New plant research leads to the discovery of a gene that significantly increases seed yield in maize

Dirk Inzé and Hilde Nelissen

Researchers from VIB-UGent have discovered a gene that significantly increases plant growth and seed yield in maize. Research into crop yield is crucial because of the increasing incidence of extreme weather conditions affecting agriculture. The results from laboratory research were confirmed during two-year field trials conducted in Belgium and the United States showing that this gene can increase seed yield in maize hybrids by 10 to 15%. The results of the greenhouse and field trials are published in the scientific journal Nature Communications.

Nowadays, there is no crop in the world cultivated more than maize. Worldwide, 180 million hectares of maize are planted every year with a production of approximately 1 billion tons a year. Maize cultivation in Belgium has also made considerable advances over the last few decades, making maize, with a surface area of 240,000 hectares, one of the most commonly grown crops. Maize is primarily cultivated as animal feed, but also for human consumption and, to a lesser extent, as a source of biofuels. Research into new maize varieties is of great importance to maintain sufficient maize production in rising temperatures due to global warming. By selecting growth-enhancing genes, breeders can develop improved agricultural crops, which offer harvest security even in a changing climate.

PLA1 improves crop yield in maize 

Standard maize cobs (left) and PLA1 maize cobs (right)

VIB-UGent scientists, headed by Prof. Dirk Inzé and Dr. Hilde Nelissen, are conducting research into the molecular mechanisms behind leaf growth in maize. Leaf development is a blueprint for the plant’s growth processes. Indeed, knowing how leaves grow provides a great deal of information about the growth of the plant as a whole. The researchers discovered a gene in maize, named PLA1, which significantly increases plant growth and the size of plant organs such as the leaves, but also the cob. Dirk Inzé (VIB-UGent) says: “We have succeeded in significantly boosting biomass and seed production by increasing PLA1 expression in the plant, which leads to a yield increase of 10 to 15% on the same agricultural area.”

Scientific research at the cell level demonstrated that PLA1 extends the duration of plant growth. “Plants with the PLA1 trait therefore grow longer, meaning they become bigger and produce more seeds, which can be a benefit to farmers”, says Hilde Nelissen (VIB-UGent). Multi-seasonal field experiments, both in Belgium and the United States, have shown that PLA1 increases biomass and seed yield in maize inbred lines and hybrids.
The field trials in Belgium were conducted in cooperation with ILVO [Institute for Agricultural and Fisheries Research]. This is part of the strategic alliances between VIB and ILVO to translate basic mechanisms into applications for agriculture.

“Using the maize leaf as a research model, we have already made substantial contributions to unravel the plant’s growth processes”, says Dirk Inzé. “This work is a fantastic demonstration that basic research on how leaves grow gives unprecedented insights into how to improve the yield of important crops such a maize.”

More knowledge enhances strategies for maintaining crop yield in a changing climate

In the greenhouse, the researchers discovered that PLA1 plays a role in how plants cope with drought stress. The growth-enhancing PLA1 trait appeared to partly compensate for the growth reduction that normally occurs as a result of long periods of water shortage. These findings thus also offer a perspective for developing agricultural crops that guarantee stable yields even when the weather conditions are less favorable. In this way, new varieties of crops can help cope with the effects of climate change.

Further research is now focusing on finding out the molecular mechanisms that lie at the basis of the increased yield.