Gene-edited Mustard

Table of Contents☰

About Gene-edited Mustard:

India’s most significant domestically-grown oilseed is rapeseed-mustard.
Issues with Mustard seeds
- Mustard seeds have high levels of glucosinolates, a group of sulphur and nitrogen-containing compounds contributing to the characteristic pungency of their oil and meal.
- Rapeseed meal is unpalatable to poultry and pigs, while having to be mixed with fodder grass and water for giving to cattle and buffaloes.
- Besides reducing their feed intake, high glucosinolates are also known to cause goiter (swelling of neck) and internal organ abnormalities in livestock.
- The dry seeds from the normal mustard (Brassica juncea) cultivated in India contain 120-130 parts per million (ppm or mg/kg) of glucosinolates. This is as against the sub-30 ppm levels in canola seeds.

A Gene Editing breakthrough

The Glucosinolates are synthesised in the leaves and pod walls of mustard plants.
Their translocation and accumulation in the seeds happens through the action of glucosinolate transporter or GTR genes.
There are 12 such genes under two distinct classes of GTR1 and GTR2 with six copies each.
Researchers edited 10 out of the 12 GTR genes in ‘Varuna’, a high-yielding Indian mustard variety.
For this, they used CRISPR/Cas9 – a gene-editing tool deploying an enzyme, which acts as a “molecular scissors” to cut the DNA at precise targeted locations of the gene, and then letting the natural DNA repair process to take over.
By doing this, their encoded proteins, responsible for transport of the glucosinolates to the seeds, were rendered non-functional.
By lowering the glucosinolate content to the same dry seed weight concentration, the scientists have bred mustard lines whose oil and meal match the standard of canola-quality rapeseed (Brassica napus) in terms of pungency.
The new GTR genes-edited mustard lines are transgene-free or non-genetically modified (GM).
They contain no foreign genes like those of the Bacillus thuringiensis bacteria in cotton or Bar-Barnase-Barstar (isolated from other soil bacteria) in the GM hybrid mustard (DMH-11).

Q1) What are Proteins?

Proteins are complex organic molecules composed of amino acids, which are the building blocks of life. They are essential components of all living organisms and play a wide variety of crucial roles in biological processes.

Source: Gene-edited mustard: Less pungent, more useful