ORIGINAL RESEARCH article
Front. Plant Sci.
Sec. Plant Nutrition
Volume 16 - 2025 | doi: 10.3389/fpls.2025.1654599
OSH45, a Homeobox Transcription Factor, Coordinates Low-Phosphate Adaptation in Rice
Provisionally accepted
- 1Zhejiang University Life Sciences Institute, Hangzhou, China
- 2Hainan Institute of Zhejiang University, Sanya, China
Select one of your emails
You have multiple emails registered with Frontiers:
Notify me on publication
Please enter your email address:
If you already have an account, please login
You don't have a Frontiers account ? You can register here
Phosphorus (P), an essential macronutrient critical for plant growth and development, faces significant availability constraints in agricultural soils, substantially limiting crop yield potential. Transcription factors (TFs) play pivotal roles in phosphate (Pi) starvation responses in plants. In this study, we identified OSH45 (Oryza sativa homeobox 45), a homeobox domain TF in rice (Oryza sativa L.), which was strongly induced in roots under Pi starvation. Subcellular localization assays indicated that OSH45 is a nuclear localized protein. OSH45 overexpression transgenic plants exhibited enhanced low-Pi tolerance, characterized by significantly higher Pi concentrations and increased shoot and root biomass compared to wild type (WT) under Pi-limited conditions. Whereas osh45 loss-of-function mutants displayed no significant difference in shoot and root biomass compared to WT under both Pi-sufficient and Pilimited conditions, but showed lower Pi concentration under Pi-sufficient conditions. Through transcriptomic profiling, 2,406 differential expressed genes (DEGs) were identified in OSH45 overexpression plants versus WT under Pi-sufficient conditions. About 38% of Pi starvation-induced (PSI) genes were upregulated and 25% of Pi starvation-suppressed (PSS) genes were downregulated in OSH45 overexpression plants. The expression of phosphate transporters, such as OsPT1, OsPT2, OsPT4, OsPT8, and acid phosphatases was upregulated, while the expression of Pi signaling repressors OsSPX1-3 was suppressed in OSH45 overexpression plants. Conversely, osh45 displayed decreased expression of OsPT1 and OsPT8 compared to WT.Altogether, our findings demonstrated that OSH45 is a novel TF involved in Pi deficiency response, regulating a set of Pi starvation responsive (PSR) genes to optimize plant adaptation to Pi-limited environments. This mechanism provides a strategic target for engineering Pi-efficient crops.
Keywords: Oryza sativa L., Phosphate starvation, knotted1-like homeobox protein, Transcriptome, phosphate transporter
Received: 26 Jun 2025; Accepted: 01 Aug 2025.
Copyright: © 2025 Lu, Jin, Luo, Wu, Liu, Xu and Mao. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Chuanzao Mao, Zhejiang University Life Sciences Institute, Hangzhou, China
Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.