title: Molecular cloning and functional characterization of a novel apple MdCIPK6L gene reveals its involvement in multiple abiotic stress tolerance in transgenic plants.
abstract: CBL-interacting protein kinases (CIPKs) are involved in many aspects of plant responses to abiotic stresses. However, their functions are poorly understood in fruit trees. In this study, a salt-induced MdCIPK6L gene was isolated from apple. Its expression was positively induced by abiotic stresses, stress-related hormones and exogenous Ca(2+). MdCIPK6L was not homologous to AtSOS2, however, its ectopic expression functionally complemented Arabidopsis                         sos2 mutant. Furthermore, yeast two-hybrid assay showed that MdCIPK6L protein interacted with AtSOS3, indicating that it functions in salt tolerance partially like AtSOS2 through SOS pathway. As a result, the overexpression of both MdCIPK6L and MdCIPK6LT175D remarkably enhanced the tolerance to salt, osmotic/drought and chilling stresses, but did not affect root growth, in transgenic Arabidopsis and apple. Also, T-to-D mutation to MdCIPK6L at Thr175 did not affect its function. These differences between MdCIPK6L and other CIPKs, especially CIPK6s, indicate that MdCIPK6L encodes a novel CIPK in apple. Finally, MdCIPK6L overexpression also conferred tolerance to salt, drought and chilling stresses in transgenic tomatoes. Therefore, MdCIPK6L functions in stress tolerance crossing the species barriers, and is supposed to be a potential candidate gene to improve stress tolerance by genetic manipulation in apple and other crops.
authors.affiliation: State Key Laboratory of Crop Biology, National Research Center for Apple Engineering and Technology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong 271018, China.
authors.forename: Rong-Kai
authors.initials: RK
authors.lastname: Wang
authors.forename: Ling-Li
authors.initials: LL
authors.lastname: Li
authors.forename: Zhong-Hui
authors.initials: ZH
authors.lastname: Cao
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhao
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.forename: Ling-Yun
authors.initials: LY
authors.lastname: Zhang
authors.forename: Yu-Jin
authors.initials: YJ
authors.lastname: Hao
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects / Q000235:genetics*; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000502:physiology; D002118:Calcium / Q000378:metabolism; D003001:Cloning, Molecular; D003080:Cold Temperature; D055864:Droughts; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant / Q000235:genetics*; D018551:Solanum lycopersicum / Q000187:drug effects / Q000235:genetics* / Q000502:physiology; D027845:Malus / Q000187:drug effects / Q000235:genetics* / Q000502:physiology*; D008969:Molecular Sequence Data; D009995:Osmosis / Q000187:drug effects; D010802:Phylogeny; D010937:Plant Growth Regulators / Q000494:pharmacology; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics; D030821:Plants, Genetically Modified; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013014:SOS Response, Genetics / Q000187:drug effects; D054712:Salinity; D055049:Salt Tolerance / Q000187:drug effects / Q000235:genetics; D013312:Stress, Physiological / Q000187:drug effects / Q000235:genetics*
chemical_list: D010937:Plant Growth Regulators; D010940:Plant Proteins; D002118:Calcium