Phytoalexins and Disease Resistance Mechanisms from a Perspective of Evolution and Adaptation

2008 ◽  
pp. 100-118
Author(s):  
Joseph Kuć
Keyword(s):  
Disease Resistance ◽  
Resistance Mechanisms

scholarly journals Identification and characterization of genes frequently responsive to Xanthomonas oryzae pv. oryzae and Magnaporthe oryzae infections in rice

BMC Genomics ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Weiwen Kong ◽  
Li Ding ◽  
Xue Xia
Keyword(s):  
Disease Resistance ◽  
Magnaporthe Oryzae ◽  
Enrichment Analysis ◽  
Defense Responses ◽  
Resistance Mechanisms ◽  
Xanthomonas Oryzae ◽  
Transcriptional Reprogramming ◽  
Go Enrichment ◽  
Phenylpropanoid Biosynthesis ◽  
Rice Disease

Abstract Background Disease resistance is an important factor that impacts rice production. However, the mechanisms underlying rice disease resistance remain to be elucidated. Results Here, we show that a robust set of genes has been defined in rice response to the infections of Xanthomonas oryzae pv. oryzae (Xoo) and Magnaporthe oryzae (Mor). We conducted a comprehensive analysis of the available microarray data from a variety of rice samples with inoculation of Xoo and Mor. A set of 12,932 genes was identified to be regulated by Xoo and another set of 2709 Mor-regulated genes was determined. GO enrichment analysis of the regulated genes by Xoo or Mor suggested mitochondrion may be an arena for the up-regulated genes and chloroplast be another for the down-regulated genes by Xoo or Mor. Cytokinin-related processes were most frequently repressed by Xoo, while processes relevant to jasmonic acid and abscisic acid were most frequently activated by Xoo and Mor. Among genes responsive to Xoo and Mor, defense responses and diverse signaling pathways were the most frequently enriched resistance mechanisms. InterPro annotation showed the zinc finger domain family, WRKY proteins, and Myb domain proteins were the most significant transcription factors regulated by Xoo and Mor. KEGG analysis demonstrated pathways including ‘phenylpropanoid biosynthesis’, ‘biosynthesis of antibiotics’, ‘phenylalanine metabolism’, and ‘biosynthesis of secondary metabolites’ were most frequently triggered by Xoo and Mor, whereas ‘circadian rhythm-plant’ was the most frequent pathway repressed by Xoo and Mor. Conclusions The genes identified here represent a robust set of genes responsive to the infections of Xoo and Mor, which provides an overview of transcriptional reprogramming during rice defense against Xoo and Mor infections. Our study would be helpful in understanding the mechanisms of rice disease resistance.

scholarly journals Wood Tannins - Isolation and Significance in Host Resistance to Verticillium Wilt Disease

1967 ◽  
Vol 20 (2) ◽  
pp. 475 ◽  
Author(s):  
TC Somers ◽  
AF Harrison
Keyword(s):  
Heart Disease ◽  
Disease Resistance ◽  
Verticillium Wilt ◽  
Host Resistance ◽  
Total Phenolics ◽  
Resistance Mechanisms ◽  
Wilt Disease ◽  
Fivefold Increase ◽  
Verticillium Albo Atrum

Apricot trees often recover from the "black heart" disease incited by the fungus Verticillium albo-atrum Reinke & Berthold, and a characteristic of such resistant trees is that the infected wood becomes dark brown to black in colour (Dufrenoy and Dufrenoy 1927). The fungus dies 1-6 months after it has colonized the wood (Taylor 1963). Analysis of total phenolics by the Folin-Denis assay showed an approximate fivefold increase (to about 60 mgjg wood) compared with that of uninfected wood of the same branch, and suggested their involvement in disease resistance mechanisms.

scholarly journals Zinc Induced Enzymatic Defense Mechanisms in Rhizoctonia Root Rot Infected Clusterbean Seedlings

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Neha Wadhwa ◽  
Udai Narayan Joshi ◽  
Naresh Mehta
Keyword(s):  
Enzyme Activity ◽  
Disease Resistance ◽  
Root Rot ◽  
Defense Mechanisms ◽  
Phenylalanine Ammonia Lyase ◽  
Resistance Mechanisms ◽  
Phenylpropanoid Metabolism ◽  
Rhizoctonia Root Rot ◽  
Tyrosine Ammonia Lyase ◽  
Wet Weight

This investigation was planned to determine the effect of different concentrations of zinc (Zn) on biochemical constituents of clusterbean, which play an important role in disease resistance mechanisms. Clusterbean seedlings were grown with 0, 10, or 20 mg Zn kg−1 soil treatments in earthen pots filled with 700 g inoculated soil. Soil was inoculated by pretreatment with 250 mg (wet weight) of Rhizoctonia inoculums per pot. A similar set was maintained in uninoculated soil. Root rot incidence decreased to 41 and 27 per cent with 10 and 20 mg Zn kg−1 soil treatments, respectively, as compared to 68 percent at control. Antioxidative enzyme activity (polyphenol oxidase, peroxidase, phenylalanine ammonia lyase, and tyrosine ammonia lyase) increased in inoculated seedlings and was increased further by 20 mg Zn kg−1 soil treatment. Antioxidative enzymes play an important role against fungal invasion, as peroxidase is involved in the formation of barrier via lignifications at the site of pathogen penetration. PAL and TAL play a key role in phenylpropanoid metabolism and could perform defense-related functions. Zn acts as a cofactor for these enzymes, so it can be concluded that Zn may be used as a soil-nutritive agent to increase resistance in plants against fungal diseases.

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