JOURNAL OF PHYTOPATHOLOGY
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2019
·Vol. 167
·期 10
·553-557
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IF 1.097
Xiaoyu Liang,Yun Peng,Yanchao Liu,Meng Wang,Ye Yang,Yu Zhang
The rubber tree ( Hevea brasiliensis ) is the only resource for commercial natural rubber production and thus has economic importance in Southeast Asia. A spot disease on the leaves of a rubber tree was first discovered in 2017 in Hainan, China. In this study, the fungal isolate MA1 from the infected tissues was determined to be a pathogen of the spot disease by satisfying Koch's postulates. The isolate MA1 was identified as Bipolaris bicolor based on the morphological characteristics and multigene phylogenetic analysis. Among fungicides, prochloraz, iprodione and pyraclostrobin significantly inhibited hyphal growth of B. bicolor under in vitro conditions. This study constitutes the first report on the association of B. bicolor with leaf spot disease of rubber trees worldwide.
研究领域:
植物病理学
·
真菌学
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产品关联
DOI
高影响因子
Microorganisms
·
2023
·Vol. 11
·期 6
·1431
·
IF 4.5
Guoyu Wei,Wei Zhao,Anlong Hu,Mingjian Ren,Yunxiao Huang,Huayang Xu
Sorghum bicoloris cultivated worldwide. Leaf spot of sorghum, which leads to leaf lesions and yield reduction, is a prevalent and serious disease in Guizhou Province, southwest China. In August 2021, new leaf spot symptoms were observed on sorghum leaves. In this study, traditional methods and modern molecular biology techniques were used to isolate and identify the pathogen. Sorghum inoculated with the isolate GY1021 resulted in reddish brown lesion that similar to symptoms observed in the field: the original isolate inoculated was reisolated and Koch’s postulates were fulfilled. Based on morphological features and phylogenetic analysis of the internal transcribed spacer (ITS) combined sequence with β-tubulin (TUB2) and translation elongation factor 1-α (TEF-1α) genes, the isolate was identified asFusarium thapsinum(Strain accession: GY 1021; GenBank Accession: ITS (ON882046),TEF-1α (OP096445), and β-TUB(OP096446)). Then, we studied the bioactivity of various natural products and microorganisms againstF. thapsinumusing the dual culture experiment. Carvacrol, 2-allylphenol, honokiol, and cinnamaldehyde showed excellent antifungal activity, with EC50values of 24.19, 7.18, 46.18, and 52.81 µg/mL, respectively. The bioactivity of six antagonistic bacteria was measured using a dual culture experiment and the mycelial growth rate method.Paenibacillus polymyxa,Bacillus amyloliquefaciensandBacillus velezensisdisplayed significant antifungal effects againstF. thapsinum. This study provides a theoretical basis for the green control of leaf spot of sorghum.Keywords:antagonistic bacteria;natural product;leaf spot;sorghum;F. thapsinum
研究领域:
植物病理学
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微生物学
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分子生物学
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产品关联
DOI
PubMed
高影响因子
PHYTOPATHOLOGY
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2023
·
IF 3.2
Mr. Jiayu Yin,Ms. Shuang Wu,Ms. Yongli Yang,Dr. Delu Wang,Prof. Yue Ma,Dr. Yongtian Zhao,Prof. Sujitraj Sheth,Miss Honglin Huang,Dr. Baoan Song,Dr. Zhuo Chen
Carvacrol expresses a wide range of biological activities, but the studies of its mechanisms focused on bacteria, mainly involving the destruction of the plasma membrane. In this study, carvacrol exhibited strong antifungal activities against several phytopathogenic fungi and determined a novel antifungal mechanism against Lasiodiplodia theobromae. RNA sequencing indicated that many genes of L. theobromae hyphae were predominately induced by carvacrol, particularly those involved in replication and transcription. Hyperchromic, hypsochromic, and bathochromic effects in the UV-visible absorption spectrum were observed following titration of calf thymus DNA (ctDNA) and carvacrol, which indicated the formation of a DNA–carvacrol complex. Circular dichroism (CD) spectroscopy indicated the response of DNA to carvacrol was similar to 4’, 6-diamidino-2-phenylindole (DAPI), but different from that of ethidium bromide (EB), implying the ionic bonds between carvacrol and ctDNA. Fluorescence spectrum (FS) analysis indicated that carvacrol quenched the fluorescence of double-stranded DNA more than single-stranded DNA, indicating that carvacrol mainly bound to double-stranded DNA. A displacement assay showed that carvacrol reduced the fluorescence intensity of the DNA–DAPI complex through competing with DAPI, but this did not occur for DNA–EB. FS assay revealed that carvacrol bound to AAA sequence on the minor groove of ds-oligonucleotides. The hydroxyl of carvacrol was verified to bind to ctDNA through a comparative test in which structural analogs of carvacrol, including thymol, 4-ethyl-1,2-dimethyl, etc. were analyzed. The current study indicated carvacrol can destruct plasma membranes and bind to the minor groove of DNA, which inhibited the fungal proliferation by disturbing the stability of dsDNA.
研究领域:
植物病理学
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分子生物学
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DOI
高影响因子
PEST MANAGEMENT SCIENCE
·
2024
·
IF 3.8
Xin-Yu Ji,Bing-Yi Wang,Yi-Feng Zhang,Yu-Jing Zhang,Ya-Jie Lai,Yang Yang,Xiang-Chen Wang,Su-Yan Wang,Pedro Laborda,Xin-Chi Shi
BACKGROUND Epicoccum sorghinum is a pathogenic fungus that causes leaf spot in a wide range of plants, including maize, and synthesizes the mycotoxin tenuazonic acid (TEA), which is carcinogenic. Despite the relevant economic and yield losses caused by E. sorghinum worldwide, methods for the control of this pathogen are lacking. RESULTS In this work, the efficacy of Bacillus -produced dipicolinic acid (DPA) for control of E. sorghinum was evaluated using in vitro and in vivo assays, and compared with the efficacy of three commercial fungicides, including carbendazim, prochloraz, and thiram. DPA inhibited E. sorghinum mycelial growth, and conidia germination, and produced important alterations in E. sorghinum hyphae. Interestingly, 10 mM DPA reduced TEA biosynthesis by 86.6%. Although DPA rapidly degraded on maize leaves, 10 mM DPA showed higher preventive (67.4% lesion length inhibition) and inhibitory (89.5% lesion length inhibition) efficacies for the control of E. sorghinum on maize leaves compared to the commercial fungicides. CONCLUSIONS Collectively, this study presents the first method for the control of E. sorghinum on maize and demonstrates that DPA application is a suitable approach to inhibit E. sorghinum symptoms in plants and TEA biosynthesis. © 2024 Society of Chemical Industry.
研究领域:
植物病理学
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农业科学
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毒理学
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产品关联
DOI
PubMed
高影响因子
PEST MANAGEMENT SCIENCE
·
2022
·Vol. 78
·期 11
·4557-4568
·
IF 4.462
Delong Wang,Min Li,Chunxia Yuan,Yali Fang,Zhijia Zhang
BACKGROUND The natural 1,8-dihydroxynaphthalene (DHN) melanin biosynthesis inhibitors (MBIs) are one of the promising approaches to the integrated management of plant diseases but have received scarce attention until now. Herein, to explore the natural DHN MBIs used in the control of northern corn leaf blight (NCLB), a library of 53 essential oil compounds was used to screen the MBIs against Exserohilum turcicum , the causal pathogen of NCLB, using tricyclazole as a reference compound. RESULTS The results of morphological change in the colony, thermogravimetric analysis, ultraviolet–visible spectroscopy, and transmission electron microscopy confirmed that guaiacol could effectively inhibit the melanin production at 50 μg/mL under in vitro conditions. The in vitro bioassay results indicated that this inhibition effect was concentration-dependent and the minimum inhibition concentration of guaiacol was 50 μg/mL. The in vivo experimental results demonstrated that guaiacol significantly inhibited appressorium formation and penetration on corn leaf sheaths at the concentration of 500 μg/mL. The pot experiment results revealed that there were no differences between guaiacol (500 μg/mL) and tricyclazole (100 μg/mL) in control efficacy. The enzymatic assay suggested that guaiacol might exert the activity through inhibiting DHN polymerization to form melanins, which was distinct from tricyclazole. CONCLUSIONS Taken together, this study screened out guaiacol as a natural MBI from 53 essential oil compounds and verified its effectiveness in the control of NCLB at 500 μg/mL. Above all, this research opened an avenue for exploring natural DHN MBIs in the integrated management of plant diseases. © 2022 Society of Chemical Industry.
研究领域:
植物病理学
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农学
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植物化学
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DOI
PubMed
高影响因子
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