This unique cabbage mutation could enhance crop yield. Here's everything to know

The journal, Nature Communications published a paper by the State Key Laboratory of Vegetable Biobreeding researchers of the Chinese Academy of Agricultural Sciences, Beijing. The research found that by deleting a very tiny part of the DNA of the genome of plants, the males of these plants can be made sterile. The deletion of this very small part of the genome's DNA of a wide array of plants like cauliflower, tomato, cabbage, rice, and broccoli can lead to significant outcomes. This simple deletion could lead to a great harvest of these crops. This becomes possible due to the process of heterosis.

Understanding the genes

There exist two long strands in the DNA molecule. Each of these strands is made of four compounds known as nucleotide bases. The compounds' bases are basically adenine, cytosine, guanine, and thymine. An adenine on one strand actually makes chemical bonds with thymine on the other strand, which are known as hydrogen bonds. Similarly, a cytosine on one strand makes hydrogen bonds with a guanine on the other strand.

The bonds between cytosine and guanine, and the bonds between adenine and thymine are actually responsible for holding the two strands of DNA together. A single adenine-thymine pair or a cytosine-guanine pair is known as a base pair (abbreviated as a bp for clarity).

If we talk about the cabbage plant (Brassica oleracea), its genome carries over 1.06 billion base pairs. These base pairs are organized in a total of 18 chromosomes. Every cell carries these in nine pairs of two each. Every pair of two chromosomes carries one chromosome coming from the pollen, while the other one comes from the egg. The DNA present in each chromosome pair carries a significantly identical sequence of bps.

A well-defined sequence of usually some thousand base pairs in the DNA molecule is the gene. Expressing a gene means that a segment of the base sequence on one of its two strands is actually copied to the sequence of the base in a related molecule, which is called RNA.

The master and working copies of a gene are the DNA and the RNA. The RNA is actually fitted into the ribosome. The base sequence of the RNA is used by the cellular machinery called ribosome to define the sequence in which the amino acids are associated together in order to form the protein encoded by the gene.

Basically, the DNA sequence of a gene specifies the amino acid sequence of the protein encoded along with defining the structure of the protein. The cell makes use of the RNA along with the ribosome in order to create this entity.

Observations made 4 decades ago

Over 44 years ago, it was found that a cabbage plant carried a natural mutation. Consequently, people found that the plant had actually lost the ability to produce pollen.

Initially, scientists could not figure out the gene that had been mutated in the plant. However, scientists named the altered gene as Ms-cd1.

The effect of the mutation was to make the plan male-sterile. It is important to note that there were no other defects found. Interestingly, the mutant plant's eggs could actually be fertilized by pollen from any normal plant. Additionally, these fertilized eggs would go on to create normal seeds.

In simpler words, all the mutant plants' seeds were actually a result of the eggs of the plants being fertilized by pollen coming from plants of other strains. This process is known as out-crossing. None of the seeds actually came an egg being fertilized by the pollen of the same strain, a process known as self-crossing.

The seeds that are out-crossed, also known as hybrid seeds, germinate in order to produce stronger plants as compared to the self-crossed seeds. This is due to the phenomenon known as hybrid vigor. The process is also known as heterosis.

What did the researchers find out?

According to the new study, the seeds from the male sterile plant incessantly brought forward bigger cabbages.

They discovered that the Ms-cdl mutation stood dominant. This meant that in case the mutant gene existed in only one chromosome of the pair, the plant would not be able to produce pollen, irrespective of whether the other chromosome contained a non-mutated gene.

Mutations are typically recessive. This means that The case of dominant mutations are comparatively rare.