Poplar calcineurin B-like proteins PtCBL10A and PtCBL10B regulate shoot salt tolerance through interaction with PtSOS2 in the vacuolar membrane.
The calcineurin B-like protein (CBL) family represents a unique group of calcium sensors in plants. In Arabidopsis, CBL10 functions as a shoot-specific regulator in salt tolerance. We have identified two CBL10 homologs, PtCBL10A and PtCBL10B, from the poplar (Populus trichocarpa) genome. While PtCBL10A was ubiquitously expressed at low levels, PtCBL10B was preferentially expressed in the green-aerial tissues of poplar. Both PtCBL10A and PtCBL10B were targeted to the tonoplast and expression of either one in the Arabidopsis cbl10 mutant could rescue its shoot salt-sensitive phenotype. Like PtSOS3, both PtCBL10s physically interacted with the salt-tolerance component PtSOS2. But in contrast to the SOS3-SOS2 complex at the plasma membrane, the PtCBL10-SOS2 interaction was primarily associated with vacuolar compartments. Furthermore, overexpression of either PtCBL10A or PtCBL10B conferred salt tolerance on transgenic poplar plants by maintaining ion homeostasis in shoot tissues under salinity stress. These results not only suggest a crucial role of PtCBL10s in shoot responses to salt toxicity in poplar, but also provide a molecular basis for genetic engineering of salt-tolerant tree species.
National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai, 200032, China.
Ren-Jie
RJ
Tang
Yang
Y
Yang
Lei
L
Yang
Hua
H
Liu
Cui-Ting
CT
Wang
Meng-Meng
MM
Yu
Xiao-Shu
XS
Gao
Hong-Xia
HX
Zhang
D000595:Amino Acid Sequence; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000378:metabolism; D019703:Calcineurin / Q000737:chemistry / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D005453:Fluorescence; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D005816:Genetic Complementation Test; D007425:Intracellular Membranes / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D018515:Plant Leaves / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000378:metabolism; D018520:Plant Shoots / Q000502:physiology*; D018547:Plant Stems / Q000378:metabolism; D030821:Plants, Genetically Modified; D032107:Populus / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D011188:Potassium / Q000378:metabolism; D011485:Protein Binding; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D055049:Salt Tolerance / Q000235:genetics / Q000502:physiology*; D016415:Sequence Alignment; D012964:Sodium / Q000378:metabolism; D013347:Subcellular Fractions / Q000378:metabolism; D014617:Vacuoles / Q000378:metabolism*
D029681:Arabidopsis Proteins; D010940:Plant Proteins; D012964:Sodium; D019703:Calcineurin; D011188:Potassium; D002118:Calcium
PtCBL10; salt tolerance; transgenic poplar