Trehalose: a mycogenic cell wall elicitor elicit resistance against leaf spot disease of broccoli and acts as a plant growth regulator

White leaf spot (Neopseudocercosporella capsellae) is a persistent and increasingly important foliar disease for canola (Brassica napus) across southern Australia. To define the role of plant growth stage on development of the disease epidemic, we first investigated the response of different canola cultivars (Scoop and Charlton) at five Sylvester-Bradley growth stages against N. capsellae. White leaf spot disease incidence and severity was dependent upon plant growth stage and cultivar (both P < 0.001), with plants being most susceptible at plant growth stage 1,00 (cotyledon stage) followed by plant growth stage 1,04 (4th leaf stage). Then, second, to quantify the impact of this disease on canola yield, we investigated the in-field relationship of white leaf spot disease incidence and severity with seed yield loss following artificial inoculation commencing at growth stage 1.04 (4th leaf stage). White leaf spot significantly (P < 0.001) reduced seed yield by 24% in N. capsellae inoculated field plots compared with non-inoculated field plots. We believe that this is the first time that serious seed yield losses from this disease have been quantified in-field. The current study demonstrates that N. capsellae disease incidence and severity on canola is determined by host growth stage at which pathogen infestation occurs. Emerging seedling cotyledons were highly susceptible, followed by less susceptibility in first true leaves to emerge but then increasing susceptibility as plants subsequently age towards the 4th leaf stage. This explains field observances where white leaf spot readily establishes on emerging seedlings and subsequently becomes more prevalent and severe as plants age.

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Screening of plant growth-promoting rhizobacteria as elicitor of systemic resistance against gray leaf spot disease in pepper

Applied Soil Ecology ◽

10.1016/j.apsoil.2013.07.016 ◽

2014 ◽

Vol 73 ◽

pp. 1-8 ◽

Cited By ~ 44

Author(s):

Jin-Soo Son ◽

Marilyn Sumayo ◽

Ye-Ji Hwang ◽

Byung-Soo Kim ◽

Sa-Youl Ghim

Keyword(s):

Plant Growth ◽

Leaf Spot ◽

Plant Growth Promoting Rhizobacteria ◽

Gray Leaf Spot ◽

Systemic Resistance ◽

Leaf Spot Disease ◽

Spot Disease ◽

Plant Growth Promoting ◽

Growth Promoting

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Disclosure of the Molecular Mechanism of Wheat Leaf Spot Disease Caused by Bipolaris sorokiniana through Comparative Transcriptome and Metabolomics Analysis

International Journal of Molecular Sciences ◽

10.3390/ijms20236090 ◽

2019 ◽

Vol 20 (23) ◽

pp. 6090 ◽

Cited By ~ 2

Author(s):

Wei Ye ◽

Taomei Liu ◽

Weimin Zhang ◽

Saini Li ◽

Muzi Zhu ◽

...

Keyword(s):

Cell Wall ◽

Leaf Spot ◽

Pathogenic Fungus ◽

Glycosyl Hydrolase ◽

Wheat Yield ◽

Bipolaris Sorokiniana ◽

Leaf Spot Disease ◽

Defensive Response ◽

Spot Disease ◽

Wheat Leaf

Wheat yield is greatly reduced because of the occurrence of leaf spot diseases. Bipolaris sorokiniana is the main pathogenic fungus in leaf spot disease. In this study, B. sorokiniana from wheat leaf (W-B. sorokiniana) showed much stronger pathogenicity toward wheat than endophytic B. sorokiniana from Pogostemon cablin (P-B. sorokiniana). The transcriptomes and metabolomics of the two B. sorokiniana strains and transcriptomes of B. sorokiniana-infected wheat leaves were comparatively analyzed. In addition, the expression levels of unigenes related to pathogenicity, toxicity, and cell wall degradation were predicted and validated by quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis. Results indicated that pathogenicity-related genes, especially the gene encoding loss-of-pathogenicity B (LopB) protein, cell wall-degrading enzymes (particularly glycosyl hydrolase-related genes), and killer and Ptr necrosis toxin-producing related unigenes in the W-B. sorokiniana played important roles in the pathogenicity of W-B. sorokiniana toward wheat. The down-regulation of cell wall protein, photosystem peptide, and rubisco protein suggested impairment of the phytosynthetic system and cell wall of B. sorokiniana-infected wheat. The up-regulation of hydrolase inhibitor, NAC (including NAM, ATAF1 and CUC2) transcriptional factor, and peroxidase in infected wheat tissues suggests their important roles in the defensive response of wheat to W-B. sorokiniana. This is the first report providing a comparison of the transcriptome and metabolome between the pathogenic and endophytic B. sorokiniana strains, thus providing a molecular clue for the pathogenic mechanism of W-B. sorokiniana toward wheat and wheat’s defensive response mechanism to W-B. sorokiniana. Our study could offer molecular clues for controlling the hazard of leaf spot and root rot diseases in wheat, thus improving wheat yield in the future.

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TWO NEW SEVERE LEAF SPOT DISEASE ON FOREST TREES OF JALGAON (MAHARASTRA) INDIA

FLORA AND FAUNA ◽

10.33451/florafauna.v23i2pp288-290 ◽

2017 ◽

Vol 23 (2) ◽

Author(s):

S. A. FIRDOUSI

Keyword(s):

Leaf Spot ◽

Fungal Disease ◽

Leaf Spot Disease ◽

Forest Trees ◽

First Report ◽

Spot Disease ◽

Severe Leaf

During the survey of the forest fungal disease, of Jalgaon district, two severe leaf spot diseases on Lannae coromandelica and ( Ougenia dalbergioides (Papilionaceae) were observed in Jalgaon, forest during July to September 2016-17. The casual organism was identified as Stigmina lanneae and Phomopsis sp. respectively1-4,7. These are first report from Jalgaon and Maharashtra state.

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