Gene-Edited Mustard

Gene-Edited Mustard

This article covers “Daily Current Affairs” and the topic details “Gene-Edited Mustard”. The topic “Gene-Edited Mustard” has relevance in the Agriculture section of the UPSC CSE exam.

For Prelims:

About Rapeseed-Mustard?

About Canola Mustard?

For Mains:

GS 3: Agriculture

Differences Between GM (Gene Modified) and GE (Gene Edited) Crops?

Significance of the New Breakthrough?

Why in the news:

Utilizing CRISPR/Cas9 gene editing, Indian researchers have successfully engineered the world’s First low-pungency mustard variety, boasting resistance against pests and diseases. This innovation stands out for its non-GM and transgene-free nature.

Importance of Rapeseed-Mustard in India

Rapeseed-mustard holds a paramount position among domestically cultivated oilseeds in India. It commands a substantial share of 42.6% in vegetable oil production, surpassing soybean’s 19.2%. Additionally, it constitutes 30.3% of meal production, second only to soybean (38%) . The residual cake, a byproduct of oil extraction, serves as a protein-rich component in livestock, poultry, and aqua feed.

Challenges Associated with Conventional Rapeseed-Mustard

  • Elevated Glucosinolate Levels: Mustard seeds contain considerable amounts of glucosinolates, sulfur and nitrogen compounds contributing to the characteristic pungency of their oil and meal. However, this pungency poses a barrier to consumer acceptance, particularly among those who prefer milder flavors.
  • Residue Cake Issue: The residue cake derived from rapeseed meal presents challenges. It is unsuitable for poultry and pigs, necessitating a mixture with fodder for cattle and buffaloes. Furthermore, the high glucosinolate content in the meal can lead to health issues in livestock, including goiter and organ abnormalities.


Research Efforts towards Canola-Quality Mustard

Extensive research spanning two decades has been directed towards developing rapeseed-mustard varieties with Canola-quality attributes. This research has been spearheaded by scientists from Delhi University’s Centre for Genetic Manipulation of Crop Plants (CGMCP) and the Indian Council of Agricultural Research (ICAR).

Distinctive Traits of Canola-Quality Mustard

  • Reduced Glucosinolate Levels: Normal mustard seeds (Brassica juncea) cultivated in India typically contain glucosinolate levels of 120-130 parts per million (ppm or mg/kg) in dry seeds. In contrast, canola seeds exhibit markedly lower levels, measuring below 30 ppm.
  • Mitigated Pungency: By achieving lowered glucosinolate content, scientists have succeeded in creating mustard lines with oil and meal qualities akin to those of standard canola-quality rapeseed.


Challenges in Scaling Canola-Quality Mustard Cultivation

  • Limited Large-Scale Cultivation: Despite the advantages of reduced glucosinolate levels, the widespread cultivation of canola-quality mustard has not been realized on a significant scale.
  • Susceptibility to Pests and Diseases: The altered glucosinolate levels render canola-quality mustard susceptible to pests and diseases, undermining its natural defenses.


Breakthrough in Gene-Edited Mustard

  • Glucosinolates are synthesized within the foliage and pod walls of mustard plants. The subsequent transfer and accumulation of these compounds within the seeds are performed by the activity of genes known as glucosinolate transporters (GTR).
  • These GTR genes are classified into two categories: GTR1 and GTR2, encompassing a total of 12 genes with six copies each. In a pioneering feat, researchers have meticulously edited 10 out of the 12 GTR genes within ‘Varuna,’ a high-yielding Indian mustard variant.
  • To achieve this, the researchers harnessed the power of CRISPR/Cas9 technology, a gene-editing tool that employs an enzyme functioning as molecular scissors. This enzyme selectively cleaves the DNA at precisely targeted gene locations. Subsequently, the natural DNA repair mechanisms step in to complete the process.
  • By utilizing CRISPR/Cas9 editing, the researchers have introduced mutations and modifications to the nucleotide sequence, the fundamental building blocks of DNA, within the 10 identified GTR genes. As a consequence of these modifications, the proteins encoded by these genes, which are responsible for transporting glucosinolates to the seeds, have been rendered inactive.


Advantages of Gene-Edited Mustard

Optimal Glucosinolate Balance: 

  • The seeds of the Varuna mustard variety resulting from targeted gene editing exhibited a glucosinolate content significantly below the 30-ppm threshold required for canola-quality standards. This achievement ensures a well-calibrated glucosinolate level in the seeds.
  • Furthermore, the remaining parts of the plant, notably the leaves and pod walls that enfold the seeds, showcased a notable increase in glucosinolate accumulation.


Enhanced Resistance Against Pests and Diseases

  • The Varuna mustard lines, edited to have low-seed and high-leaf glucosinolate content through GTR manipulation, underwent rigorous testing against formidable adversaries. These adversaries included the virulent fungal pathogen Sclerotinia sclerotiorum and the pest Spodoptera litura.
  • The edited lines remarkably demonstrated a defense response that either equaled or surpassed that of the wild-type mustard. This enhanced defense mechanism could be attributed to the augmented glucosinolate concentration within the leaves and pod walls.


Differences Between GM (Gene Modified) and GE (Gene Edited) Crops

Transgene-Free Nature of GE Mustard

  • The newly developed mustard lines achieved through GTR gene manipulation are considered transgene-free or non-genetically modified (GM).
  • Unlike genetically modified (GM) crops, these lines do not contain foreign genes, contrasting with GM examples like Bacillus thuringiensis genes in cotton or Bar-Barnase-Barstar genes in GM hybrid mustard (DMH-11) developed by CGMCP scientists.
  • The mustard lines, characterized by higher glucosinolate content in leaves compared to seeds, fall under the genome-edited (GE) category, distinct from GM or transgenic plants.
  • Initial genetic modifications in the first-generation plants involve the Cas9 enzyme from Streptococcus pyogenes bacteria. However, this Cas9 protein is not present in subsequent generations, resulting in final GE lines devoid of it and transgenes.


Regulatory Shifts Favoring GE Plants

  • Current regulations in India impose strict “environmental release” rules on GM crops, covering commercial cultivation, field trials, and seed production.
  • Clearance for such releases requires approval from the Genetic Engineering Appraisal Committee (GEAC) under the Ministry of Environment, Forest, and Climate Change (MoEFCC).
  • Recently, the MoEFCC introduced an exemption for GE plants lacking introduced foreign DNA from the need for GEAC approval in open field trials leading to commercial release.
  • The responsibility for clearance has now shifted to the Institutional Biosafety Committee (IBSC), consisting of scientists from institutions involved in GE crop development and the Department of Biotechnology (DBT).


Significance of the New Breakthrough:

Reducing Edible Oil Imports Dependency

  • India heavily relies on edible oil imports, with imports valued at $20.84 billion (Rs 167,270 crore) in the fiscal year ending March 2023. These imports cover over 60% of the country’s edible oil consumption.
  • The innovative GM hybrid mustard and GE low-seed high-leaf glucosinolate lines are notable advancements in plant breeding by Indian scientists. These breakthroughs have the potential to decrease India’s dependence on imported vegetable oils.


Enhancing Crop Yield and Product Quality

  • Mustard and soybean are crucial oilseed crops in India, cultivated on 9 million and 12.5 million hectares annually, respectively.
  • Mustard has an edge due to its higher oil content (38% compared to soybean’s 18%). It serves as a source of both dietary fat for humans and protein for animals.
  • To counter the economic strain caused by imports, there’s an urgent need to boost domestic oilseed production. This requires focused breeding to increase crop yields, enhance resistance to pests and diseases, and elevate product quality.


In Conclusion

The remarkable achievement of Gene-Edited Mustard, pioneered by Indian scientists, holds profound significance in the realm of Indian agriculture. This breakthrough has the potential to reduce India’s reliance on imported edible oils, increase crop yields, and positively impact product quality increasing the resilience of Indian agriculture.


plutus ias current affairs eng med 22th August 2023

Q.1 Consider the following statements regarding Gene Edited (GE) Crops:

  1. GE crops essentially contain foreign genes.
  2. GE crops with Foreign genes require approval from the Institutional Biosafety Committee (IBSC).

Which of the statements given above is/are correct? 

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 nor 2


Q.2 The term “Canola” is related to which of the following crops?

(a) Cotton

(b) Soybean

(c) Sunflower

(d) Mustard


Q.3 “Discuss the Significance and Advancements in Rapeseed-Mustard Cultivation in India, with a Focus on Canola-Quality Varieties.

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