title: microRNA-dependent gene regulatory networks in maize leaf senescence.
abstract: BACKGROUND
  Maize grain yield depends mainly on the photosynthetic efficiency of functional leaves, which is controlled by an array of gene networks and other factors, including environmental conditions. MicroRNAs (miRNAs) are small RNA molecules that play important roles in plant developmental regulation. A few senescence-associated miRNAs (SA-miRNAs) have been identified as important participants in regulating leaf senescence by modulating the expression levels of their target genes.
  
  
  RESULTS
  To elucidate miRNA roles in leaf senescence and their underlying molecular mechanisms in maize, a stay-green line, Yu87-1, and an early leaf senescence line, Early leaf senescence-1 (ELS-1), were selected as experimental materials for the differential expression of candidate miRNAs. Four small RNA libraries were constructed from ear leaves at 20 and 30 days after pollination and sequenced by Illumina deep sequencing technology. Altogether, 81 miRNAs were detected in both lines. Of these, 16 miRNAs of nine families were differentially expressed between ELS-1 andYu87-1. The phenotypic and chlorophyll content analyses of both lines identified these 16 differentially expressed miRNAs as candidate SA-miRNAs.
  
  
  CONCLUSIONS
  In this study, 16 candidate SA-miRNAs of ELS-1 were identified through small RNA deep sequencing technology. Degradome sequencing results indicated that these candidate SA-miRNAs may regulate leaf senescence through their target genes, mainly transcription factors, and potentially control chlorophyll degradation pathways. The results highlight the regulatory roles of miRNAs during leaf senescence in maize.
authors.affiliation: National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, 95 Wenhua Road, Zhengzhou, 450002, China.
authors.forename: Xiangyuan
authors.initials: X
authors.lastname: Wu
authors.affiliation: National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, 95 Wenhua Road, Zhengzhou, 450002, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Ding
authors.affiliation: National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, 95 Wenhua Road, Zhengzhou, 450002, China.
authors.forename: Chaonan
authors.initials: C
authors.lastname: Shi
authors.affiliation: National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, 95 Wenhua Road, Zhengzhou, 450002, China.
authors.forename: Yadong
authors.initials: Y
authors.lastname: Xue
authors.affiliation: National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, 95 Wenhua Road, Zhengzhou, 450002, China.
authors.forename: Zhanhui
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, 95 Wenhua Road, Zhengzhou, 450002, China. gtang1@mtu.edu.|Department of Biological Sciences, Michigan Technological University, Houghton, MI, 49931, USA. gtang1@mtu.edu.
authors.forename: Guiliang
authors.initials: G
authors.lastname: Tang
authors.affiliation: National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, 95 Wenhua Road, Zhengzhou, 450002, China. tangjihua1@163.com.|Hubei Collaborative Innovation Center for the Grain Industry, Yangtze University, Jingzhou, 434025, China. tangjihua1@163.com.
authors.forename: Jihua
authors.initials: J
authors.lastname: Tang
mesh_terms: D018506:Gene Expression Regulation, Plant; D053263:Gene Regulatory Networks; D035683:MicroRNAs / Q000502:physiology*; D018515:Plant Leaves / Q000378:metabolism* / Q000502:physiology; D018749:RNA, Plant / Q000502:physiology*; D013997:Time Factors; D003313:Zea mays / Q000235:genetics* / Q000502:physiology
chemical_list: D035683:MicroRNAs; D018749:RNA, Plant
keywords: Deep sequencing; Leaf senescence; Maize; Regulatory mechanism; microRNAs