A research team led by Yan Jianbing at Huazhong Agricultural University has identified a maize gene that can help improve yield, kernel protein content and nitrogen use efficiency, offering a potential tool for greener breeding of this staple food.

The study was published online in Nature Genetics on June 29. Using multi-omics analysis and a CUBIC maize population of 1,404 lines, the team mapped how primary metabolism is genetically regulated and identified 86 key metabolites in leaves and kernels.

The work led to the discovery of ZmAVT1A-1, a gene encoding an amino acid transporter on the vacuole membrane. Yan compared it to a "dispatch valve" that releases stored amino acids and helps deliver nitrogen to developing kernels.

"High yield and high protein are often seen as difficult to achieve together, but this valve can help maize gain both, " he said.

Experiments showed that knocking out the gene caused earlier leaf senescence and lower yield under low nitrogen conditions, while overexpression improved stay-green traits, yield per plant and kernel protein content. Yan said the gene works especially well under low nitrogen, matching the needs of green agriculture and China's carbon-reduction goals.

The team has developed ZmAVT1A-1 into a molecular marker and added it to a breeding chip containing more than 100 functional genes, enabling faster screening for lines that combine lodging resistance, suitable flowering time, high yield and high protein under lower nitrogen input.

The study identifies ZmAVT1A-1 as a green gene for maize yield and protein improvement. [Photo/new.hzau.edu.cn]