Heterosis-related genes under different planting densities in maize

Ma, Juan
Zhang, Dengfeng
Cao, Yanyong
Wang, Lifeng
Li, Jingjing
Lubberstedt, Thomas
Wang, Tianyu
Li, Yu
Li, Huiyong
Journal Title
Journal ISSN
Volume Title
Research Projects
Organizational Units
Organizational Unit
Journal Issue

Heterosis and increasing planting density have contributed to improving maize grain yield (GY) for several decades. As planting densities increase, the GY per plot also increases whereas the contribution of heterosis to GY decreases. There are trade-offs between heterosis and planting density, and the transcriptional characterization of heterosis may explain the mechanism involved. In this study, 48 transcriptome libraries were sequenced from four inbred Chinese maize lines and their F1 hybrids. They were planted at densities of 45,000 plants/ha and 67,500 plants/ha. Maternal-effect differentially expressed genes (DEGs) played important roles in processes related to photosynthesis and carbohydrate biosynthesis and metabolism. Paternal-effect DEGs participated in abiotic/biotic stress response and plant hormone production under high planting density. Weighted gene co-expression network analysis revealed that high planting-density induced heterosis-related genes regulating abiotic/biotic stress response, plant hormone biosynthesis, and ubiquitin-mediated proteolysis but repressed other genes regulating energy formation. Under high planting density, maternal genes were mainly enriched in the photosynthesis reaction center, while paternal genes were mostly concentrated in the peripheral antenna system. Four important genes were identified in maize heterosis and high planting density, all with functions in photosynthesis, starch biosynthesis, auxin metabolism, gene silencing, and RNA interference.


This is a mansucript of an article published as Ma, Juan, Dengfeng Zhang, Yanyong Cao, Lifeng Wang, Jingjing Li, Thomas Lübberstedt, Tianyu Wang, Yu Li, and Huiyong Li. "Heterosis-related genes under different planting densities in maize (Zea mays L.)." Journal of Experimental Botany (2018). doi: 10.1093/jxb/ery282. Posted with permission.

differentially expressed gene, heterosis, maize, planting density, transcriptome, weighted gene co-expression network analysis