Teosinte alleles enhance nitrogen assimilation and seed protein in maize.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 42236942.
- Also identified by DOI 10.1038/s41586-026-10575-8.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
During maize (Zea mays L.) domestication, seed protein content sharply declined<sup>1,2</sup>. In plants, glutamine and asparagine levels are closely correlated with protein content<sup>3,4</sup>. Asparagine is synthesized from glutamine, a process catalysed by asparagine synthase<sup>5</sup>. Teosinte harbours a superior haplotype of asparagine synthase 4 (ASN4)<sup>2</sup>. Here, we report that teosinte also possesses a superior haplotype gene promoting glutamine synthesis. We identify and clone teosinte high protein 3 (THP3), which encodes glutamate-oxaloacetate transaminase 1 (GOT1), a key enzyme involved in nitrogen assimilation and carbon-nitrogen balance. The superior THP3-T allele, subjected to negative selection during domestication, has natural variations that boost both its expression and enzymatic activity. Overexpressing THP3-T, but not the modern THP3-B allele, significantly increases seed protein, representing altered carbon-nitrogen composition. Pyramiding THP3-T with THP9-T (the latter encoding asparagine synthase 4 (ASN4)) synergistically elevates both seed and whole-plant protein in elite hybrids while maintaining yield. Our findings demonstrate a powerful strategy for crop improvement by reintroducing beneficial rare alleles disfavoured during domestication from wild relatives.