A CBL-Interacting Protein Kinase TaCIPK2 Confers Drought Tolerance in Transgenic Tobacco Plants through Regulating the Stomatal Movement

Abstract

In plants, the CBL-CIPK signaling pathways play key roles in the response to abiotic stresses. However, functional studies of CIPKs in the important staple crop wheat are very rare. In this study, we identified a CIPK gene from wheat, designated TaCIPK2. Expression analysis results showed that TaCIPK2 could be up-regulated in wheat leaves by polyethylene glycol, abscisic acid and H2O2 treatments. Subcellular localization analyses revealed that TaCIPK2 was present in whole wheat epidermal cells. A yeast two-hybrid assay indicated that TaCIPK2 interacted with TaCBL1, 2, 3 and 4 in vitro. Transgenic tobacco plants over-expressing TaCIPK2 exhibited increased drought tolerance, indicated by a larger proportion of green cotyledons and higher survival rates under the osmotic and drought stress conditions compared with control plants. Additionally, physiological index analyses revealed that the transgenic tobacco plants had lower water loss rates and ion leakage, accumulated less malondialdehyde and H2O2, and had higher catalase and superoxide dismutase activities than the control plants. The transgenic plants also exhibited faster stomatal closure following exposure to osmotic stress conditions. The seed germination rates and stomatal aperture of TaCIPK2-overexpressing tobacco plants decreased after exogenous abscisic acid treatment was applied, implying that the transgenic tobacco plants were more sensitive to exogenous abscisic acid than the control plants. Our results indicate that TaCIPK2 plays a positive regulatory role in drought stress responses in transgenic tobacco plants.

BdCIPK31, a Calcineurin B-Like Protein-Interacting Protein Kinase, Regulates Plant Response to Drought and Salt Stress

“…It was previously demonstrated that CIPKs participate in stress response through the ABA signaling pathway (Chen et al, 2012; Wang et al, 2016; Zhou et al, 2016). In the present study, BdCIPK31 increased plant sensitivity to ABA ( Figure 5 ), and accelerated ABA-mediated stomatal closure ( Figures 6C,D ).…”

TaCIPK10 interacts with and phosphorylates TaNH2 to activate wheat defense responses to stripe rust

“…The pairs of recombinant plasmids of AD and BD were co-transformed into yeast strain AH109 following the Yeast Protocols Handbook (Takara, Dalian, China). Protein expression in yeast was confirmed by Western blots following a previous study (Wang et al, 2016).…”

An apple sucrose transporter MdSUT2.2 is a phosphorylation target for protein kinase MdCIPK22 in response to drought

“…The expression of the P5CS1 gene is regulated by OsCIPK1, enhancing production of proline which acts as a cryoprotectant during cold stress and as osmolyte during drought stress in rice (Abdula et al ., ). Both wheat TaCIPK2 and Stipa purpurea SpCIPK26 positively regulate the expression CAT genes, thereby negatively modulating H 2 O 2 content (Wang et al ., ; Zhou et al ., ). TaCIPK27 interacts with calcineurin B‐like (CBL) proteins and positively regulates drought tolerance (Wang et al ., ).…”

“…Both wheat TaCIPK2 and Stipa purpurea SpCIPK26 positively regulate the expression CAT genes, thereby negatively modulating H 2 O 2 content (Wang et al ., ; Zhou et al ., ). TaCIPK27 interacts with calcineurin B‐like (CBL) proteins and positively regulates drought tolerance (Wang et al ., ). In this study, it was found that MdCIPK22 transgenic apple plant produced more sugars and exhibited higher drought tolerance than the WT control (Figures and ).…”