NONSTOP GLUMES 1 regulates spikelet development in rice (Plant Cell)

Recently, several genes affecting rice architecture have been identified that may increase yields by increasing the number of grains formed, but as yet the genetic control of rice inflorescence architecture and organ identity is still being worked out. Zhuang et al. identified mutants of the NONSTOP GLUMES 1 (NSG1) gene (encoding a transcription factor) that affect spikelet development and shed light on the gene regulatory networks that specify floral and non-floral organs. Loss-of-function nsg1 mutants show abnormalities and partial conversion of the outer spikelet organs (glumes, lemmas, palea). Additional analysis showed ectopic expression of several organ identity genes in the mutant, including LEAFY HULL STERILE 1 (LHS1), DROOPING LEAF (DL), and MOSAIC FLORAL ORGANS 1 (MFO1). A greater understanding of the genetic and molecular mechanism of spikelet development could provide additional tools for increasing grain numbers and yields. (Summary by Mary Williams) Plant Cell 10.1105/tpc.19.00682