Gene 'figurehead' - key to increasing crop productivity

(With the population size of 9.5 billion people in 2050, humanity faces the challenge of providing food to serve a large number of people, while the amount Water, fertilizer and farmland are unchanged.

Researchers at Cornell University (USA) have taken a step forward in meeting this requirement, by discovering a gene that can produce new major crop varieties with a half-productivity increase. .

This gene, called 'Scarecrow' , was first discovered to regulate a leaf structure - called the Kranz anatomy, which increases photosynthetic efficiency. Photosynthetic plants in one of two ways: one is C3, this is less effective but is found in most plants; the second is C4, which is more efficient and found in grasses, corn, sorghum (sorghum) and sugarcane, which are well adapted to drought, strong light or poor nitrogen soil. .

Researchers have worked hard to find the fundamental genetic problems of Kranz's anatomical structure, from which they can be applied to the cultivation of C3 plants.

The research results 'gave a clue as to how the entire core of Kranz surgery was adjusted , ' said Professor Robert Turgeon from the College of Science and Arts (USA). 'There are still a lot of issues to study, but the door has been opened and you will see people pursuing this Scarecrow gene research'. The prospect of switching C4 plants' photosynthetic mechanism to C3 trees is coming to the fore when it has been invested globally for several decades.

If C4 photosynthesis can be applied to C3 plants through genetic engineering, farmers can grow wheat and rice in hotter and drier weather conditions and use less fertilizer. which can increase productivity by half.

By examining the evolutionary and anatomical problem of plants, researcher Slewinski realized that cells encircling C4 leaf veins are similar to endoderm cells surrounding vascular tissues in the trunk and roots.

Professor Slewinski argues that if the C4 leaves have the same endoderm with the stem and roots, the genes that control these types of cells may be the same. Slewinski considers experimenting with corn lines containing mutant Scarecrow genes - the gene that controls endoderm cells in the roots. When the researchers planted the plant, they found problems in the roots, then they checked the abnormalities in the vascular bundle. The researchers found that leaves containing the mutant Scarecrow gene contained abnormal vascular bundles and veins.

All plants contain an enzyme called RuBisCo , which helps plants absorb carbon dioxide, the first step to creating starch. However, in C3 and RuBisCo plants, there is also oxidation function, thus reducing photosynthetic efficiency by 30 to 40%. In plant C4, the process of fixing carbon dioxide takes place in two stages. The first stage occurs in chlorophyll cells, and the product of this stage is transferred to the vascular bundle for the RuBisCo period. The RuBisco phase is very effective because in the cells the vascular bundle contains less oxygen but more carbon dioxide. This helps eliminate oxidation, so plants are more productive.