A retrotransposon insertion in the <i>Mao1</i> promoter results in erect pubescence and higher yield in soybean

Abstract

Adaptive changes in crops contribute to the diversity of agronomic traits, which directly or indirectly affect yield. The change of pubescence form from appressed to erect is a notable feature during soybean domestication. However, the biological significance and regulatory mechanism underlying this transformation remain largely unknown. Here, we identified a major-effect locus, <i>PUBESCENCE FORM 1</i> (<i>PF1</i>), the upstream region of <i>Mao1</i>, that regulates pubescence form in soybean. The insertion of a Ty3/<i>Gypsy</i> retrotransposon in <i>PF1</i> can recruit the transcription factor GAGA-binding protein to a GA-rich region, which up-regulates <i>Mao1</i> expression, underpinning soybean pubescence evolution. Interestingly, the proportion of improved cultivars with erect pubescence increases gradually with increasing latitude, and erect-pubescence cultivars have a higher yield possibly through a higher photosynthetic rate and photosynthetic stability. These findings open an avenue for molecular breeding through either natural introgression or genome editing toward yield improvement and productivity.