Systematic identification and characterization of Group Ⅳ WRKYs in Osmanthus fragrans and induction of salt-sensitivity by OfWRKY157
Osmanthus fragrans is a horticulturally and economically significant species grown for greening, beautification, and fragrance. However, there have been few reports on the response of O. fragrans to salt stress thus far. The WRKY transcription factor (TF) family participates in the salt stress respo...
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| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2025-09-01
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| Series: | Plant Stress |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2667064X25002246 |
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| Summary: | Osmanthus fragrans is a horticulturally and economically significant species grown for greening, beautification, and fragrance. However, there have been few reports on the response of O. fragrans to salt stress thus far. The WRKY transcription factor (TF) family participates in the salt stress responses of various plant species. Group Ⅳ WRKY TFs are relatively unique because they contain only one WRKY domain with no zinc finger structures; their function in abiotic stress is still uncertain. We identified eight Group Ⅳ OfWRKYs from the O. fragrans genome. Three were differentially expressed in O. fragrans tissues, and only OfWRKY157 was induced dramatically under salt stress. OfWRKY157 exhibited nuclear localization but was transcriptionally inactive in yeast assays. Agrobacterium tumefaciens-mediated transient transformation was employed to introduce OfWRKY157 into O. fragrans callus and Nicotiana benthamiana, followed by salt stress treatment. Compared to the control, O. fragrans callus displayed significantly enhanced 3,3′-diaminobenzidine (DAB) staining, elevated malondialdehyde (MDA) levels, and reduced superoxide dismutase (SOD) activity. Additionally, N. benthamiana exhibited intensified nitroblue tetrazolium (NBT) staining and a substantial increase in relative electrolyte leakage (REL), further indicating oxidative stress and membrane damage. The quantitative real-time PCR (qRT-PCR) and dual-luciferase reporter assays revealed that OfWRKY157 negatively regulated the expression of OfSOD1. In conclusion, overexpression of OfWRKY157 conferred sensitivity under salt stress, laying a foundation for exploring the functions of Group Ⅳ WRKYs and significantly enhancing its cultivation in increasingly saline-affected horticultural landscapes. |
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| ISSN: | 2667-064X |