Table_1_Seed-Specific Overexpression of SPL12 and IPA1 Improves Seed Dormancy and Grain Size in Rice.docx

Pre-harvest sprouting (PHS) often results in reduced grain yield and quality and is a major problem in cereal production. Improved seed dormancy would inhibit PHS. Here we show that seed-specific overexpression of two SQUAMOSA-PROMOTER BINDING PROTEIN-LIKE (SPL) genes SPL12 and IPA1 enhances seed dormancy and inhibits PHS without noticeable effects on shoot architecture in rice. In addition, seed-specific overexpression of IPA1 also increases grain size and thus improves grain productivity. Furthermore, our results suggest that SPL12 enhances the seed dormancy through directly regulating many genes in the gibberellin (GA) pathway. This research provides an efficient method to suppress PHS and will facilitate breeding elite crop varieties.

收获前发芽（Pre-harvest sprouting，PHS）常会导致籽粒产量与品质下降，是谷类作物生产中的一大难题。增强种子休眠（seed dormancy）可抑制PHS。本研究证实，在水稻中种子特异性过表达2个SQUAMOSA启动子结合蛋白样（SQUAMOSA-PROMOTER BINDING PROTEIN-LIKE，SPL）基因SPL12与IPA1，可增强种子休眠并抑制PHS，且对水稻株型无显著不良影响。此外，种子特异性过表达IPA1还可增大籽粒尺寸，进而提升籽粒生产力。进一步研究表明，SPL12可通过直接调控赤霉素（gibberellin，GA）通路中的众多基因来增强种子休眠。本研究提供了一种抑制PHS的高效策略，将有助于选育优良作物品种。