Genetic defense analysis of tomatoes in response to early blight disease, Alternaria alternata

Golparvar

Biotechnology & Biotechnological Equipment

et al. 2019

Self Cite

Cucumber (Cucumis sativus L.) damping-off disease caused by Phytophthora melonis is a limiting factor affecting cucurbit production. This study assessed a collection of 38 domestic and exotic commercial cucumber genotypes for damping-off resistance at transplanting and 50% flowering. Plants were classified using a four-score scale, the average damping-off percentage ranging from 7.92% (resistant) to 88.01% [highly susceptible (HS)]. Most of the genotypes were susceptible and HS to P. melonis. These genotypes were analyzed with 15 inter-simple sequence repeat (ISSR) markers. A total of 317 bands were produced, of which 297 bands (93.69%) were polymorphic. The primer ISSR29 possessed the highest resolving power, polymorphic information content and marker index value, which could be the most informative primer for distinguishing cucumber genotypes. Cluster analysis and principal component analysis were carried out and there was a probable connection between cucumber genotypes and resistance level against P. melonis, indicating possible application for ISSR in studying disease resistance of cucumber and producing cultivars that resist damping-off. The expression of three candidate genes probably involved in the defence against P. melonis was quantified by quantitative real-time polymerase chain reaction in five cucumber genotypes showing different susceptibility to the pathogen. CsWRKY20, CsLecRK6.1 and LOX1 genes were differentially expressed depending on genotype in early stages of infection. LOX1 was the most expressed gene across experiments and the one that best discriminated between susceptible and resistant genotypes. These results are a valuable resource for future functional genomics studies to unravel the molecular mechanisms of C. sativus/P. melonis interaction.

Section: Clustering and Principal Component Analysissupporting

confidence: 93%

Section: Genetic Diversity Analysismentioning

confidence: 99%

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Correlation between cucumber genotype and resistance to damping-off disease caused by Phytophthora melonis

Golparvar

Biotechnology & Biotechnological Equipment

et al. 2019

Self Cite

“…Typical symptoms of the disease are root and root collar rot, stem lesions, foliar blight, fruit rot and plant death [3,4]. Although current control measures for P. melonis are based on the use of fungicides [5], identification of disease-resistant genotypes may be an effective and environmentally friendly strategy in modern crop production [6][7][8][9]. To date, analyses of the interaction between P. melonis and C. sativus have been limited on screening resistant genotypes to damping-off [1,6] and no cucumber genotype immune to P. melonis has been reported.…”

Section: Introductionmentioning

confidence: 99%

Novel Cucumis enzymes associated with host-specific disease resistance to Phytophthora melonis Katsura

Biotechnology & Biotechnological Equipment

Nasehi

et al. 2020

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The hemibiotrophic oomycetes are significant threats to a wide range of Cucurbitaceae species, causing substantial losses of plant productions. Particularly, Phytophthora melonis Katsura evokes severe symptoms, thus dramatically limiting the yield in cucumber. However, the information about cucumber-P. melonis interaction is still limited. This study explored the changes in the activities of phenylalanine ammonia-lyase (PAL), peroxidase (POX), catalase (CAT), superoxide dismutase (SOD) and polyphenol oxidase (PPO) in cucumber roots of two resistant genotypes (Soheil and Ramezz), one moderately resistant genotype (Baby) and three highly susceptible genotypes (Extrem, Mini 6-23 and Yalda), over the time courses of 7, 14 and 21 days after inoculation (DAI). The results indicated that the activities of defense-related enzymes differed between the resistant and highly susceptible genotypes. Although the defense-related enzymatic activities were elevated sharply in the resistant and moderately resistant genotypes after inoculation, no significant correlations were present between the activity trends of PPO, SOD and CAT and resistance characteristics. Moreover, no significant changes in enzyme activities were found in the control plants, non-inoculated plants of the six genotypes during the testing period. Altogether, the resistance of cucumber to P. melonis is related to POX and PAL activities, but does not show relationship with PPO, SOD and CAT activities. Studying the physiological metabolic pathways of POX and PAL appears to be an important direction in research to elucidate the resistance to P. melonis in cucumber genotypes.

“…Although current control measures forP. melonis are based on the use of fungicides (Lamichhane et al, 2017), identification of disease-resistant genotypes may be an effective strategy and environmentally friendly in modern crop production (Moghaddam et al, 2019;Hashemi et al, 2019). To date, analyses of the interaction between P. melonis and C. sativus have been limited on screening resistant genotypes to damping-off (Nazavari et al, 2016;Hashemi et al, 2019) and no cucumber genotype immune toP.…”

Section: -Introductionmentioning

confidence: 99%

Novel Cucumis Enzymes Associated with Host-Specific Disease Resistance to Phytophthora melonis

Nasehi

et al. 2020

Preprint

The hemibiotrophic oomycetes are significant threats to a wide range of Cucurbitaceae species, causing substantial losses of plant productions. Particularly, Phytophthora melonis evokes severe symptoms, thus dramatically limiting yield in cucumber. However, information about cucumber-P. melonis interaction is still limited. This study explored changes in the activities of phenylalanine ammonia-lyase (PAL), peroxidase (POX), catalase (CAT), superoxide dismutase (SOD), and polyphenol oxidase (PPO) in cucumber roots of two resistant genotypes (Soheil and Ramezz), one moderately resistant genotype (Baby) and three highly susceptible genotypes (Extrem, Mini 6-23 and Yalda), over the time courses of 7, 14 and 21 days after inoculation (DAI). The results indicated that the activities of defence-related enzymes differed between the resistant and highly susceptible genotypes. Although, the defense-related enzymatic activities were elevated sharply in the resistant and moderately resistant genotypes after inoculation, but no significant correlations were present between the activity trends of PPO, SOD and CAT and resistance characteristics. Moreover, no significant changes in enzyme activities were found in the control plants, non-inoculated plants of the six genotypes during the testing period. Altogether, the resistance of cucumber to P. melonis is related to POX and PAL activities, but does not show relationship with PPO, SOD and CAT activities. Studying the physiological metabolic pathways of POX and PAL appears to be an important direction in research to elucidate resistance to P. melonis in cucumber genotypes.