Gene discovery may lead to new soy varieties

 

 

Just months after the soy genome was sequenced, a Purdue University scientist has discovered a long-sought gene that controls the plant's main stem growth and could lead to the creation of new types of soy plants.

 

This new type will allow producers to incorporate desired characteristics into their local varieties.

 

Scientists used the research model plant Arabidopsis thaliana to discover the soy gene that controls whether the plant's stem continues to grow after flowering. The find is a significant key to diversifying the types of soy growers can produce all over the world.

 

"With the genomic resources and information available, we spent only six months pinpointing and confirming the candidate gene - the time it takes to grow one generation of soy," scientists said.

 

Soy plants generally fall into two categories: determinate plants whose main stem tips stop growing after flowering, and indeterminate plants that continue main stem growth after flowering.

 

In the US, indeterminate soy are grown in the northern states, while determinate are grown in the southern states, according to the researchers. A northern US grower who may want the characteristics found only in a type of determinate soy would not be able to successfully grow a determinant cultivar in the north.

 

The researchers were able compare the gene known to control Arabidopsis thaliana's stem growth pattern with the soy genome to identify four soy candidate genes. Those genes were then sequenced in a sample of different families of soy, including Glycine soja, a wild type of soy; Glycine max landraces, which were varieties developed through selection in Asia thousands of years ago; and elite cultivars, which are grown today in the US.

 

A single base-pair nucleotide mutation in the gene Dt1 was found to be the reason some plants are determinate. The researchers also tested the find by using an indeterminate soy Dt1 gene to change an Arabidopsis thaliana plant from determinate to indeterminate.

 

Meanwhile, researchers are set to find a gene that makes soy semi-determinate.

 

The National Science Foundation, Indiana Soybean Alliance and Purdue University funded this research.