2. Academic Validation
  3. OsPHI-2 Controls Rice Growth and Development Through OSH1-Dependent Transcriptional Repression

OsPHI-2 Controls Rice Growth and Development Through OSH1-Dependent Transcriptional Repression

  • Physiol Plant. 2026 Jan-Feb;178(1):e70739. doi: 10.1111/ppl.70739.
Gan Wang 1 2 3 4,  Zhengli Jiao 5 6,  Yusang Wang 1 3,  Jian Li 1 2,  Rufang Deng 1 2,  Kuaifei Xia 1 2,  Mingyong Zhang 1 2
Affiliations

Affiliations

  • 1 Guangdong Provincial Key Laboratory of Applied Botany, State Key Laboratory of Plant Diversity and Specialty Crops, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, Guangdong, China.
  • 2 South China National Botanical Garden, Guangzhou, China.
  • 3 University of Chinese Academy of Sciences, Beijing, China.
  • 4 Zhanjiang Key Laboratory of Tropical Crop Genetic Improvement, South Subtropical Crops Research Institute, Chinese Academy of Tropical Agricultural Sciences, Zhanjiang, Guangdong, China.
  • 5 Innovation Center for Cell Signal Transduction and Synthetic Biology, School of Life Sciences, Guangzhou University, Guangzhou, China.
  • 6 Guangzhou University Branch Center of State Key Laboratory of Non-Food Biomass Energy Technology, Guangzhou University, Guangzhou, China.
PMID: 41549841 DOI: 10.1111/ppl.70739
Abstract

Phosphorus (P) scarcity severely limits crop productivity; yet, mechanisms balancing P allocation between vegetative and reproductive organs remain unclear. Here, we identify OsPH-2 as a phosphate-responsive regulator in rice (Oryza sativa L.). Under low-P (LP) conditions, OsPHI-2 is transcriptionally repressed by the KNOX family factor OSH1 (KNOX family class 1 homeobox gene of rice), which directly binds its promoter. CRISPR-edited OsPHI-2 knockout lines exhibited enhanced biomass and adaptive root-shoot resource allocation under LP, whereas overexpression lines showed impaired panicle development and reduced grain yield. This repression fine-tunes P partitioning by modulating expression of transporters (OsPT2, OsPHO1;2) and vacuolar effluxes (OsVPE1), prioritizing reproductive over vegetative sinks. Haplotype analysis indicated that subspecies-specific P remobilization strategies may be associated with OsPHI-2. Under P deficiency, Indica rice rapidly suppresses OsPHI-2 expression to preferentially remobilize P to panicles, thereby enhancing adaptation to low-P environments. Our study uncovers an OSH1-OsPHI-2 module that coordinates P allocation, providing a genetic target for improving P-use efficiency in rice.

Keywords

OSH1; OsPHI‐2; development; phosphorus; rice (Oryza sativa L.).

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