How Disease Lifestyle Affects Crop Disease Resistance Genes in Canola

Greg Howard
5th March, 2024

How Disease Lifestyle Affects Crop Disease Resistance Genes in Canola

Image Source: Natural Science News, 2024

Key Findings

  • Scientists at the John Innes Centre found genes in oilseed rape that help resist multiple fungal diseases
  • No single gene was found to resist all diseases; resistance varied with the fungus's infection strategy
  • A specific genomic deletion linked to broad disease resistance could aid future crop breeding
In the quest for hardier crops, scientists are on the lookout for ways to bolster plants against a suite of diseases, a challenge exacerbated by climate change and intensive agriculture. A recent study from the John Innes Centre has made significant strides in understanding how crops can resist multiple fungal diseases at once[1]. This research could be a game-changer for food security, as it explores the genetic underpinnings of disease resistance in oilseed rape (Brassica napus), a valuable crop for oil and animal feed. The problem at hand is that crops are vulnerable to a variety of fungal pathogens, each employing different strategies to infect plants. Traditional breeding methods focus on resistance to single diseases, but this approach is less effective against the diverse threats that crops face today. Scientists have identified a type of resistance known as quantitative disease resistance (QDR), which offers a broad-spectrum shield against multiple pathogens. Unlike resistance conferred by specific R genes, which pathogens can quickly overcome, QDR is a more durable form of defense[2]. The researchers at the John Innes Centre have utilized a technique called associative transcriptomics (AT) to identify genes that contribute to QDR in B. napus. AT combines gene expression data with genetic variation information to pinpoint candidate genes associated with particular traits—in this case, disease resistance. The study focused on resistance to four different fungal pathogens, each with a unique infection strategy: Alternaria brassicicola, Botrytis cinerea, Pyrenopeziza brassicae, and Verticillium longisporum. Interestingly, the study did not find any single gene locus that conferred resistance across all four pathogens. Instead, QDR was specific to the pathogen's lifestyle, with distinct genetic loci associated with resistance to each fungus. This suggests that plants may deploy different defense strategies depending on the type of threat they face, a concept supported by past research which found that plants need to tailor their defense mechanisms to the pathogen's mode of attack[3]. Moreover, the study identified a genomic deletion that was associated with resistance to V. longisporum and hinted at the possibility of broad-spectrum QDR. This deletion represents a potential target for breeding programs aiming to enhance disease resistance in crops. Such findings align with the ongoing efforts to develop genomic resources and use them in breeding superior cultivars with enhanced disease resistance[4]. Previous studies have also contributed to our understanding of plant-pathogen interactions. For instance, the identification of QDR loci in B. napus against the light leaf spot pathogen P. brassicae[2], and the discovery of a MATE gene in wheat that regulates defense against the sharp eyespot disease[5]. These studies emphasize the complexity of plant defense and the potential for genetic improvement to bolster crop resilience. The John Innes Centre's research represents the first time AT has been applied to multiple pathosystems simultaneously to identify genetic loci involved in broad-spectrum QDR. This approach has uncovered candidate loci for QDR that do not inadvertently increase susceptibility to other pathogens. These loci are promising targets for breeding programs that aim to produce crop varieties with robust, multi-pathogen resistance. In summary, the study provides new insights into the genetic basis of QDR in B. napus and offers valuable information for future crop improvement strategies. By identifying specific genetic loci associated with resistance to a range of fungal pathogens, the research paves the way for the development of B. napus cultivars that can withstand multiple diseases, an essential step towards ensuring food security in an increasingly unpredictable agricultural landscape.

AgricultureGeneticsPlant Science

References

Main Study

1) Pathogen lifestyle determines host genetic signature of quantitative disease resistance loci in oilseed rape (Brassica napus).

Published 2nd March, 2024

https://doi.org/10.1007/s00122-024-04569-1

Related Studies

2) Novel gene loci associated with susceptibility or cryptic quantitative resistance to Pyrenopeziza brassicae in Brassica napus.

https://doi.org/10.1007/s00122-023-04243-y

3) Molecular plant immunity against biotrophic, hemibiotrophic, and necrotrophic fungi.

https://doi.org/10.1042/EBC20210073

4) Key Advances in the New Era of Genomics-Assisted Disease Resistance Improvement of Brassica Species.

https://doi.org/10.1094/PHYTO-08-22-0289-FI

5) The Pathogen-Induced MATE Gene TaPIMA1 Is Required for Defense Responses to Rhizoctonia cerealis in Wheat.

https://doi.org/10.3390/ijms23063377


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