Did Ancient Farmers Accidentally Hack Maize Crop Yield?
Source PublicationCell
Primary AuthorsGuo, Xia, Tang et al.
How did early farmers supercharge maize crop yield? During domestication, maize's harvest index—the proportion of photosynthates allocated directly to grain—boosted by a massive 81%, and scientists have just uncovered the exact genetic trick behind it. 🌽
Plants produce sugars through photosynthesis, but they must allocate those resources. Shifting energy toward leaves grows taller stalks, while directing it to seeds produces edible grain.
In genetic analyses, researchers identified a 9.1-kilobase DNA insertion termed HI1 that altered this balance. This genetic sequence acts as a long-distance enhancer, recruiting the transcription factor CONZ1 and an acetyltransferase called GCN5.
How DNA Loops Boost Maize Crop Yield
Together, these proteins bend the plant's DNA into a physical chromatin loop. This shape change switches on a key regulator gene called BRR1, which drives carbon and nitrogen transport directly into developing seeds.
Crucially, in molecular tests, this system maintains grain production even under nitrogen-limiting conditions. Data suggests targeting this regulatory module could help breeders develop high-yielding crops requiring significantly less synthetic fertiliser.