank, a disease that can result in severe economic losses. Deployment of host resistance is one of the most effective means of controlling tobacco black shank, but adaptation to complete and partial resistance by P. nicotianae can limit the long-term effectiveness of the resistance. The molecular basis of adaptation to partial resistance is largely unknown. RNAseq was performed on two isolates of P. nicotianae (adapted to either the susceptible tobacco genotype Hicks or the partially resistant genotype K 326 Wz/Wz) to identify differentially expressed genes (DEGs) during their pathogenic interactions with K 326 Wz/Wz and Hicks. Approximately 69% of the up-regulated DEGs were associated with pathogenicity in the K 326 Wz/Wz-adapted isolate when sampled following infection of its adapted host K 326 Wz/Wz. Thirty-one percent of the up-regulated DEGs were associated with pathogenicity in the Hicks-adapted isolate on K 326 Wz/Wz. A broad spectrum of over-represented gene ontology (GO) terms were assigned to down-regulated genes in the Hicks-adapted isolate. In the host, a series of GO terms involved in nuclear biosynthesis processes were assigned to the down-regulated genes in K 326 Wz/Wz inoculated with K 326 Wz/Wz-adapted isolate. This study enhances our understanding of the molecular mechanisms of P. nicotianae adaptation to partial resistance in tobacco by elucidating how the pathogen recruits pathogenicity-associated genes that impact host biological activities.

scholarly journals Morphology Characterization, Molecular Phylogeny, and Pathogenicity of Diaporthe passifloricola on Citrus reticulata cv. Nanfengmiju in Jiangxi Province, China

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 218
Author(s):  
Chingchai Chaisiri ◽  
Xiang-Yu Liu ◽  
Wei-Xiao Yin ◽  
Chao-Xi Luo ◽  
Yang Lin
Keyword(s):  
Phylogenetic Analyses ◽  
Citrus Fruit ◽  
Epidemiological Studies ◽  
Morphological Characterization ◽  
Jiangxi Province ◽  
Citrus Reticulata ◽  
Fruit Storage ◽  
Pathogenicity Tests ◽  
Rot Disease ◽  
Morphology Characterization

The Nanfengmiju (Citrus reticulata cv. Nanfengmiju), a high-quality local variety of mandarin, is one of the major fruit crops in Jiangxi Province, China. Citrus melanose and stem-end rot, two common fungal diseases of Nanfengmiju, are both caused by Diaporthe spp. (syn. Phomopsis spp.). Identification of the Diaporthe species is essential for epidemiological studies, quarantine measures, and management of diseases caused by these fungi. Melanose disease was observed on Nanfengmiju fruit in Jiangxi Province of China in 2016. Based on morphological characterization and multi-locus phylogenetic analyses, three out of 39 isolates from diseased samples were identified as D. passifloricola. Since these three isolates did not cause melanose on citrus fruit in the pathogenicity tests, they were presumed to be endophytic fungi present in the diseased tissues. However, our results indicate that D. passifloricola may persist as a symptom-less endophyte in the peel of citrus fruit, yet it may cause stem-end if it invades the stem end during fruit storage. To the best of our knowledge, this is the first report of D. passifloricola as the causal agent of the stem-end rot disease in Citrusreticulata cv. Nanfengmiju.

scholarly journals AI-Driven Framework for Recognition of Guava Plant Diseases through Machine Learning from DSLR Camera Sensor Based High Resolution Imagery

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3830
Author(s):  
Ahmad Almadhor ◽  
Hafiz Tayyab Rauf ◽  
Muhammad Ikram Ullah Lali ◽  
Robertas Damaševičius ◽  
Bader Alouffi ◽  
...  
Keyword(s):  
Machine Learning ◽  
High Resolution ◽  
Color Difference ◽  
Plant Diseases ◽  
Economic Losses ◽  
Production Loss ◽  
Postharvest Diseases ◽  
Tropical Regions ◽  
Guava Fruit ◽  
Tree Classifier

Plant diseases can cause a considerable reduction in the quality and number of agricultural products. Guava, well known to be the tropics’ apple, is one significant fruit cultivated in tropical regions. It is attacked by 177 pathogens, including 167 fungal and others such as bacterial, algal, and nematodes. In addition, postharvest diseases may cause crucial production loss. Due to minor variations in various guava disease symptoms, an expert opinion is required for disease analysis. Improper diagnosis may cause economic losses to farmers’ improper use of pesticides. Automatic detection of diseases in plants once they emerge on the plants’ leaves and fruit is required to maintain high crop fields. In this paper, an artificial intelligence (AI) driven framework is presented to detect and classify the most common guava plant diseases. The proposed framework employs the ΔE color difference image segmentation to segregate the areas infected by the disease. Furthermore, color (RGB, HSV) histogram and textural (LBP) features are applied to extract rich, informative feature vectors. The combination of color and textural features are used to identify and attain similar outcomes compared to individual channels, while disease recognition is performed by employing advanced machine-learning classifiers (Fine KNN, Complex Tree, Boosted Tree, Bagged Tree, Cubic SVM). The proposed framework is evaluated on a high-resolution (18 MP) image dataset of guava leaves and fruit. The best recognition results were obtained by Bagged Tree classifier on a set of RGB, HSV, and LBP features (99% accuracy in recognizing four guava fruit diseases (Canker, Mummification, Dot, and Rust) against healthy fruit). The proposed framework may help the farmers to avoid possible production loss by taking early precautions.

scholarly journals Analysis of the Role of Bradysiaimpatiens (Diptera: Sciaridae) as a Vector Transmitting Peanut Stunt Virus on the Model Plant Nicotiana benthamiana

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1546
Author(s):  
Marta Budziszewska ◽  
Patryk Frąckowiak ◽  
Aleksandra Obrępalska-Stęplowska
Keyword(s):  
Nicotiana Benthamiana ◽  
Molecular Mechanisms ◽  
Virus Transmission ◽  
Pathogenic Fungi ◽  
Economic Losses ◽  
Fungus Gnats ◽  
Droplet Pcr ◽  
Viral Coat ◽  
Peanut Stunt Virus

Bradysia species, commonly known as fungus gnats, are ubiquitous in greenhouses, nurseries of horticultural plants, and commercial mushroom houses, causing significant economic losses. Moreover, the insects from the Bradysia genus have a well-documented role in plant pathogenic fungi transmission. Here, a study on the potential of Bradysia impatiens to acquire and transmit the peanut stunt virus (PSV) from plant to plant was undertaken. Four-day-old larvae of B. impatiens were exposed to PSV-P strain by feeding on virus-infected leaves of Nicotiana benthamiana and then transferred to healthy plants in laboratory conditions. Using the reverse transcription-polymerase chain reaction (RT-PCR), real-time PCR (RT-qPCR), and digital droplet PCR (RT-ddPCR), the PSV RNAs in the larva, pupa, and imago of B. impatiens were detected and quantified. The presence of PSV genomic RNA strands as well as viral coat protein in N. benthamiana, on which the viruliferous larvae were feeding, was also confirmed at the molecular level, even though the characteristic symptoms of PSV infection were not observed. The results have shown that larvae of B. impatiens could acquire the virus and transmit it to healthy plants. Moreover, it has been proven that PSV might persist in the insect body transstadially. Although the molecular mechanisms of virion acquisition and retention during insect development need further studies, this is the first report on B. impatiens playing a potential role in plant virus transmission.

scholarly journals Efficacy and Application Strategies for Propiconazole as a New Postharvest Fungicide for Managing Sour Rot and Green Mold of Citrus Fruit

Plant Disease ◽  
2012 ◽  
Vol 96 (2) ◽  
pp. 235-242 ◽  
Author(s):  
A. H. McKay ◽  
H. Förster ◽  
J. E. Adaskaveg
Keyword(s):  
Management Practices ◽  
Citrus Fruit ◽  
The United States ◽  
Optimal Time ◽  
Inoculum Concentration ◽  
Time Of Application ◽  
Sour Rot ◽  
Green Mold ◽  
Highly Effective ◽  
Moderately Resistant

Few postharvest treatments are available for managing sour rot of citrus caused by Galactomyces citri-aurantii and they are generally not very effective. The demethylation-inhibiting (DMI) triazole fungicides propiconazole and cyproconazole were found to be highly effective and more efficacious than other DMIs evaluated, such as metconazole and tebuconazole, in reducing postharvest sour rot of citrus. Additional studies were conducted with propiconazole as a postharvest treatment because it has favorable toxicological characteristics for food crop registration in the United States and the registrant supports a worldwide registration. Regression and covariance analyses were performed to determine optimal time of application after inoculation and fungicide rate. In laboratory studies, decay incidence increased when propiconazole applications were delayed from 8 to 24 h (lemon) or 18 to 42 h (grapefruit) after inoculation. Effective rates of the fungicide were 64 to 512 μg/ml and were dependent on inoculum concentration of the sour rot pathogen and on the type of citrus fruit. Propiconazole was found to be compatible with sodium hypochlorite at 100 μg/ml and 1 to 3% sodium bicarbonate without loss of efficacy for decay control on lemon. The addition of hydrogen peroxide/peroxyacetic acid at 80 μg/ml slightly decreased the effectiveness of propiconazole. Heated (48°C) solutions of propiconazole did not significantly improve the efficacy compared with solutions at 22°C. In experimental packing-line studies, aqueous in-line drenches applied alone or followed by applications of the fungicide in storage or packing fruit coatings were highly effective, reducing sour rot to between 0 and 1.2% compared with 83.8% decay incidence in the control when treatments were made up to 16 h after inoculation. When the fungicide was applied in either fruit coating, decay was only reduced to 49.1 to 57.1% incidence. Tank mixtures of propiconazole with the citrus postharvest fungicides fludioxonil and azoxystrobin were highly effective in reducing green mold caused by isolates of Penicillium digitatum sensitive or moderately resistant to imazalil and sour rot. Propiconazole will be an important postharvest fungicide for managing sour rot of citrus and potentially can be integrated into current management practices to reduce postharvest crop losses caused by DMI-sensitive isolates of P. digitatum.

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