OVEREXPRESSION OF PTRLEA7, A LATE EMBRYOGENESIS ABUNDANT FAMILY GENE FROM PONCIRUS TRIFOLIATA, CONFERS ENHANCED DROUGHT TOLERANCE BY ENHANCING ANTIOXIDANT CAPACITY

Highlights

• A LEA family gene (PtrLEA7)was cloned from Poncirus trifoliata.

• PtrLEA7was strongly induced by stresses and ABA.

• PtrLEA7played a positive role in modulation of drought tolerance.

• Overexpression of PtrLEA7elevated antioxidant capacity.

Abstract

Late embryogenesis abundant (LEA) genes encode highly hydrophilic proteins that are essential in abiotic stress responses. However, most LEA genes in higher plants have not yet been investigated. This study identified an LEA family gene (PtrLEA7) from Poncirus trifoliata and studied its function in drought tolerance. The full-length coding sequence of PtrLEA7 was 420 bp encoding a protein of 139 amino acids. Phylogenetic analysis shows that PtrLEA7 protein belongs to the LEA_4 subfamily. Expression profiling by qPCR found that PtrLEA7 was strongly induced by dehydration, cold and ABA treatments, and slightly induced by salt stress. Subcellular localization reveals that PtrLEA7 protein was located in both cytoplasm and nucleus. To investigate its function, transgenic plants of both tobacco and Poncirus trifoliata overexpressing PtrLEA7 were obtained. Stress tolerance assays show that overexpression lines had enhanced dehydration and drought tolerance compared with wild type plants, indicating that PtrLEA7 positively regulates drought tolerance. In addition, transgenic plants had much higher expression levels of three antioxidant enzyme genes (CAT, SOD and POD) and significantly increased catalase enzyme activity, accompanied by reduced reactive oxygen species accumulation in comparison with wild type plants. Collectively, this study demonstrates that PtrLEA7 can confer enhanced drought tolerance partially via enhancing antioxidant capacity.

Graphical abstract

Keywords

abiotic stress / antioxidant / drought / late embryogenesis abundant / Poncirus trifoliata

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Supplementary materials

The online version of this article at https://doi.org/10.15302/J-FASE-2020368 contains supplementary materials (Tables S1–S2; Figs. S1–S2 ).

Acknowledgements

This work was supported by the National Key Research and Development Program of China (2018YFD1000300), the National Natural Science Foundation of China (31972377), Hubei Provincial Natural Science Foundation for Innovative Group (2017CFA018), and Leading Talents Fund in Science and Technology Innovation in Henan Province (194200510007).

Compliance with ethics guidelines

Tonglu Wei, Dalong Guo, and Jihong Liu declare that they have no conflicts of interest or financial conflicts to disclose. This article does not contain any studies with human or animal subjects performed by any of the authors.

RIGHTS & PERMISSIONS

The Author(s) 2020. Published by Higher Education Press. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0)