A cytokinin-activation enzyme-like gene improves grain yield under various field conditions in rice

• DOI: 10.1007/s11103-019-00952-5
• Publication Date: 2019-12-23T19:02:49Z
• Authors: Changgui Wang; Guokui Wang; Yang Gao; Guihua Lu; Jeffrey E. Habben; Guanfan Mao; Guangwu Chen; Jiantao Wang; Fan Yang; Xiaoqiang Zhao; Jing Zhang; Hua Mo; Pingping Qu; Junhua Liu; Thomas W. Greene
• Keywords: Gene Editing; 0301 basic medicine; 2. Zero hunger; Cytokinins; Nitrogen; Oryza; 15. Life on land; Plant Roots; 6. Clean water; Droughts; 03 medical and health sciences; Protein Domains; Gene Expression Regulation, Plant; Stress, Physiological; Seeds; CRISPR-Cas Systems; Edible Grain; Plant Proteins

CRISPR-edited variants at the 3'-end of OsLOGL5's coding sequence (CDS), significantly increased rice grain yield under well-watered, drought, normal nitrogen, and low nitrogen field conditions at multiple geographical locations. Cytokinins impact numerous aspects of plant growth and development. This study reports that constitutive ectopic overexpression of a rice cytokinin-activation enzyme-like gene, OsLOGL5, significantly reduced primary root growth, tiller number, and yield. Conversely, mutations at the 3'-end of OsLOGL5 CDS resulted in normal rice plant morphology but with increased grain yield under well-watered, drought, normal nitrogen, and low nitrogen field conditions at multiple geographical locations. Six gene edited variants (Edit A to F) were created and tested in the field. Edit-B and Edit-F plants increased, but Edit-D and Edit-E plants decreased, the panicle number per plant. All OsLOGL5-edited plants significantly increased seed setting rate, total grain numbers, full-filled grain numbers per panicle, and thousand seed weight under drought conditions, suggesting that OsLOGL5 is likely involved in the regulation of both seed development and grain filling processes. Our results indicate that the C-terminal end of OsLOGL5 protein plays an important role in regulating rice yield improvement under different abiotic stress conditions, and OsLOGL5 is important for rice yield enhancement and stability.