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The trihelix transcription factor OsGTγ-2 is involved adaption to salt stress in rice

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OsGTγ-2, a trihelix transcription factor, is a positive regulator of rice responses to salt stress by regulating the expression of ion transporters.

Abstract

Salinity stress seriously restricts rice growth and yield. Trihelix transcription factors (GT factors) specifically bind to GT elements and play a diverse role in plant morphological development and responses to abiotic stresses. In our previous study, we found that the GT-1 element (GAAAAA) is a key element in the salinity-induced OsRAV2 promoter. Here, we identified a rice OsGTγ family member, OsGTγ-2, which directly interacted with the GT-1 element in the OsRAV2 promoter. OsGTγ-2 specifically targeted the nucleus, was mainly expressed in roots, sheathes, stems and seeds, and was induced by salinity, osmotic and oxidative stresses and abscisic acid (ABA). The seed germination rate, seedling growth and survival rate under salinity stress was improved in OsGTγ-2 overexpressing lines (PZmUbi::OsGTγ-2). In contrast, CRISPR/Cas9-mediated OsGTγ-2 knockout lines (osgtγ-2) showed salt-hypersensitive phenotypes. In response to salt stress, different Na+ and K+ acclamation patterns were observed in PZmUbi::OsGTγ-2 lines and osgtγ-2 plants were observed. The molecular mechanism of OsGTγ-2 in rice salt adaptation was also investigated. Several major genes responsible for ion transporting, such as the OsHKT2; 1, OsHKT1; 3 and OsNHX1 were transcriptionally regulated by OsGTγ-2. A subsequent yeast one-hybrid assay and EMSA indicated that OsGTγ-2 directly interacted with the promoters of OsHKT2; 1, OsNHX1 and OsHKT1; 3. Taken together, these results suggest that OsGTγ-2 is an important positive regulator involved in rice responses to salt stress and suggest a potential role for OsGTγ-2 in regulating salinity adaptation in rice.

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Funding

This work was supported by the Genetically Modified Breeding Major Projects (No. 2016ZX08010-002-008), the National Natural Science Foundation of China (No. 31501239 and No. 31701405), the National Key Research and Development Program (No. 2017YFD0301304) and the Natural Science Foundation of Anhui Province (No. 1708085QC60).

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Author notes

  1. Xiaoshuang Liu, Dechuan Wu, Tiaofeng Shan contributed equally to this work.

Authors and Affiliations

  1. College of Agronomy, Anhui Agricultural University, Hefei, 230036, China

    Xiaoshuang Liu, Dechuan Wu, Tiaofeng Shan, Shanbin Xu & Dexiang Wu

  2. Key Laboratory of Rice Genetics & Breeding of Anhui Province, Institute of Rice Research, Anhui Academy of Agricultural Science, Hefei, 230031, China

    Xiaoshuang Liu, Ruiying Qin, Hao Li & Juan Li

  3. Rice Research Department, Field Crops Research Institute, Agricultural Research Center, Giza, Egypt

    Mahrous Negm

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  1. Xiaoshuang Liu
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  2. Dechuan Wu
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  3. Tiaofeng Shan
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  4. Shanbin Xu
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  5. Ruiying Qin
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  6. Hao Li
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  7. Mahrous Negm
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  8. Dexiang Wu
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  9. Juan Li
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Contributions

XL, DCW, TS and JL conceived and designed the experiments. XL, TS, SX and RQ conducted experiments. HL and DXW analyzed data and produced the figures. MN, DXW, and JL wrote the manuscript.

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Correspondence to Dexiang Wu or Juan Li.

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The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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Accession numbers

Sequence data from this article can be found in GenBank under the following accession numbers: OsACTIN1(Os03g0718100), OsNHX1(Os07g0666900), OsHKT2; 1(Os06g0701700), OsHKT1; 1(Os04g0607500), OsHKT1; 5(Os01g0307500), OsHKT1; 3(Os02g0175000), OsSOS1(Os12g0641100), OsABA8ox1(Os02g0703600), OsABA8ox2 (Os08g0472800), OsNCED2(Os12g0435200), OsNCED3(Os03g0645900), OsLEA3 (Os05g0542500), Rab16 (Os011g0454300).

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Liu, X., Wu, D., Shan, T. et al. The trihelix transcription factor OsGTγ-2 is involved adaption to salt stress in rice. Plant Mol Biol 103, 545–560 (2020). https://doi.org/10.1007/s11103-020-01010-1

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