Putative role of IAA during the early response of Brassica napus L. to Plasmodiophora brassicae

2016 ◽  
Vol 145 (3) ◽  
pp. 601-613 ◽  
Author(s):  
Li Xu ◽  
Li Ren ◽  
Kunrong Chen ◽  
Fan Liu ◽  
Xiaoping Fang
Plant Disease ◽  
2021 ◽  
Author(s):  
Homa Askarian ◽  
Alireza Akhavan ◽  
Leonardo Galindo González ◽  
Sheau-Fang Hwang ◽  
Stephen Ernest Strelkov

Clubroot, caused by Plasmodiophora brassicae Woronin, is a significant threat to the canola (Brassica napus L.) industry in Canada. Clubroot resistance has been overcome in more than 200 fields since 2013, representing one of the biggest challenges to sustainable canola production. The genetic structure of 36 single-spore isolates derived from 12 field isolates of P. brassicae collected before and after the introduction of clubroot resistant (CR) canola cultivars (2005-2014) was evaluated by simple sequence repeat (SSR) marker analysis. Polymorphisms were detected in 32 loci with the identification of 93 distinct alleles. A low level of genetic diversity was found among the single-spore isolates. Haploid linkage disequilibrium and number of migrants suggested that recombination and migration were rare or almost absent in the tested P. brassicae population. A relatively clear relationship was found between the genetic structure and virulence phenotypes of the pathogen as defined on the differential hosts of Somé et al., Williams and the Canadian Clubroot Differential (CCD) set. Although genetic variability within each pathotype group, as classified on each differential system, was low, significant genetic differentiation was observed among the pathotypes. The highest correlation between genetic structure and virulence was found among matrices produced with genetic data and the hosts of the CCD set, with a threshold index of disease of 50% to distinguish susceptible from resistant reactions. Genetically homogeneous single-spore isolates provided a more complete and clearer picture of the population genetic structure of P. brassicae, and the results suggest some promise for the development of pathotype-specific primers.


Plant Disease ◽  
2021 ◽  
Vol 105 (1) ◽  
pp. 43-52 ◽  
Author(s):  
Homa Askarian ◽  
Alireza Akhavan ◽  
Victor P. Manolii ◽  
Tiesen Cao ◽  
Sheau-Fang Hwang ◽  
...  

Clubroot, caused by Plasmodiophora brassicae Woronin, is an important disease of canola (Brassica napus L.) that is managed mainly by planting clubroot-resistant (CR) cultivars. Field isolates of P. brassicae can be heterogeneous mixtures of various pathotypes, making assessments of the genetics of host–pathogen interactions challenging. Thirty-four single-spore isolates were obtained from nine field isolates of the pathogen collected from CR canola cultivars. The virulence patterns of the single-spore and field isolates were assessed on the 13 host genotypes of the Canadian Clubroot Differential (CCD) set, which includes the differentials of Williams and Somé et al. Indices of disease (IDs) severity of 25, 33, and 50% (±95% confidence interval) were compared as potential thresholds to distinguish between resistant and susceptible reactions, with an ID of 50% giving the most consistent responses for pathotype classification purposes. With this threshold, 13 pathotypes could be distinguished based on the CCD system, 7 on the differentials of Williams, and 3 on the hosts of Somé et al. The highest correlations were observed among virulence matrices generated using the three threshold IDs on the CCD set. Genetically homogeneous single-spore isolates gave a clearer profile of the P. brassicae pathotype structure. Novel pathotypes, not reported in Canada previously, were identified among the isolates. This large collection of single-spore isolates can serve as a reference in screening and breeding for clubroot resistance.


2015 ◽  
Vol 402 (1-2) ◽  
pp. 63-76 ◽  
Author(s):  
Kai Eggert ◽  
Nicolaus von Wirén

1996 ◽  
Vol 45 (3) ◽  
pp. 432-439 ◽  
Author(s):  
A. SOME ◽  
M. J. MANZANARES ◽  
F. LAURENS ◽  
F. BARON ◽  
G. THOMAS ◽  
...  

1998 ◽  
Vol 17 (1) ◽  
pp. 19-23 ◽  
Author(s):  
J. A. Wilmer ◽  
S. R. Abrams ◽  
J. P. F. G. Helsper ◽  
L. H. W. van der Plas

2020 ◽  
Vol 33 (1) ◽  
pp. 13-20
Author(s):  
Muhammad Awais Ghani ◽  
Muhammad Mehran Abbas ◽  
Basharat Ali ◽  
Khurram Ziaf ◽  
Muhammad Azam ◽  
...  

Tri-genomic Brassica napus L.wasdeveloped by the cross between Brassica napusand Brassica nigra. The crop is animportant source of vegetable seed oil in Pakistan,after cotton. The low oilseed rape yield is attributed to high temperature in the production zones. Interspecific hybridization using these two speciescan be helpful to produce heat resistant hybrids. On the other hand, it has been found that foliar application of different plant growth regulators can be used to reduce the heat stress in Brassica. The objectiveof this studywas to test the response of three different tri-genomic hybrids to high temperature stressat seedling stage. Seedlings were foliar sprayed with 0.13 mM salicylic acid (SA) prior to exposure tohigh temperatureat two true leaf stage. The plants were harvested after 30 days of sowing for growth and biochemical analysis. Plants ofV38 showed the highest values for all morphological traits and biochemical activities among the threehybrids. In general, plants exposed to the temperature stress exhibited a significant decline in growth, chlorophyll content and enzyme activity.Foliar application of SA significantly improved leaf and root biomass under heat stress.Further, antioxidativeenzyme activities significantly increased in response to SA either compared to control or to plants exposed to temperature stress.It is concluded thatapplication of salicylic acid elevated activity of antioxidative enzymes and was helpful in mitigating the detrimental effects of high temperature inoil seed rape.


Author(s):  
Mahdi Khozaei ◽  
Shiva Boroumand Jazi

Oilseed plant, Brassica napus L. seedlings grown in hydroponic condition with different concentrations of Pb were treated with salicylic acid (SA) to investigate the role of exogenous salicylic acid in alleviating lead toxicity on biochemical and physiological activities of the plant. The results showed that application of different concentrations of Pb increased soluble sugars and reduced carbohydrate levels significantly in roots and shoots of the plants. The stress induced by application of Pb triggered significant inhibitory effects on growth and chlorophyll synthesis induced on the production of protein and proline and enhanced the levels of antioxidant activity. Salicylic acid (SA) treated plants showed alleviation increasing total dry mass, leaf area, shoot and root length as well as leaf total chlorophyll content in responses to Pb stress. Results revealed the importance of salicylic acid (SA) activity in enabling plants to reduce the soluble sugars and increase of insoluble sugar in heavy -metal-stressed plants. The content of proline and proteins were also reduced in plants were treated with salicylic acid. Our data provide evidence that salicylic acid treatment decreased the activity of antioxidant enzymes in plants were exposed to different levels of Pb.


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