The Experts below are selected from a list of 252 Experts worldwide ranked by ideXlab platform
Mohammad Jamal Saharkhiz - One of the best experts on this subject based on the ideXlab platform.
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Effect of Zataria multiflora Boiss and Thymus vulgaris L. essential oils on black rot of ‘Washington Navel’ orange fruit
Postharvest Biology and Technology, 2016Co-Authors: Asghar Ramezanian, Moslem Azadi, Reza Mostowfizadeh-ghalamfarsa, Mohammad Jamal SaharkhizAbstract:Abstract This research was conducted to investigate the effects of Zataria multiflora and Thymus vulgaris essential oils on Alternaria decay (black rot) development and quality traits of ‘Washington Navel’ oranges both in vitro incubated at 25 °C for 7 days and in vivo at 5 °C for 60 days. Based on the results obtained from GC–MS analysis, thymol, carvacrol and para-cymene were the most abundant of all constituents in EO extracts of Z. multiflora and T. vulgaris. Alternaria citri growth was completely prevented at 300 and 400 μl l−1 in vitro concentrations of Z. multiflora and T. vulgaris EOs, respectively. Moreover, the fungal growth steadily decreased with increasing EOs concentration. Similar results were obtained from in vivo assays with 300 μl l−1 Z. multiflora EO and 400 μl l−1 T. vulgaris EO which showed the best effects in preventing fruit decay, without impairing fruit quality traits such as visual appearance, weight loss, firmness, peel color parameters (hue angle, chroma, and lightness), and juice chemical characteristics (endopolygalacturonase enzyme activity, antioxidant activity, total phenols, ascorbic acid and carotenoid content). The greater efficiency of Z. multiflora compared with T. vulgaris EO may be due to its higher concentration of the main constituents, especially thymol and carvacrol. Overall, Both Z. multiflora and T. vulgaris EOs could be an alternative to chemical fungicides without health risks for preserving orange fruit during cold storage.
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Effect of Zataria multiflora Boiss and Thymus vulgaris L. essential oils on black rot of 'Washington Navel' orange fruit
Postharvest Biology and Technology, 2016Co-Authors: Asghar Ramezanian, Moslem Azadi, Reza Mostowfizadeh-ghalamfarsa, Mohammad Jamal SaharkhizAbstract:This research was conducted to investigate the effects of Zataria multiflora and Thymus vulgaris essential oils on Alternaria decay (black rot) development and quality traits of 'Washington Navel' oranges both in vitro incubated at 25°C for 7 days and in vivo at 5°C for 60 days. Based on the results obtained from GC-MS analysis, thymol, carvacrol and para-cymene were the most abundant of all constituents in EO extracts of Z. multiflora and T. vulgaris. Alternaria citri growth was completely prevented at 300 and 400μll-1in vitro concentrations of Z. multiflora and T. vulgaris EOs, respectively. Moreover, the fungal growth steadily decreased with increasing EOs concentration. Similar results were obtained from in vivo assays with 300μll-1Z. multiflora EO and 400μll-1T. vulgaris EO which showed the best effects in preventing fruit decay, without impairing fruit quality traits such as visual appearance, weight loss, firmness, peel color parameters (hue angle, chroma, and lightness), and juice chemical characteristics (endopolygalacturonase enzyme activity, antioxidant activity, total phenols, ascorbic acid and carotenoid content). The greater efficiency of Z. multiflora compared with T. vulgaris EO may be due to its higher concentration of the main constituents, especially thymol and carvacrol. Overall, Both Z. multiflora and T. vulgaris EOs could be an alternative to chemical fungicides without health risks for preserving orange fruit during cold storage.
Kazuya Akimitsu - One of the best experts on this subject based on the ideXlab platform.
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Cloning and Sequence Analysis of Endopolygalacturonase Genes in Venturia nashicola and Venturia pirina
Jarq-japan Agricultural Research Quarterly, 2011Co-Authors: Hiroshi Katoh, Kazuya Akimitsu, Ayumi Yamada, Hideo IshiiAbstract:Genes encoding endopolygalacturonase (endoPG) were isolated from pathogens of the Asian pear scab, Venturia nashicola races 1, 2, 3, and 4, and European pear scab, V. pirina. The Vnpgr1 gene of the V. nashicola race 1 consists of a 1,116-bp open reading frame, encoding a protein of 372 amino acids with an estimated molecular mass of 37.5 kDa and an isoelectric point (pI) of 6.56. The sequences of Vnpg genes from different races and Vppg gene from V. pirina showed high identities (95-100%). The deduced amino acid sequence of the V. nashicola race 1 endoPG showed 63-68% identity to the endoPG sequences of Penicillium olsonii, Colletotrichum lindemuthianum, Cryphonectria parasitica, Fusarium oxysporum, Sclerotinia sclerotiorum, and Alternaria citri. The deduced amino acid sequence of the race 1 endoPG was identical to the N-terminal amino acid sequence of the previously purified endoPG enzyme from the mycelia of this race. The results of a southern blot analysis indicated that V. nashicola race 1 (isolate JS-115) had a single copy of the Vnpgr1. Restriction fragment length polymorphism (RFLP) analysis of the polymerase chain reaction (PCR) products of the endoPG gene digested with HincII, BspEI, and BsrGI was performed; thereafter, agarose gel electrophoresis yielded race-specific RFLP patterns.
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overexpression of citrus polygalacturonase inhibiting protein in citrus black rot pathogen Alternaria citri
Journal of Plant Physiology, 2007Co-Authors: Hiroshi Katoh, Hiroyuki Yamamoto, Sarunya Nalumpang, Kazuya AkimitsuAbstract:The rough lemon (Citrus jambhiri) gene encoding polygalacturonase-inhibiting protein (RlemPGIPA) was overexpressed in the pathogenic fungus Alternaria citri. The overexpression mutant AcOPI6 retained the ability to utilize pectin as a sole carbon source, and the overexpression of polygalacturonase-inhibiting protein did not have any effect on the growth of AcOPI6 in potato dextrose and pectin medium. The pathogenicity of AcOPI6 to cause a black rot symptom in citrus fruits was also unchanged. Polygalacturonase-inhibiting protein was secreted together with endopolygalacturonase into culture filtrates of AcOPI6, and oligogalacturonides were digested from polygalacturonic acid by both proteins in the culture filtrates. The reaction mixture containing oligogalacturonides possessed activity for induction of defense-related gene, RlemLOX, in rough lemon leaves.
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overexpression of a gene encoding a catabolite repression element in Alternaria citri causes severe symptoms of black rot in citrus fruit
Phytopathology, 2007Co-Authors: Hiroshi Katoh, Kouhei Ohtani, Hiroyuki Yamamoto, Kazuya AkimitsuAbstract:Katoh, H., Ohtani, K., Yamamoto, H., and Akimitsu, K. 2007. Overexpression of a gene encoding a catabolite repression element in Alternaria citri causes severe symptoms of black rot in citrus fruit. Phytopathology 97:557-563. A gene (AcCreA) encoding a catabolite repression element (CreA) with two zinc fingers of the Cys2His2 type was isolated from the postharvest fungal pathogen Alternaria citri. The AcCreA overexpression mutant AcOEC2 of A. citri showed normal growth on pectin medium and on segments of peel or the juice sac area from citrus fruit. Production of endopolygalacturonase, an essential virulence factor of this pathogen, was similar in AcOEC2 and the wild type in pectin-containing media. However, addition of glucose to the medium showed that carbon catabolite repression of endopolygalacturonase gene (Acpg1) expression, as well as endopolygalacturonase production, was lost in AcOEC2. The wild-type strain of A. citri causes rot mainly in the central axis of citrus fruit without development of rotting in the juice sac area; however, AcOEC2 caused severe black rot symptoms in both the central axis and juice sac areas. These results indicate that AcCreA-mediated catabolite repression controls the virulence or infection of this pathogen, and that the wild-type A. citri does not cause symptoms in the juice sac area due to carbon catabolite repression by sugars in the juice of the juice sac area.
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a virulence reducing mutation in the postharvest citrus pathogen Alternaria citri
Phytopathology, 2006Co-Authors: Hiroshi Katoh, A Isshiki, Hiroyuki Yamamoto, Akira Masunaka, Kazuya AkimitsuAbstract:ABSTRACT Alternaria citri causes Alternaria black rot, a postharvest fruit disease, on a broad range of citrus cultivars. We previously described that an endopolygalacturonase minus mutant of A. citri caused significantly less black rot in citrus fruit. To search for other essential factors causing symptoms in addition to endopolygalacturonase, a random mutation analysis of pathogenicity was performed using restriction enzyme-mediated integration. Three isolates among 1,694 transformants of A. citri had a loss in pathogenicity in a citrus peel assay, and one of these three mutants was a histidine auxotroph. Gene AcIGPD that encodes imidazole glycerol phosphate dehydratase, the sixth enzyme in the histidine biosynthetic pathway, was cloned, and the mutant containing the disrupted target gene, AcIGPD, caused less black rot.
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Characterization of cDNAs Encoding Two Distinct Miraculin-like Proteins and Stress-related Modulation of the Corresponding mRNAs in Citrus jambhiri Lush
Plant Molecular Biology, 2006Co-Authors: Shintaro Tsukuda, Hiroyuki Yamamoto, Kenji Gomi, Kazuya AkimitsuAbstract:Two distinct full-length cDNAs from rough lemon that encoded miraculin-like proteins were isolated by random amplification of cDNA ends (RACEs), based on sequence information from subtractive PCR previously described, and designated as RlemMLP1 and RlemMLP2 . The transcripts of both RlemMLP1 and RlemMLP2 were not detected in leaves, or stems but accumulated in fruits. Transcripts accumulated to higher levels in leaves after wounding, inoculation with conidia of Alternaria alternata , or treatment with methyl jasmonate vapors. Treatment with methyl salicylate antagonized the signaling pathway of wounding. Treatment with methyl salicylate at 2 h after wounding significantly reduced wounding-induced gene expression of both RlemMLP1 and RlemMLP2. Protein products of these genes were obtained by using a prokaryotic expression system, and had protease inhibitor activity. RlemMLP2, but not RlemMLP1, contained a thaumatin motif, and only RlemMLP2 showed anti-fungal activity against Alternaria citri . Cellular localization analysis with RlemMLP1 or RlemMLP2 fused to a green fluorescence protein gene following transient translation using a particle bombardment in onion cells indicated that both RlemMLP1 and RlemMLP2 were localized to the cytosol. These evidences revealed that rough lemon RlemMLPs are likely to have defensive function against pathogens at least when host cells are broken by their infections.
Asghar Ramezanian - One of the best experts on this subject based on the ideXlab platform.
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Effect of Zataria multiflora Boiss and Thymus vulgaris L. essential oils on black rot of ‘Washington Navel’ orange fruit
Postharvest Biology and Technology, 2016Co-Authors: Asghar Ramezanian, Moslem Azadi, Reza Mostowfizadeh-ghalamfarsa, Mohammad Jamal SaharkhizAbstract:Abstract This research was conducted to investigate the effects of Zataria multiflora and Thymus vulgaris essential oils on Alternaria decay (black rot) development and quality traits of ‘Washington Navel’ oranges both in vitro incubated at 25 °C for 7 days and in vivo at 5 °C for 60 days. Based on the results obtained from GC–MS analysis, thymol, carvacrol and para-cymene were the most abundant of all constituents in EO extracts of Z. multiflora and T. vulgaris. Alternaria citri growth was completely prevented at 300 and 400 μl l−1 in vitro concentrations of Z. multiflora and T. vulgaris EOs, respectively. Moreover, the fungal growth steadily decreased with increasing EOs concentration. Similar results were obtained from in vivo assays with 300 μl l−1 Z. multiflora EO and 400 μl l−1 T. vulgaris EO which showed the best effects in preventing fruit decay, without impairing fruit quality traits such as visual appearance, weight loss, firmness, peel color parameters (hue angle, chroma, and lightness), and juice chemical characteristics (endopolygalacturonase enzyme activity, antioxidant activity, total phenols, ascorbic acid and carotenoid content). The greater efficiency of Z. multiflora compared with T. vulgaris EO may be due to its higher concentration of the main constituents, especially thymol and carvacrol. Overall, Both Z. multiflora and T. vulgaris EOs could be an alternative to chemical fungicides without health risks for preserving orange fruit during cold storage.
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Effect of Zataria multiflora Boiss and Thymus vulgaris L. essential oils on black rot of 'Washington Navel' orange fruit
Postharvest Biology and Technology, 2016Co-Authors: Asghar Ramezanian, Moslem Azadi, Reza Mostowfizadeh-ghalamfarsa, Mohammad Jamal SaharkhizAbstract:This research was conducted to investigate the effects of Zataria multiflora and Thymus vulgaris essential oils on Alternaria decay (black rot) development and quality traits of 'Washington Navel' oranges both in vitro incubated at 25°C for 7 days and in vivo at 5°C for 60 days. Based on the results obtained from GC-MS analysis, thymol, carvacrol and para-cymene were the most abundant of all constituents in EO extracts of Z. multiflora and T. vulgaris. Alternaria citri growth was completely prevented at 300 and 400μll-1in vitro concentrations of Z. multiflora and T. vulgaris EOs, respectively. Moreover, the fungal growth steadily decreased with increasing EOs concentration. Similar results were obtained from in vivo assays with 300μll-1Z. multiflora EO and 400μll-1T. vulgaris EO which showed the best effects in preventing fruit decay, without impairing fruit quality traits such as visual appearance, weight loss, firmness, peel color parameters (hue angle, chroma, and lightness), and juice chemical characteristics (endopolygalacturonase enzyme activity, antioxidant activity, total phenols, ascorbic acid and carotenoid content). The greater efficiency of Z. multiflora compared with T. vulgaris EO may be due to its higher concentration of the main constituents, especially thymol and carvacrol. Overall, Both Z. multiflora and T. vulgaris EOs could be an alternative to chemical fungicides without health risks for preserving orange fruit during cold storage.
Hiroyuki Yamamoto - One of the best experts on this subject based on the ideXlab platform.
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overexpression of citrus polygalacturonase inhibiting protein in citrus black rot pathogen Alternaria citri
Journal of Plant Physiology, 2007Co-Authors: Hiroshi Katoh, Hiroyuki Yamamoto, Sarunya Nalumpang, Kazuya AkimitsuAbstract:The rough lemon (Citrus jambhiri) gene encoding polygalacturonase-inhibiting protein (RlemPGIPA) was overexpressed in the pathogenic fungus Alternaria citri. The overexpression mutant AcOPI6 retained the ability to utilize pectin as a sole carbon source, and the overexpression of polygalacturonase-inhibiting protein did not have any effect on the growth of AcOPI6 in potato dextrose and pectin medium. The pathogenicity of AcOPI6 to cause a black rot symptom in citrus fruits was also unchanged. Polygalacturonase-inhibiting protein was secreted together with endopolygalacturonase into culture filtrates of AcOPI6, and oligogalacturonides were digested from polygalacturonic acid by both proteins in the culture filtrates. The reaction mixture containing oligogalacturonides possessed activity for induction of defense-related gene, RlemLOX, in rough lemon leaves.
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overexpression of a gene encoding a catabolite repression element in Alternaria citri causes severe symptoms of black rot in citrus fruit
Phytopathology, 2007Co-Authors: Hiroshi Katoh, Kouhei Ohtani, Hiroyuki Yamamoto, Kazuya AkimitsuAbstract:Katoh, H., Ohtani, K., Yamamoto, H., and Akimitsu, K. 2007. Overexpression of a gene encoding a catabolite repression element in Alternaria citri causes severe symptoms of black rot in citrus fruit. Phytopathology 97:557-563. A gene (AcCreA) encoding a catabolite repression element (CreA) with two zinc fingers of the Cys2His2 type was isolated from the postharvest fungal pathogen Alternaria citri. The AcCreA overexpression mutant AcOEC2 of A. citri showed normal growth on pectin medium and on segments of peel or the juice sac area from citrus fruit. Production of endopolygalacturonase, an essential virulence factor of this pathogen, was similar in AcOEC2 and the wild type in pectin-containing media. However, addition of glucose to the medium showed that carbon catabolite repression of endopolygalacturonase gene (Acpg1) expression, as well as endopolygalacturonase production, was lost in AcOEC2. The wild-type strain of A. citri causes rot mainly in the central axis of citrus fruit without development of rotting in the juice sac area; however, AcOEC2 caused severe black rot symptoms in both the central axis and juice sac areas. These results indicate that AcCreA-mediated catabolite repression controls the virulence or infection of this pathogen, and that the wild-type A. citri does not cause symptoms in the juice sac area due to carbon catabolite repression by sugars in the juice of the juice sac area.
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a virulence reducing mutation in the postharvest citrus pathogen Alternaria citri
Phytopathology, 2006Co-Authors: Hiroshi Katoh, A Isshiki, Hiroyuki Yamamoto, Akira Masunaka, Kazuya AkimitsuAbstract:ABSTRACT Alternaria citri causes Alternaria black rot, a postharvest fruit disease, on a broad range of citrus cultivars. We previously described that an endopolygalacturonase minus mutant of A. citri caused significantly less black rot in citrus fruit. To search for other essential factors causing symptoms in addition to endopolygalacturonase, a random mutation analysis of pathogenicity was performed using restriction enzyme-mediated integration. Three isolates among 1,694 transformants of A. citri had a loss in pathogenicity in a citrus peel assay, and one of these three mutants was a histidine auxotroph. Gene AcIGPD that encodes imidazole glycerol phosphate dehydratase, the sixth enzyme in the histidine biosynthetic pathway, was cloned, and the mutant containing the disrupted target gene, AcIGPD, caused less black rot.
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Characterization of cDNAs Encoding Two Distinct Miraculin-like Proteins and Stress-related Modulation of the Corresponding mRNAs in Citrus jambhiri Lush
Plant Molecular Biology, 2006Co-Authors: Shintaro Tsukuda, Hiroyuki Yamamoto, Kenji Gomi, Kazuya AkimitsuAbstract:Two distinct full-length cDNAs from rough lemon that encoded miraculin-like proteins were isolated by random amplification of cDNA ends (RACEs), based on sequence information from subtractive PCR previously described, and designated as RlemMLP1 and RlemMLP2 . The transcripts of both RlemMLP1 and RlemMLP2 were not detected in leaves, or stems but accumulated in fruits. Transcripts accumulated to higher levels in leaves after wounding, inoculation with conidia of Alternaria alternata , or treatment with methyl jasmonate vapors. Treatment with methyl salicylate antagonized the signaling pathway of wounding. Treatment with methyl salicylate at 2 h after wounding significantly reduced wounding-induced gene expression of both RlemMLP1 and RlemMLP2. Protein products of these genes were obtained by using a prokaryotic expression system, and had protease inhibitor activity. RlemMLP2, but not RlemMLP1, contained a thaumatin motif, and only RlemMLP2 showed anti-fungal activity against Alternaria citri . Cellular localization analysis with RlemMLP1 or RlemMLP2 fused to a green fluorescence protein gene following transient translation using a particle bombardment in onion cells indicated that both RlemMLP1 and RlemMLP2 were localized to the cytosol. These evidences revealed that rough lemon RlemMLPs are likely to have defensive function against pathogens at least when host cells are broken by their infections.
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green fluorescent detection of fungal colonization and endopolygalacturonase gene expression in the interaction of Alternaria citri with citrus
Phytopathology, 2003Co-Authors: A Isshiki, Kouhei Ohtani, Hiroyuki Yamamoto, Kazuya AkimitsuAbstract:ABSTRACT Alternaria citri, a postharvest pathogen, produces endopolygalacturonase (endoPG) and causes black rot on citrus fruit. We previously described that an endoPG-disrupted mutant of Alternaria citri was significantly reduced in its ability to macerate plant tissue and cause black rot symptoms on citrus. In order to investigate colonization of citrus fruit tissues by Alternaria citri, pTEFEGFP carrying a green fluorescent protein (GFP) gene was introduced into wild-type Alternaria citri and its endoPG-disrupted mutant (M60). Green fluorescence was observed in spores, germ tubes, appressoria, and infection hyphae of transformants G1 (derived from wild type) and GM4 (derived from M60). Hyphae of G1 but not GM4 vertically penetrated the peel, but the hyphae of both G1 and GM4 spread equally in the juice sac area of citrus fruit. Green fluorescence of Alternaria citri transformant EPG7 carrying a GFP gene under control of the endoPG gene promoter of Alternaria citri was induced by pectin in the peel duri...
Moslem Azadi - One of the best experts on this subject based on the ideXlab platform.
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Effect of Zataria multiflora Boiss and Thymus vulgaris L. essential oils on black rot of ‘Washington Navel’ orange fruit
Postharvest Biology and Technology, 2016Co-Authors: Asghar Ramezanian, Moslem Azadi, Reza Mostowfizadeh-ghalamfarsa, Mohammad Jamal SaharkhizAbstract:Abstract This research was conducted to investigate the effects of Zataria multiflora and Thymus vulgaris essential oils on Alternaria decay (black rot) development and quality traits of ‘Washington Navel’ oranges both in vitro incubated at 25 °C for 7 days and in vivo at 5 °C for 60 days. Based on the results obtained from GC–MS analysis, thymol, carvacrol and para-cymene were the most abundant of all constituents in EO extracts of Z. multiflora and T. vulgaris. Alternaria citri growth was completely prevented at 300 and 400 μl l−1 in vitro concentrations of Z. multiflora and T. vulgaris EOs, respectively. Moreover, the fungal growth steadily decreased with increasing EOs concentration. Similar results were obtained from in vivo assays with 300 μl l−1 Z. multiflora EO and 400 μl l−1 T. vulgaris EO which showed the best effects in preventing fruit decay, without impairing fruit quality traits such as visual appearance, weight loss, firmness, peel color parameters (hue angle, chroma, and lightness), and juice chemical characteristics (endopolygalacturonase enzyme activity, antioxidant activity, total phenols, ascorbic acid and carotenoid content). The greater efficiency of Z. multiflora compared with T. vulgaris EO may be due to its higher concentration of the main constituents, especially thymol and carvacrol. Overall, Both Z. multiflora and T. vulgaris EOs could be an alternative to chemical fungicides without health risks for preserving orange fruit during cold storage.
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Effect of Zataria multiflora Boiss and Thymus vulgaris L. essential oils on black rot of 'Washington Navel' orange fruit
Postharvest Biology and Technology, 2016Co-Authors: Asghar Ramezanian, Moslem Azadi, Reza Mostowfizadeh-ghalamfarsa, Mohammad Jamal SaharkhizAbstract:This research was conducted to investigate the effects of Zataria multiflora and Thymus vulgaris essential oils on Alternaria decay (black rot) development and quality traits of 'Washington Navel' oranges both in vitro incubated at 25°C for 7 days and in vivo at 5°C for 60 days. Based on the results obtained from GC-MS analysis, thymol, carvacrol and para-cymene were the most abundant of all constituents in EO extracts of Z. multiflora and T. vulgaris. Alternaria citri growth was completely prevented at 300 and 400μll-1in vitro concentrations of Z. multiflora and T. vulgaris EOs, respectively. Moreover, the fungal growth steadily decreased with increasing EOs concentration. Similar results were obtained from in vivo assays with 300μll-1Z. multiflora EO and 400μll-1T. vulgaris EO which showed the best effects in preventing fruit decay, without impairing fruit quality traits such as visual appearance, weight loss, firmness, peel color parameters (hue angle, chroma, and lightness), and juice chemical characteristics (endopolygalacturonase enzyme activity, antioxidant activity, total phenols, ascorbic acid and carotenoid content). The greater efficiency of Z. multiflora compared with T. vulgaris EO may be due to its higher concentration of the main constituents, especially thymol and carvacrol. Overall, Both Z. multiflora and T. vulgaris EOs could be an alternative to chemical fungicides without health risks for preserving orange fruit during cold storage.