Expression profiling and functional characterization of a CBL-interacting protein kinase gene from Populus euphratica

Abstract

This is the first report on the function of a member of the CIPK family in Populus euphratica. The Ca(2+)-dependent salt overly sensitive (SOS) pathway has been shown to play an essential role in maintaining ion homeostasis and conferring salt tolerance. One component of the SOS pathway, SOS1, was identified in the salt-resistant tree P. euphratica. In this study, we identified and functionally characterized another component of the SOS pathway in this tree called PeSOS2 or PeCIPK26. On the basis of protein sequence similarity and complementation studies in Arabidopsis, PeCIPK26 was concluded to be the functional homolog of Arabidopsis AtSOS2. Yeast two-hybrid assays revealed that PeCIPK26 can interact with four calcineurin B-like (CBL) genes, i.e., PeCBL1, PeCBL4/PeSOS3, PeCBL9 and PeCBL10. Autophosphorylation assays showed that PeCIPK26 is an active protein kinase. Expression profile analysis demonstrated that PeCIPK26 is expressed in root, stem and leaf, and throughout the cell including cell membrane, cytoplasm and nucleus; in addition, it can be induced under salt-stress treatment. Functions of PeCIPK26 in salt tolerance were evaluated by gene overexpression in Arabidopsis cipk24 mutants. The better salt tolerance of transgenic plants relative to mutants was shown by their higher germination rate, lower Na(+) accumulation and higher capacity to discharge Na(+) when grown with NaCl. These results suggest the involvement of PeCIPK26 in the salt-stress response of P. euphratica.

GhCIPK6a increases salt tolerance in transgenic upland cotton by involving in ROS scavenging and MAPK signaling pathways

“…CBLs generally interact with CIPKs to form CBL-CIPK complexes that regulate downstream target proteins. CIPK proteins and CBL-CIPK complexes were involved in various responsive processes in Arabidopsis and other plants, such as rice (Oryza sativa) [26][27][28][29], maize (Zea mays) [30][31][32], Populus euphratica [33,34], canola (Brassica napus) [35,36], eggplant (Solanum melongena) [37], tomato (Solanum lycopersicum) [38], foxtail millet (Setaria italica (L.) P. Beauv) [39], pineapple (Ananas comosus) [40] and cotton [41][42][43][44]. CIPKs and CBL-CIPK complex have been implicated in the plant's response to abiotic stresses, biotic stresses, phytohormones, and nutrient deprivation [45][46][47][48][49][50].…”

Physiological and transcriptome analysis of heteromorphic leaves and hydrophilic roots in response to soil drying in desert Populus euphratica

“…Some plants, for example trees, have evolved distinct morphological and physiological traits 2 , and exhibit strong tolerance to water shortage than other plants 3 . The desert popular, Populus euphratica (Olivier), is a unique tree that can survive in the serious desert environments (Figure S1 ) and exhibits remarkable tolerance to environmental stresses 4 . Due to its greater ability to cope with environmental stresses, P. euphratica is widely considered as an ideal model system when studying the molecular mechanisms of abiotic stress responses in woody species 4 – 10 .…”

Genome-Wide Analysis of MicroRNA Responses to the Phytohormone Abscisic Acid in Populus euphratica

“…Populus euphratica (P. euphratica) , which exhibits remarkable tolerance to environmental stresses, is among a few tall tree that can survives in saline and alkaline area. It is a model woody plant for studying the molecular mechanisms of abiotic stress responses (Ye et al, 2009 ; Lv et al, 2014 ). Previous studies show miRNA participate in the drought and salt stress responses of P. euphratica , and the high-throughput sequencing has widely been used in miRNA research of P. euphratica (Li et al, 2011 , 2013 ; Si et al, 2014 ), while other species poplus also involved in stress response (Ren et al, 2012 , 2013 , 2015 ; Chen et al, 2012a , b , 2015 ; Shuai et al, 2013 ).…”