title: Expression and functional analysis of genes encoding cytokinin receptor-like histidine kinase in maize (Zea mays L.).
abstract: Cytokinin signaling is vital for plant growth and development which function via the two-component system (TCS). As one of the key component of TCS, transmembrane histidine kinases (HK) are encoded by a small gene family in plants. In this study, we focused on expression and functional analysis of cytokinin receptor-like HK genes (ZmHK) in maize. Firstly, bioinformatics analysis revealed that seven cloned ZmHK genes have different expression patterns during maize development. Secondly, ectopic expression by CaMV35S promoter in Arabidopsis further revealed that functional differentiation exists among these seven members. Among them, the ZmHK1a2-OX transgenic line has the lowest germination rate in the dark, ZmHK1-OX and ZmHK2a2-OX can delay leaf senescence, and seed size of ZmHK1-OX, ZmHK1a2-OX, ZmHK2-OX, ZmHK3b-OX and ZmHK2a2-OX was obviously reduced as compared to wild type. Additionally, ZmHK genes play opposite roles in shoot and root development; all ZmHK-OX transgenic lines display obvious shorter root length and reduced number of lateral roots, but enhanced shoot development compared with the wild type. Most notably, Arabidopsis response regulator ARR5 gene was up-regulated in ZmHK1-OX, ZmHK1a2-OX, ZmHK2-OX, ZmHK3b-OX and ZmHK2a2-OX as compared to wild type. Although the causal link between ZmHK genes and cytokinin signaling pathway is still an area to be further elucidated, these findings reflected that the diversification of ZmHK genes expression patterns and functions occurred in the course of maize evolution, indicating that some ZmHK genes might play different roles during maize development.
authors.affiliation: State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis Utilization (MOE), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Wang
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Chen
authors.forename: Baojian
authors.initials: B
authors.lastname: Guo
authors.forename: Muhammad Rezaul
authors.initials: MR
authors.lastname: Kabir
authors.forename: Yingyin
authors.initials: Y
authors.lastname: Yao
authors.forename: Huiru
authors.initials: H
authors.lastname: Peng
authors.forename: Chaojie
authors.initials: C
authors.lastname: Xie
authors.forename: Yirong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Qixin
authors.initials: Q
authors.lastname: Sun
authors.forename: Zhongfu
authors.initials: Z
authors.lastname: Ni
mesh_terms: D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D002734:Chlorophyll / Q000378:metabolism; D019295:Computational Biology; D003583:Cytokinins / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D018525:Germination; D000071677:Histidine Kinase; D059372:Nucleotide Motifs; D018515:Plant Leaves / Q000166:cytology / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D018517:Plant Roots / Q000166:cytology / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D018520:Plant Shoots / Q000166:cytology / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic; D011494:Protein Kinases / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D036226:Seedlings / Q000166:cytology / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D012639:Seeds / Q000166:cytology / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D015398:Signal Transduction; D003313:Zea mays / Q000166:cytology / Q000201:enzymology / Q000235:genetics* / Q000502:physiology
chemical_list: D003583:Cytokinins; D012333:RNA, Messenger; D002734:Chlorophyll; D011494:Protein Kinases; D000071677:Histidine Kinase