A large transposon insertion in the stiff1 promoter increases stalk strength in maize (Plant Cell)

We all know the importance of staying upright, especially for our grass crops. Here, Zhang et al. identified a gene underlying a large-effect quantitative trait locus that confers stiff stalks, so prevents lodging. They show that the stiff-stock allele carries a large transposon that strongly represses expression of the encoded F-box protein. Lines carrying this insertion show increased cell wall thickness in sclerenchyma cells from the rind region and stalk vascular bundles. Conversely, when they overexpressed the F-box protein the plants had thin, soft, lodging-prone stalks. Using genome editing, the authors introduced a frame-shift mutation with a premature stop codon, phenocopying the effect of the transposon insertion, which provides a new resource for breeding lodging-resistant maize. (Summary by Mary Williams) Plant Cell 10.1105/tpc.19.00486