Despite the fact that corn is one of the world's most commonly-grown crops, it's still challenging to grow in northern regions, as it doesn't tolerate cold temperatures well. That could be about to change, though, as scientists have developed a hardier strain.
Led by Prof. David Stern, researchers at New York state's Boyce Thompson Institute started by looking at a naturally-occurring enzyme known as RuBisCO. Previous research already indicated that when levels of the substance were increased in plants, those plants grew larger and matured faster.
With that in mind, Stern's team created a variety of corn that produced higher-than-normal amounts of the enzyme. Alongside regular corn, those genetically-engineered plants were grown for three weeks at a temperature of 25 ºC (77 ºF), after which the temperature was lowered to 14 ºC (57 ºF) for two weeks, and then raised back to 25 degrees.
This was done in order to simulate the chilling that occurs when corn crops are planted in the springtime, and then subjected to a spell of cold weather. Ordinarily when this happens, the plants' growth is set back considerably. By the time they recover, it may be too late for them to reach maturity by the end of the growing season.
Such was not the case, however, with the RuBisCO-rich corn. Compared to the control plants, it exhibited higher rates of photosynthesis throughout the experiment. And after the chill, the engineered plants recovered much quicker – this was due to the fact that they experienced less damage to the molecules that carry out the photosynthesis process. As a result, the new strain grew taller than the control plants, and produced mature ears of corn faster.
The scientists are now working on making the engineered corn even hardier.
"The corn we developed isn’t yet completely optimized for chilling tolerance, so we are planning the next generation of modifications," says Stern. "For example, it would be very interesting to add a chilling-tolerant version of a protein called PPDK into the corn and see if it performs even better."
A paper on the research was recently published in Plant Biotechnology Journal.
Source: Boyce Thompson Institute
