Agriculture

Agriculture has historically benefited directly from advances in genetic research. Crop productivity increases at a rate of 3% per year. About half of it is driven by enhanced genetics, with genetic gain rates expected to more than double with the implementation of emerging molecular technologies. For instance, more than 110 and 195 million tons of additional soybean and maize production from 1996 to 2013, was mainly attributed to positive yield effects of genetic technology^[1].

In late 2018, 'Revolutionizing Agriculture with Synthetic Biology' was held. In this meeting, they explored the potential of directed evolution, radical design of metabolic pathways, novel genetic circuitry and unique plant architectures to transform crop improvement^[2]. It provides guidance for the application of synthetic biology in agriculture.

Agricultural enzymes, sourced from microorganisms like fungi and bacteria, are catalyst that accelerates the chemical reaction that unblocks the nutrients present in the soil, and helps increase crop production, soil fertility, and food protection. The most commonly used enzymes in plant growth and soil fertility are phosphatases, dehydrogenases, and urease. Besides, carbohydrase, proteases, phytase, sulfatases, and amylases are very important in agriculture as well.

For instance, phosphatase enzymes, produced by bacteria, fungi and plant roots, can cleave a phosphate group from its substrates, transforming complex and sometime unavailable forms of organic P into assimilable phosphate, which is essential for energy transport, cellular structures and nucleic acids.

Arthropod crop pests are responsible for 20% of annual global crop losses, and this number is expected to increase under climate change as the ranges of many species are expected to expand. With the development of technology, synthetic biology and biotechnology are providing new options for pest control. Specific methods include [3]:

• New generations of insect-resistant crops

For example, three genes, Cry1Ac, Cry2A and Gna can be inserted into indica rice targeting rice leaf folder, Cnaphalocrocis medinalis, Scirpophaga incertulas, etc.

• RNA interference for pest control

For example, tomato plants expressing a dsRNA targeting a gene encoding a phenolic glucoside malonyltransferase, which detoxifies phenolic glycosides, shows complete resistance to the tobacco whitefly, Bemisia tabaci.

• Biomanufacturing pest control products

For example, the biosynthetic pyrethric acid has been widely used in pyrethrin insecticides.