Breakthrough in Breeding Low-Glucosinolate Mustard Seeds

• 22 Aug 2023

Recently, Indian scientists have developed the first ever low-pungent mustard that is pest and disease-resistant.

Key Points

• Utilizing Oilseeds to the Fullest: India's primary domestically-grown oilseed, rapeseed-mustard, contributes significantly to vegetable oil and meal production.
• While its oil is widely used, its meal, a protein-rich byproduct, finds application in livestock, poultry, and aqua feed.
• Rapeseed-Mustard's Role: Rapeseed-mustard accounts for 42.6% of India's vegetable oil production, second only to soybean at 19.2%. In meal production, it holds 30.3%, following soybean at 38.9%.
• Efforts to Improve Rapeseed-Mustard Quality: Scientists have been working to breed rapeseed-mustard lines with lower glucosinolate levels to match canola-quality rapeseed.
• Challenges Due to Glucosinolates: Mustard seeds contain glucosinolates, compounds that contribute to the oil and meal's pungency.
• High glucosinolate levels limit consumer acceptance of mustard oil and render rapeseed meal unpalatable to poultry and pigs, requiring mixing with fodder.
• Challenges in Large-scale Cultivation: One obstacle to large-scale cultivation of low-glucosinolate mustard lines is their vulnerability to pests and diseases. Glucosinolates serve as natural defenses for these plants.
• Gene Editing to the Rescue: Researchers have used CRISPR/Cas9 gene editing to modify 10 out of 12 glucosinolate transporter genes in Indian mustard (Varuna variety).
• This reduced glucosinolate content in seeds while maintaining high levels in other plant parts, aiding resistance against pests and diseases.
• Transgene-Free Innovation: The edited mustard lines are genome-edited (GE) and do not contain foreign genes.
• Less Cumbersome Regulatory Approval: Unlike genetically modified (GM) crops, GE lines are transgene-free and have no Cas9 protein, simplifying regulatory approval.
• Boosting Domestic Oilseed Production: India is a major importer of edible oils, spending billions annually. Enhancing domestic oilseed production, like low-glucosinolate mustard, can help reduce dependence on imports and save foreign exchange.