BaffledExperts by Adam Norman

Red Menace: Stop the Ug99 Fungus Before Its Spores Bring Starvation | Magazine

I've been long interested in how we price little things like genetic codes. One day, a little-known wild grape is worthless. The next it's saving the world's vineyards. One day, a hardy little grain of wheat is in forgotten the back 40 of a campasino; the next, it's saving us all from famine.

In the US, stem rust was the bane of the Great Plains, which endured frequent epidemics throughout the 19th and early 20th centuries. One of the most disastrous episodes occurred in the middle of World War I, when P. graminis obliterated 200 million bushels of wheat — one-third of the nation’s annual consumption. Countless Midwestern families scrambled to survive on nutrient-poor corn mush. “There is and has been for the last six months very wide and extended suffering upon the part of the poor people of this country for want of food,” an Idaho senator declared in the spring of 1917, as the crisis reached its peak. Soon after, the spooked federal government ordered the eradication of barberry, the plant upon which P. graminis rests and reproduces when wheat is scarce. The epidemics abated, but they didn’t stop: A two-year outbreak in the mid-1950s, for example, caused $3 billion worth of damage to the Great Plains’ crops.

In the early 1940s, after the onset of World War II made it impossible to conduct philanthropic works in either Europe or China, the Rockefeller Foundation turned its attention to Mexico, where destitute campesinos suffered from chronic malnutrition. The foundation dispatched 30-year-old agronomist Norman Borlaug to Mexico in 1944 to lead a project aimed at ending the nation’s hunger. When Borlaug first arrived south of the border, Mexico was reeling from a three-year bout with stem rust, which had cut wheat production in half. Borlaug resolved to breed a variety of wheat that P. graminis could not kill. Thus began the Green Revolution, the lifesaving agricultural movement that would earn him the Nobel Peace Prize in 1970.

There was no high tech trick to Borlaug’s work, just countless hours of experimentation that he would later describe as “mind-warpingly tedious.” The Iowa native collected cereals from around the world, bred them with one another, and then took copious notes on the physical characteristics of the resulting crosses that fared well in Mexico’s fields. After many years of selecting and refining the top performers, he identified several genes capable of frustrating P. graminis. The most impressive was dubbed Stem Rust 31, or Sr31, a gene that several of Borlaug’s colleagues had bred into wheat from a rye chromosome.

Not only did Sr31 successfully fend off the pathogen, it also vastly improved grain yields. Farmers clambered to plant wheat that bore Sr31, which quickly became the world’s predominant rust-prevention gene. Developing nations in particular adopted the seeds, which they obtained from Borlaug’s International Maize and Wheat Improvement Center, or Cimmyt (pronounced “SIM-it”).

The creation of rust-resistant wheat was one of the cornerstone achievements of Borlaug’s Green Revolution, which produced multiple disease-proof, high-yielding crops capable of feeding once-hungry populations. By 1970, stem rust was no longer a threat to nations that relied on wheat as a dietary mainstay. It is impossible to calculate how many lives Sr31 and other disease-resistance genes saved, but hundreds of millions would be a fair guess. Finally able to feed their burgeoning populations, developing countries like India were able to grow and prosper beyond all expectations. Two generations of farmers and agronomists came of age never having witnessed a stem-rust infection in the wild, and P. graminis largely ceased to be of interest to anyone except Cold Warriors: The US and Soviet militaries spent years trying to weaponize the pathogen. (America developed a cluster bomb containing turkey feathers smeared with spores; the stockpile was eventually destroyed after President Nixon renounced the use of offensive bioweapons.)

via Red Menace: Stop the Ug99 Fungus Before Its Spores Bring Starvation | Magazine.