scholarly journals Silencing Dicer-Like Genes Reduces Virulence and sRNA Generation in Penicillium italicum, the Cause of Citrus Blue Mold

Cells ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 363 ◽  
Author(s):  
Chunxiao Yin ◽  
Hong Zhu ◽  
Yueming Jiang ◽  
Yang Shan ◽  
Liang Gong
Keyword(s):  
Small Rnas ◽  
Northern Blot Analysis ◽  
Citrus Fruits ◽  
Penicillium Italicum ◽  
Blue Mold ◽  
Rnai Machinery ◽  
Valencia Orange ◽  
Stress Related Genes ◽  
Dicer Protein

The Dicer protein is one of the most important components of RNAi machinery because it regulates the production of small RNAs (sRNAs) in eukaryotes. Here, Dicer1-like gene (Pit-DCL1) and Dicer2-like gene (Pit-DCL2) RNAi transformants were generated via pSilent-1 in Penicillium italicum (Pit), which is the causal agent of citrus blue mold. Neither transformant showed a change in mycelial growth or sporulation ability, but the pathogenicity of the Pit-DCL2 RNAi transformant to citrus fruits was severely impaired, compared to that of the Pit-DCL1 RNAi transformant and the wild type. We further developed a citrus wound-mediated RNAi approach with a double-stranded fragment of Pit-DCL2 generated in vitro, which achieved an efficiency in reducing Pi-Dcl2 expression and virulence that was similar to that of protoplast-mediated RNAi in P. italicum, suggesting that this approach is promising in the exogenous application of dsRNA to control pathogens on the surface of citrus fruits. In addition, sRNA sequencing revealed a total of 69.88 million potential sRNAs and 12 novel microRNA-like small RNAs (milRNAs), four of which have been predicated on target innate immunity or biotic stress-related genes in Valencia orange. These data suggest that both the Pit-DCL1 and Pit-DCL2 RNAi transformants severely disrupted the biogenesis of the potential milRNAs, which was further confirmed for some milRNAs by qRT-PCR or Northern blot analysis. These data suggest the sRNAs in P. italicum that may be involved in a molecular virulence mechanism termed cross-kingdom RNAi (ck-RNAi) by trafficking sRNA from P. italicum to citrus fruits.

scholarly journals Limonin Enhances the Antifungal Activity of Eugenol Nanoemulsion against Penicillium Italicum In Vitro and In Vivo Tests

2021 ◽  
Vol 9 (5) ◽  
pp. 969
Author(s):  
Yi Li ◽  
Runan Zhao ◽  
Yan Li ◽  
Zhiqin Zhou
Keyword(s):  
Antifungal Activity ◽  
Pathogenic Fungus ◽  
Germination Rate ◽  
Challenge Test ◽  
Postharvest Quality ◽  
Citrus Fruits ◽  
Penicillium Italicum ◽  
Blue Mold

Penicillium italicum, the cause of citrus blue mold, is a pathogenic fungus that seriously affects the postharvest quality of citrus fruit and causes serious economic loss. In this study, a eugenol nanoemulsion containing limonin, an antimicrobial component from citrus seeds, was prepared using a high-pressure microfluidizer and the antifungal activity of the nanoemulsions against P. italicum was evaluated based on the conidial germination rate, mycelial growth, and scanning electron microscopy analysis. The results showed that the minimum inhibitory concentration and the inhibition rate of limonin-loaded eugenol nanoemulsion was 160 μg/mL and 59.21%, respectively, which was more potent than that of the limonin-free eugenol emulsion. After treatment with the nanoemulsions, the integrity of the P. italicum cell membrane was disrupted, the cell morphology was abnormal, and the leakage of nucleic acid and protein was observed. In addition, the challenge test on citrus fruits revealed that the limonin-loaded eugenol emulsion inhibited citrus infection for longer periods, with an infection rate of 29.2% after 5 days. The current research shows that nanoemulsions containing limonin and eugenol have effective antifungal activity against P. italicum, and may be used as a substitute for inhibiting blue mold in citrus fruits.

Inactivation of Penicillium digitatum and Penicillium italicum under In Vitro and In Vivo Conditions by Using UV-C Light

2013 ◽  
Vol 76 (10) ◽  
pp. 1761-1766 ◽  
Author(s):  
GÜLTEN TİRYAKİ GÜNDÜZ ◽  
FIKRET PAZIR
Keyword(s):  
Potato Dextrose Agar ◽  
Penicillium Digitatum ◽  
Citrus Fruits ◽  
Penicillium Italicum ◽  
Inoculation Methods ◽  
Penetration Ability ◽  
Working Distance ◽  
Uv C

In this study, the effects of UV-C on two of the main wound pathogens of citrus fruits, Penicillium digitatum and Penicillium italicum, were investigated with different inoculation methods in vitro and on oranges. P. digitatum and P. italicum spores were inoculated onto the surface of potato dextrose agar or oranges using spread, spot, wound, and piercing inoculation methods. UV-C treatment for 1 min from a working distance of 8 cm reduced the numbers of P. italicum and P. digitatum by about 3.9 and 5.3 log units, respectively, following spread inoculation under in vitro conditions. Significant reductions were obtained after 1-min UV-C treatments of the tested fungi following inoculation using the spread and spot methods. With inoculation by the wound and piercing methods, the tested spores were not inactivated completely even after 10- and 20-min treatment times, respectively. The application of UV-C (7.92 kJ m−2) on oranges reduced the percentage of oranges infected at least threefold compared with the rate of infection in the untreated control samples. UV-C irradiation could effectively inactivate spores of P. italicum and P. digitatum inoculated by the spread plate and spot inoculation methods under in vitro and in vivo conditions. On the other hand, because of the low penetration ability of UV-C light, the tested fungi were not completely inactivated following inoculation with the wound and piercing methods. UV-C treatment has potential for use in surface decontamination of citrus fruits.

scholarly journals Pinocembrin-7-Glucoside (P7G) Reduced Postharvest Blue Mold of Navel Orange by Suppressing Penicillium italicum Growth

2020 ◽  
Vol 8 (4) ◽  
pp. 536
Author(s):  
Chuying Chen ◽  
Jinyin Chen ◽  
Chunpeng Wan
Keyword(s):  
Electron Microscopy ◽  
Cell Membrane ◽  
Mycelial Growth ◽  
Cell Membrane Permeability ◽  
Wall Structure ◽  
Navel Orange ◽  
Penicillium Italicum ◽  
Blue Mold

The current study aimed to examine the in vitro and in vivo antifungal potential of pinocembrin-7-glucoside (P7G). P7G is an antifungal flavanone glycoside isolated from Ficus hirta Vahl. fruit against Penicillium italicum, a causative pathogen of blue mold disease in citrus fruit, and this study elucidates its possible action mechanism. P7G had a prominent mycelial growth inhibitory activity against P. italicum, with an observed half maximal effective concentration, minimum inhibitory concentration and minimum fungicidal concentration of 0.08, 0.2, and 0.8 g/L, respectively. The data from the in vivo test show that P7G significantly reduced blue mold symptoms and disease development of P. italicum in artificially inoculated “Newhall” navel orange. Compared to the control, increases in the cell membrane permeability of P. italicum supernatant and decreases in the intracellular constituent (e.g., soluble protein, reducing sugar, and total lipid) contents of P. italicum mycelia were identified, supporting scanning electron microscopy and transmission electron microscopy observations. Furthermore, a marked decline in both chitin and glucanase contents of P. italicum mycelia treated with P7G was induced by increasing its related degrading enzyme activities, suggesting that the cell wall structure was destroyed. The current study indicated that P7G may be a novel alternative for reducing blue mold by suppressing mycelial growth of P. italicum via a cell membrane/wall-targeting mechanism.

scholarly journals Use of Food Additives to Control Postharvest Citrus Blue Mold Disease

2017 ◽  
Vol 2 (3) ◽  
pp. 147-153 ◽  
Author(s):  
Askarne L. ◽  
H. Boubaker ◽  
E. H. Boudyach ◽  
A. Ait Ben Aoumar
Keyword(s):  
Boric Acid ◽  
Food Additives ◽  
Citrus Fruit ◽  
Colony Growth ◽  
Sodium Metabisulfite ◽  
Penicillium Italicum ◽  
Postharvest Diseases ◽  
Blue Mold

The aim of this study was to find an alternative to the chemical fungicide currently used in the control of postharvest citrus diseases. The antifungal activity of 10 salt compounds, considered as common food additives was assayed in in vitro and in vivo trials against Penicillium italicum, causal agent of citrus blue mold. Among the 10 tested salt compounds, sodium carbonate, ammonium carbonate, copper sulfate, sodium EDTA and sodium metabisulfite completely inhibited mycelial growth of Penicillium italicum at 20 mM. Colony growth of P. italicum on pH adjusted medium was evaluated. Results indicate that P. italicum can grow on both acidic and alkaline pH, with the optimum growth occurred in the range of 4.0 and 8.0. Results of the in vivo trials with tested salt compounds indicate that sodium metabisulfite (100 and 200 mM), boric acid (400 mM), sodium salicylate and sodium sulfite (200, 300 and 400 mM) completely inhibited blue mold development on citrus fruit. Boric acid (400 mM) and sodium metabisulfite (100 mM) gave the best results as they completely inhibited the fungus development without damaging fruit rind. Such healthy products therefore may represent a sustainable alternative to the use of chemical fungicides for controlling postharvest diseases of citrus fruit.

scholarly journals A Comparative Study of the Antioxidative Effects of Helichrysum italicum and Helichrysum arenarium Infusions

Antioxidants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 380
Author(s):  
Katja Kramberger ◽  
Zala Jenko Pražnikar ◽  
Alenka Baruca Arbeiter ◽  
Ana Petelin ◽  
Dunja Bandelj ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
High Performance ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Morphological Type ◽  
Mass Spectrometry Analysis ◽  
In Vitro Assays ◽  
Spectrometry Analysis ◽  
Stress Related Genes

Helichrysum arenarium (L.) Moench (abbrev. as HA) has a long tradition in European ethnomedicine and its inflorescences are approved as a herbal medicinal product. In the Mediterranean part of Europe, Helichrysum italicum (Roth) G. Don (abbrev. as HI) is more common. Since infusions from both plants are traditionally used, we aimed to compare their antioxidative potential using in vitro assays. Two morphologically distinct HI plants, HIa and HIb, were compared to a commercially available HA product. Genetic analysis using microsatellites confirmed a clear differentiation between HI and HA and suggested that HIb was a hybrid resulting from spontaneous hybridization from unknown HI subspecies. High-performance liquid chromatography–mass spectrometry analysis showed the highest amounts of hydroxycinnamic acids and total arzanol derivatives in HIa, whereas HIb was richest in monohydroxybenzoic acids, caffeic acids, and coumarins, and HA contained the highest amounts of flavonoids, especially flavanones. HIa exhibited the highest radical scavenging activity; it was more efficient in protecting different cell lines from induced oxidative stress and in inducing oxidative stress-related genes superoxide dismutase 1, catalase, and glutathione reductase 1. The antioxidative potential of HI was not only dependent on the morphological type of the plant but also on the harvest date, revealing important information for obtaining the best possible product. Considering the superior properties of HI compared to HA, the evaluation of HI as a medicinal plant could be recommended.

Sign in / Sign up

Export Citation Format

Share Document