Open Access

ARTICLE

Overexpression of IbSINA5 Increases Cold Tolerance through a CBF SINA-COR Mediated Module in Sweet Potato

by Shiyang Li^1,#, Xue-Ao Liu^2,#, Lizi Zhao², Huiqing Huang³, Bei Li², Zhizhong Song², Meixia Liang², Hongxia Zhang^2,3, Limin Wang^2,*, Shenglin Zhou^1,*

1 Shandong Technology and Business University, Yantai, 264005, China
2 The Engineering Research Institute of Agriculture and Forestry, Ludong University, Yantai, 264025, China
3 School of Life Sciences, Ludong University, Yantai, 264025, China

* Corresponding Authors: Limin Wang. Email: ; Shenglin Zhou. Email:
# These authors contribute equally to this work

Phyton-International Journal of Experimental Botany 2021, 90(3), 761-772. https://doi.org/10.32604/phyton.2021.016314

Received 20 February 2021; Accepted 05 March 2021; Issue published 30 March 2021

Abstract

Seven in absentia (SINA) family proteins play a central role in plant growth, development and resistance to abiotic stress. However, their biological function in plant response to cold stress is still largely unknown. In this work, a seven in absentia gene IbSINA5 was isolated from sweet potato. Quantitative real-time polymerase chain reaction (qRT-PCR) analyses demonstrated that IbSINA5 was ubiquitously expressed in various tissues and organs of sweet potato, with a predominant expression in fibrous roots, and was remarkably induced by cold, drought and salt stresses. Subcellular localization assays revealed that IbSINA5-GFP fusion protein was mainly localized in cytoplasm and nucleus. Overexpression of IbSINA5 in sweet potato led to dramatically improved resistance to cold stress in transgenic plants, which was associated with the up-regulated expression of IbCOR (cold-regulated) genes, increased proline production, and decreased malondialdehyde (MDA) and H₂O₂ accumulation in the leaves of transgenic plants. Furthermore, transient expression of IbCBF3, a C-repeat binding factor (CBF) gene, in the leaf protoplasts of wild type sweet potato plants up-regulated the expression of both IbSINA5 and IbCOR genes. Our results suggest that IbSINA5 could function as a positive regulator in the cold signaling pathway through a CBF-SINA-COR mediated module in sweet potato, and have a great potential to be used as a candidate gene for the future breeding of new plant species with improved cold resistance.

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