• Title/Summary/Keyword: plant protection

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Characteristics of the Infection of Tilletia laevis Kuhn (syn. Tilletia foetida (Wallr.) Liro.) in Compatible Wheat

  • Ren, Zhaoyu;Zhang, Wei;Wang, Mengke;Gao, Haifeng;Shen, Huimin;Wang, Chunping;Liu, Taiguo;Chen, Wanquan;Gao, Li
    • The Plant Pathology Journal
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    • v.37 no.5
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    • pp.437-445
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    • 2021
  • Tilletia laevis Kuhn (syn. Tilletia foetida (Wallr.) Liro.) causes wheat common bunt, which is one of the most devastating plant diseases in the world. Common bunt can result in a reduction of 80% or even a total loss of wheat production. In this study, the characteristics of T. laevis infection in compatible wheat plants were defined based on the combination of scanning electron microscopy, transmission electron microscopy and laser scanning confocal microscopy. We found T. laevis could lead to the abnormal growth of wheat tissues and cells, such as leakage of chloroplasts, deformities, disordered arrangements of mesophyll cells and also thickening of the cell wall of mesophyll cells in leaf tissue. What's more, T. laevis teliospores were found in the roots, stems, flag leaves, and glumes of infected wheat plants instead of just in the ovaries, as previously reported. The abnormal characteristics caused by T. laevis may be used for early detection of this pathogen instead of molecular markers in addition to providing theoretical insights into T. laevis and wheat interactions for breeding of common bunt resistance.

Molecular Mechanism of Plant Growth Promotion and Induced Systemic Resistance to Tobacco Mosaic Virus by Bacillus spp.

  • Wang, Shuai;Wu, Huijun;Qiao, Junqing;Ma, Lingli;Liu, Jun;Xia, Yanfei;Gao, Xuewen
    • Journal of Microbiology and Biotechnology
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    • v.19 no.10
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    • pp.1250-1258
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    • 2009
  • Bacillus spp., as a type of plant growth-promoting rhizobacteria (PGPR), were studied with regards promoting plant growth and inducing plant systemic resistance. The results of greenhouse experiments with tobacco plants demonstrated that treatment with the Bacillus spp. significantly enhanced the plant height and fresh weight, while clearly lowering the disease severity rating of the tobacco mosaic virus (TMV) at 28 days post-inoculation (dpi). The TMV accumulation in the young non-inoculated leaves was remarkably lower for all the plants treated with the Bacillus spp. An RT-PCR analysis of the signaling regulatory genes Coil and NPR1, and defense genes PR-1a and PR-1b, in the tobacco treated with the Bacillus spp. revealed an association with enhancing the systemic resistance of tobacco to TMV. A further analysis of two expansin genes that regulate plant cell growth, NtEXP2 and NtEXP6, also verified a concomitant growth promotion in the roots and leaves of the tobacco responding to the Bacillus spp.

Morphology and Molecular Characterization of Alternaria argyranthemi on Chrysanthemum coronarium in China

  • Luo, Huan;Xia, Zhen Zhou;Chen, Yun Yun;Zhou, Yi;Deng, Jian Xin
    • Mycobiology
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    • v.46 no.3
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    • pp.278-282
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    • 2018
  • Chrysanthemum coronarium is an economically important plant in Asia, and used medicinally, ornamentally and as a vegetable. In April 2017, leaf spot disease on C. coronarium was observed in Shiyan, Hubei, China. A single-spore isolate was obtained and identified based on morphology and sequence analysis using four regions (rDNA ITS, GAPDH, $EF-1{\alpha}$, and RPB2). The results indicated that the fungus is Alternaria argyranthemi. The pathogenicity tests revealed that the species could cause severe leaf spot and blight disease on the host. This is the first report of leaf spot disease on C. coronarium caused by A. argyranthemi in the world, which is also a new record of Alternaria species in China.

A Novel Protein Elicitor PeBL2, from Brevibacillus laterosporus A60, Induces Systemic Resistance against Botrytis cinerea in Tobacco Plant

  • Jatoi, Ghulam Hussain;Lihua, Guo;Xiufen, Yang;Gadhi, Muswar Ali;Keerio, Azhar Uddin;Abdulle, Yusuf Ali;Qiu, Dewen
    • The Plant Pathology Journal
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    • v.35 no.3
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    • pp.208-218
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    • 2019
  • Here, we reported a novel secreted protein elicitor PeBL2 from Brevibacillus laterosporus A60, which can induce hypersensitive response in tobacco (Nicotiana benthamiana). The ion-exchange chromatography, high-performance liquid chromatography (HPLC) and mass spectrometry were performed for identification of protein elicitor. The 471 bp PeBL2 gene produces a 17.22 kDa protein with 156 amino acids containing an 84-residue signal peptide. Consistent with endogenous protein, the recombinant protein expressed in Escherichia coli induced the typical hypersensitive response (HR) and necrosis in tobacco leaves. Additionally, PeBL2 also triggered early defensive response of generation of reactive oxygen species ($H_2O_2$ and $O_2{^-}$) and systemic resistance against of B. cinerea. Our findings shed new light on a novel strategy for biocontrol using B. laterosporus A60.

The MAP Kinase Kinase Gene AbSte7 Regulates Multiple Aspects of Alternaria brassicicola Pathogenesis

  • Lu, Kai;Zhang, Min;Yang, Ran;Zhang, Min;Guo, Qinjun;Baek, Kwang-Hyun;Xu, Houjuan
    • The Plant Pathology Journal
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    • v.35 no.2
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    • pp.91-99
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    • 2019
  • Mitogen-activated protein kinase (MAPK) cascades in fungi are ubiquitously conserved signaling pathways that regulate stress responses, vegetative growth, pathogenicity, and many other developmental processes. Previously, we reported that the AbSte7 gene, which encodes a mitogen-activated protein kinase kinase (MAPKK) in Alternaria brassicicola, plays a central role in pathogenicity against host cabbage plants. In this research, we further characterized the role of AbSte7 in the pathogenicity of this fungus using ${\Delta}AbSte7$ mutants. Disruption of the AbSte7 gene of A. brassicicola reduced accumulation of metabolites toxic to the host plant in liquid culture media. The ${\Delta}AbSte7$ mutants could not efficiently detoxify cruciferous phytoalexin brassinin, possibly due to reduced expression of the brassinin hydrolase gene involved in detoxifying brassinin. Disruption of the AbSte7 gene also severely impaired fungal detoxification of reactive oxygen species. AbSte7 gene disruption reduced the enzymatic activity of cell walldegrading enzymes, including cellulase, ${\beta}$-glucosidase, pectin methylesterase, polymethyl-galacturonase, and polygalacturonic acid transeliminase, during host plant infection. Altogether, the data strongly suggest the MAPKK gene AbSte7 plays a pivotal role in A. brassicicola during host infection by regulating multiple steps, and thus increasing pathogenicity and inhibiting host defenses.

Neopestalotiopsis Leaf Blight, an Emerging Concern on Leatherleaf Fern in Indonesia

  • Ani Widiastuti;Indah Khofifah Aruan;Alvina Clara Giovanni;Barokati Tsaniyah;Tri Joko;Achmadi Priyatmojo
    • Research in Plant Disease
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    • v.30 no.1
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    • pp.82-87
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    • 2024
  • Leatherleaf fern (Rumohra adiantiformis) is an important ornamental plant in Indonesia and global. Green fern leaves with bold dark green color with long shelf-life, attract florists as decoration. Indonesia is one important leatherleaf fern exporters, however currently an outbreak of leaf blight decreased production significantly. Initial symptom was reddish brown spots from edge of leaf, which was gradually followed by dark-brown necrotic lesions causing leaf blight and dried. This is a study to do Koch-Postulate approach and molecular identification, to identify the pathogen of the "new emerging disease" reported. Based on multigene analysis using primers from ITS, β-tub and tef1-α gene markers, the pathogen was identified as Neopestalotiopsis sp. All sequences have been deposited in GenBank with accession number of OR905551 (ITS), OR899817 (ßtubulin) and OR899816 (TEF). This Neopestalotiopsis leaf blight causes an emerging concern in leatherleaf fern in Indonesia and global biosecurity because it infected an export commodity.