scholarly journals Differential Responses of Cucurbita pepo to Podosphaera xanthii Reveal the Mechanism of Powdery Mildew Disease Resistance in Pumpkin

2021 ◽  
Vol 12 ◽  
Author(s):  
Shuwu Zhang ◽  
Jia Liu ◽  
Bingliang Xu ◽  
Jingjiang Zhou
Keyword(s):  
Gene Expression ◽  
Disease Resistance ◽  
Powdery Mildew ◽  
Signaling Pathway ◽  
Cucurbita Pepo ◽  
Total Phenolics ◽  
Defense Enzymes ◽  
Podosphaera Xanthii ◽  
Ros Scavenging ◽  
Powdery Mildew Disease

Powdery mildew is one of the most destructive diseases and the major cause to the production losses of cucurbit worldwide. A number of strategies have been developed and applied to discover suitable and safer methods to manage the occurrence of powdery mildew disease in pumpkins (Cucurbita pepo L.), but information is limited in screening tolerant germplasms and exploring their mechanisms in preventing the disease occurrence at physiological, biochemical, and molecular levels. Therefore, we investigated the responses of two commercial pumpkin cultivars to Podosphaera xanthii infection. Compared with mock-inoculated seedlings, few small and sparse powdery areas were observed on the leaves of the Sixing F1 cultivar on the 13th day after inoculation with P. xanthii, whereas a large number of diseased powdery areas and a layer of white powdery mildew were observed on the surface of Jin12 F1 leaves. The inoculation duration (7, 9, 11, and 13 days) significantly and continuously increased the disease incidence and index of pumpkin seedlings. The contents of H2O2, MDA, lignin, and total phenolics in the leaves of Sixing F1 and Jin12 F1 cultivars were markedly increased after inoculation with P. xanthii. However, the Sixing F1 cultivar exhibited much less reactive oxygen species (ROS) accumulation, a lower rate of lipid peroxidation, and a higher level of lignin and total phenolics contents after inoculation than the Jin12 F1 cultivar. Compared with untreated control pumpkin seedlings, significantly higher activities and gene expressions of the phenylpropanoids pathway enzymes (PAL and PPO), ROS scavenging defense enzymes (SOD, CAT, POD, and APX), and other salicylic acid (SA) signaling pathway marker genes were observed in the leaves of both cultivars after P. xanthii inoculation at different inoculation time points. These enhancements were significantly higher in Sixing F1 than Jin12 F1. Our results indicate that the Sixing F1 cultivar exhibited a much stronger ability in resistance to P. xanthii infection than the Jin12 F1 cultivar. Our results suggest that one possible mechanism of C. pepo cultivars to prevent the pathogen P. xanthii infection is by activating and enhancing the activity and gene expression of the phenylpropanoids pathway to synthesize phenolic substances and lignin, ROS scavenging defense enzymes to eliminate the harmful effects of ROS, and signaling pathway marker gene expression to improve plant disease resistance.

scholarly journals Mechanisms of different cultivars of Cucurbita pepo in resistance to Podosphaera xanthii infection through improvement of antioxidative defense system and gene expression

2020 ◽  
Author(s):  
Shuwu Zhang ◽  
Bingliang Xu ◽  
Jia Liu
Keyword(s):  
Gene Expression ◽  
Powdery Mildew ◽  
Cucurbita Pepo ◽  
Total Phenolics ◽  
Disease Incidence ◽  
Podosphaera Xanthii ◽  
Defense System ◽  
Pal Activity ◽  
Disease Occurrence ◽  
Ros Accumulation

Abstract Background: Powdery mildew is one of the world’s most destructive diseases of cucurbit and the major cause of losses in its production worldwide. A number of strategies have been developed and applied to discover some suitable and alternative safe methods to manage the powdery mildew disease occurrence, but little information is regarding to screen of resistant pumpkins (Cucurbita pepo L.) germplasm and explore the mechanisms of their preventing the disease occurrence at physiological, biochemical, and molecular levels. Therefore, we evaluated and determined the ability and mechanisms of two commercial pumpkin cultivars in resistance to Podosphaera xanthii infection. Results: Compared with mock-inoculated seedlings, small and sparse spots were observed on the cultivar of Sixing F1 leaves at the 13th day after inoculation with P. xanthii, whereas a large number of disease spots or a layer of white powdery mildew were observed on the surface of Jin12 F1 leaves. Increased the inoculation time (7, 9, 11 and 13 days) significantly and continuously increased the disease incidence and index of pumpkin seedlings after inoculation. The disease incidence and index of Jin12 F1 were significantly higher than the cultivar of Sixing F1. At Day 13, the disease incidence and index of Jin12 F1 were 80.0% and 72.6, whereas the cultivar of Sixing F1 was 22.3% and 17.7, respectively. The contents of H2O2, MDA, lignin and total phenolics in the leaves of Sixing F1 and Jin12 F1 were markedly accelerated after inoculation with P. xanthii. However, the cultivar of Sixing F1 exhibited less reactive oxygen species (ROS) accumulation, a lower rate of lipid peroxidation and higher level of lignin and total phenolics contents after inoculation, whereas the cultivar of Jin12 F1 exhibited higher level of ROS accumulation and rates of lipid peroxidation, and lower level of lignin and total phenolics contents. Higher activity and transcript level of antioxidant enzymes and gene of PAL expression were observed on different tissues of both cultivars after inoculated with P. xanthii. Compared with pumpkin seedlings that were inoculated with sterile water but not P. xanthii, the level of PAL activity and gene expression in leaves, petioles and stems of Sixing F1 and Jin12 F1 were upregulated and increased significantly at different time points after inoculation. The enhancement expression of PAL activity and gene in different tissues of Sixing F1 was significantly higher than Jin12 F1, and higher in leaves, lower in petioles and stems. Conclusions: Our results indicate that the cultivar of Sixing F1 exhibited the highest ability in resistance to P. xanthii infection in comparison to Jin12 F1, and one novel possible mechanism is related to the cultivars in resistance to P. xanthii infection by activating and enhancing the antioxidative defense system and gene expression to prevent the pathogens infection.

scholarly journals Powdery mildew disease resistance and marker-assisted screening at the Pm60 locus in wild diploid wheat Triticum urartu

2020 ◽  
Vol 8 (2) ◽  
pp. 252-259
Author(s):  
Fukai Zhao ◽  
Yinghui Li ◽  
Baoju Yang ◽  
Hongbo Yuan ◽  
Cong Jin ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Powdery Mildew ◽  
Diploid Wheat ◽  
Triticum Urartu ◽  
Powdery Mildew Disease

scholarly journals First Report of Powdery Mildew Caused by Podosphaera xanthii on Hulless Cucurbita pepo of Western District in China

Plant Disease ◽  
2020 ◽  
pp. PDIS-04-20-0703
Author(s):  
Q. L. Liang ◽  
L. X. Wei ◽  
B. L. Xu ◽  
L. L. Liu ◽  
A. Calderón-Urrea
Keyword(s):  
Powdery Mildew ◽  
Cucurbita Pepo ◽  
Podosphaera Xanthii ◽  
First Report

scholarly journals Transcriptomic analysis reveals distinct resistant response by physcion and chrysophanol against cucumber powdery mildew

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1991 ◽  
Author(s):  
Yanping Li ◽  
Shilin Tian ◽  
Xiaojun Yang ◽  
Xin Wang ◽  
Yuhai Guo ◽  
...  
Keyword(s):  
Gene Expression ◽  
Disease Resistance ◽  
Powdery Mildew ◽  
Differentially Expressed Genes ◽  
Expression Patterns ◽  
Defense Responses ◽  
Differentially Expressed ◽  
Rna Seq ◽  
Sequencing Data ◽  
Transcriptional Change

Physcion and chrysophanol induce defense responses against powdery mildew in cucumbers. The combination of these two compounds has synergistic interaction against the disease. We performed RNA-seq on cucumber leaf samples treated with physcion and chrysophanol alone and with their combination. We generated 17.6 Gb of high-quality sequencing data (∼2 Gb per sample) and catalogued the expressions profiles of 12,293 annotated cucumber genes in each sample. We identified numerous differentially expressed genes that exhibited distinct expression patterns among the three treatments. The gene expression patterns of the Chr and Phy treatments were more similar to each other than to the Phy × Chr treatment. The Phy × Chr treatment induced the highest number of differentially expressed genes. This dramatic transcriptional change after Phy × Chr treatment leaves reflects that physcion combined with chrysophanol treatment was most closely associated with induction of disease resistance. The analysis showed that the combination treatment caused expression changes of numerous defense-related genes. These genes have known or potential roles in structural, chemical and signaling defense responses and were enriched in functional gene categories potentially responsible for cucumber resistance. These results clearly demonstrated that disease resistance in cucumber leaves was significantly influenced by the combined physcion and chrysophanol treatment. Thus, physcion and chrysophanol are appealing candidates for further investigation of the gene expression and associated regulatory mechanisms related to the defense response.

Identification of powdery mildew disease on Cleome rutidosperma caused by Podosphaera xanthii in Odisha, India

2018 ◽  
Vol 71 (4) ◽  
pp. 627-629 ◽  
Author(s):  
Ashish Kumar Nayak ◽  
Nitesh Kumar Mund ◽  
Kishore Babu Bandamaravuri
Keyword(s):  
Powdery Mildew ◽  
Podosphaera Xanthii ◽  
Powdery Mildew Disease ◽  
Cleome Rutidosperma
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