Association of the molecular regulation of ear leaf senescence/stress response and photosynthesis/metabolism with heterosis at the reproductive stage in maize

• Published in: Scientific reports Vol. 6; no. 1; p. 29843
• Main Authors: Song, Yi, Zhang, Zhe, Tan, Xianjie, Jiang, Yufeng, Gao, Jiong, Lin, Li, Wang, Zhenhua, Ren, Jun, Wang, Xiaolei, Qin, Lanqiu, Cheng, Weidong, Qi, Ji, Kuai, Benke
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 20.07.2016; Nature Publishing Group
• Subjects: 38/39; 49/90; 631/114; 631/449; 631/553/2701; Abiotic stress; Agricultural production; Biodiversity; Biosynthesis; Corn; Crop yield; Developmental stages; Gene expression; Gene Expression Profiling - methods; Gene Expression Regulation, Plant; Gene Ontology; Genes, Plant - genetics; Humanities and Social Sciences; Hybrid Vigor - genetics; Hybridization, Genetic; Hybrids; Leaves; Metabolism; multidisciplinary; Phenotype; Photosynthesis; Photosynthesis - genetics; Physiology; Plant Breeding - methods; Plant Leaves - genetics; Plant Proteins - genetics; Plant Proteins - metabolism; Polymorphism; Reproduction - genetics; Rice; Science; Senescence; Time Factors; Zea mays - genetics; Zea mays - metabolism
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep29843

Maize exhibits a wide range of heterotic traits, but the molecular basis of heterosis at the reproductive stage has seldom been exploited. Leaf senescence is a degenerative process which affects crop yield and quality. In this study, we observed significantly delayed ear leaf senescence in the reciprocal hybrids of B73/Mo17 and Zheng58/Chang7-2 after silking and all the hybrids displayed larger leaf areas and higher stems with higher yields. Our time-course transcriptome analysis identified 2,826 differentially expressed genes (DEGs) between two parental lines (PP-DEGs) and 2,328 DEGs between parental lines and the hybrid (PH-DEGs) after silking. Notably, several senescence promoting genes ( ZmNYE1, ZmORE1, ZmWRKY53 and ZmPIFs ) exhibited underdominant expression patterns in the hybrid, whereas putative photosynthesis and carbon-fixation ( ZmPEPC )-associated, starch biosynthetic ( ZmAPS1, ZmAPL ), gibberellin biosynthetic genes ( ZmGA20OX , ZmGA3OX ) expressed overdominantly. We also identified 86 transcription factors from PH-DEGs, some of which were known to regulate senescence, stress and metabolic processes. Collectively, we demonstrate a molecular association of the regulations of both ear leaf senescence/stress response and photosynthesis/metabolism with heterosis at the late developmental stage. This finding not only extends our understanding to the molecular basis of maize heterosis but also provides basic information for molecular breeding.