title: Identification and characterization of CBL and CIPK gene families in canola (Brassica napus L.).
abstract: BACKGROUND
  Canola (Brassica napus L.) is one of the most important oil-producing crops in China and worldwide. The yield and quality of canola is frequently threatened by environmental stresses including drought, cold and high salinity. Calcium is a ubiquitous intracellular secondary messenger in plants. Calcineurin B-like proteins (CBLs) are Ca2+ sensors and regulate a group of Ser/Thr protein kinases called CBL-interacting protein kinases (CIPKs). Although the CBL-CIPK network has been demonstrated to play crucial roles in plant development and responses to various environmental stresses in Arabidopsis, little is known about their function in canola.
  
  
  RESULTS
  In the present study, we identified seven CBL and 23 CIPK genes from canola by database mining and cloning of cDNA sequences of six CBLs and 17 CIPKs. Phylogenetic analysis of CBL and CIPK gene families across a variety of species suggested genome duplication and diversification. The subcellular localization of three BnaCBLs and two BnaCIPKs were determined using green fluorescence protein (GFP) as the reporter. We also demonstrated interactions between six BnaCBLs and 17 BnaCIPKs using yeast two-hybrid assay, and a subset of interactions were further confirmed by bimolecular fluorescence complementation (BiFC). Furthermore, the expression levels of six selected BnaCBL and 12 BnaCIPK genes in response to salt, drought, cold, heat, ABA, methyl viologen (MV) and low potassium were examined by quantitative RT-PCR and these CBL or CIPK genes were found to respond to multiple stimuli, suggesting that the canola CBL-CIPK network may be a point of convergence for several different signaling pathways. We also performed a comparison of interaction patterns and expression profiles of CBL and CIPK in Arabidospsis, canola and rice, to examine the differences between orthologs, highlighting the importance of studying CBL-CIPK in canola as a prerequisite for improvement of this crop.
  
  
  CONCLUSIONS
  Our findings indicate that CBL and CIPK family members may form a dynamic complex to respond to different abiotic or hormone signaling. Our comparative analyses of the CBL-CIPK network between canola, Arabidopsis and rice highlight functional differences and the necessity to study CBL-CIPK gene functions in canola. Our data constitute a valuable resource for CBL and CPK genomics.
authors.forename: Hanfeng
authors.initials: H
authors.lastname: Zhang
authors.forename: Bo
authors.initials: B
authors.lastname: Yang
authors.forename: Wu-Zhen
authors.initials: WZ
authors.lastname: Liu
authors.forename: Hongwei
authors.initials: H
authors.lastname: Li
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.forename: Boya
authors.initials: B
authors.lastname: Wang
authors.forename: Min
authors.initials: M
authors.lastname: Deng
authors.forename: Wanwan
authors.initials: W
authors.lastname: Liang
authors.forename: Michael K
authors.initials: MK
authors.lastname: Deyholos
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas and, College of Life Sciences, Northwest A & F University, Yangling, Shaanxi 712100, China. jiangyq@nwafu.edu.cn.
authors.forename: Yuan-Qing
authors.initials: YQ
authors.lastname: Jiang
mesh_terms: D029688:Brassica napus / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000145:classification / Q000235:genetics / Q000378:metabolism
chemical_list: D002135:Calcium-Binding Proteins; D010940:Plant Proteins; D017346:Protein Serine-Threonine Kinases