Overexpression of the Tibetan Plateau annual wild barley (Hordeum spontaneum) HsCIPKs enhances rice tolerance to heavy metal toxicities and other abiotic stresses

Weihuai Pan,Zhongzhong Zheng,Wenxiang Wang,Jianwei Pan,Lixi Jiang,Jinqiu Shen,Xu Yan,Jianxin Shou

doi:10.1186/s12284-018-0242-1

Weihuai Pan, Zhongzhong Zheng + Show 6 more

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https://doi.org/10.1186/s12284-018-0242-1

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Abstract

BackgroundThe calcineurin B-like protein (CBL) and CBL-interacting protein kinase (CIPK) signaling system plays a key regulatory role in plant stress signaling. The roles of plant-specific CIPKs, essential for CBL-CIPK functions, in the response to various abiotic stresses have been extensively studied so far. However, until now, the possible roles of the CIPKs in the plant response to heavy metal toxicities are largely unknown.ResultsIn this study, we used bioinformatic and molecular strategies to isolate 12 HsCIPK genes in Tibetan Plateau annual wild barley (Hordeum spontaneum C. Koch) and subsequently identified their functional roles in the response to heavy metal toxicities. The results showed that multiple HsCIPKs were transcriptionally regulated by heavy metal toxicities (e.g., Hg, Cd, Cr, Pb, and Cu) and other abiotic stresses (e.g., salt, drought, aluminum, low and high temperature, and abscisic acid). Furthermore, the ectopic overexpression of each HsCIPK in rice (Oryza sativa L. cv Nipponbare) showed that transgenic plants of multiple HsCIPKs displayed enhanced tolerance of root growth to heavy metal toxicities (Hg, Cd, Cr, and Cu), salt and drought stresses. These results suggest that HsCIPKs are involved in the response to heavy metal toxicities and other abiotic stresses.ConclusionsTibetan Plateau annual wild barley HsCIPKs possess broad applications in genetically engineering of rice with tolerance to heavy metal toxicities and other abiotic stresses.

Highlights

The calcineurin B-like protein (CBL) and calcineurin B-like proteins (CBLs)-interacting protein kinase (CIPK) signaling system plays a key regulatory role in plant stress signaling
We functionally identified the roles of 12 members of the Tibetan plateau annual wild barley HsCIPK family in the response to heavy metal toxicities, including Hg, Cd, Cr, Cu, and Pb, and other abiotic stresses such as salt, drought, Al, low and high temperature, and abscisic acid (ABA)
In silico assay of cultivated barley HvCIPKs To obtain the HvCIPK cDNA sequences of cultivated barley, we performed an in silico assay to search for the corresponding homologous CBL-interacting protein kinase (CIPK) in a full-length cDNA library of cultivated barley using the full-length cDNAs of rice OsCIPK1 to OsCIPK31 (Kolukisaoglu et al 2004) as probes and subsequently recovered five rice homologous sequences of HvCIPKs, including CIPK2, − 9, − 11, − 23, and − 28

Summary

Introduction

The calcineurin B-like protein (CBL) and CBL-interacting protein kinase (CIPK) signaling system plays a key regulatory role in plant stress signaling. The roles of plant-specific CIPKs, essential for CBL-CIPK functions, in the response to various abiotic stresses have been extensively studied so far. Functional identification of the CIPKs in distinct plant species will enhance the better understanding of the functional roles and modes of action of the CBL-CIPK signaling system. Bioinformatic analysis has shown that there are 26 and 31 CIPK homologous genes in the model plant genomes of Arabidopsis thaliana and rice (Oryza sativa), respectively (Kolukisaoglu et al 2004). Tibetan plateau wild barley is one of the few germplasm resources to utilize wild barley CIPKs to genetically engineer rice or other crops with higher stress tolerance

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