One gene for taller, stiffer and high-yield rice

Wang et al. reveal that MYB110 serves as a phosphate-dependent negative regulator of plant height that could be manipulated to boost lodging resistance and yield.

https://doi.org/10.1093/plcell/koad268

Tingting Wang,¹ Ming Yan,² Mian Gu,¹ Guohua Xu¹

1 National Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China

2 MOA Key Laboratory of Grain Crop Genetic Resources Evaluation and Utilization, Shanghai Agrobiological Gene Center, Shanghai 201106, China

Background: The semi-dwarf architecture of the ‘Green Revolution’ crop varieties, which confers remarkably enhanced lodging resistance, is a fundamental basis for high yield. To further boost yield, developing novel crop varieties with higher plant height and improved lodging resistance could be a potential solution. Plant height is tightly regulated by the availability of phosphate (Pi), an essential nutrient for plant growth and development, yet the underlying mechanism remains obscure.

Question: What are the molecular mechanisms by which rice plants coordinately regulate plant height and lodging resistance in response to varied Pi availabilities?

Findings: An R2R3-type MYB transcription factor in rice (Oryza sativa), OsMYB110, is a Pi-dependent negative regulator of plant height. Inactivation of OsMYB110 increased culm diameter and bending resistance, leading to enhanced lodging resistance in spite of increased plant height. We demonstrated that OsMYB110 is a direct target of OsPHR2 (PHOSPHATE STARVATION RESPONSE 2), the central regulator of Pi starvation signaling network in rice, and is responsible for OsPHR2-induced suppression of plant height. The response of plant height to Pi-limiting stress was largely compromised upon OsMYB110 inactivation. Strikingly, the grain yield of osmyb110 mutants was elevated under both high- and low-Pi regimes. Furthermore, we identified two indica-japonica divergent haplotypes based on single-nucleotide polymorphisms in the putative promoter of OsMYB110, which correlates with OsMYB110 transcript level and plant height in response to Pi availability.

Next steps: We plan to introduce the OsMYB110 haplotype with lower expression, which confers enhanced plant height and lodging resistance, into widely planted rice cultivars by generating near isogenic lines.

Reference:

Tingting Wang, Yi Jin, Lixiao Deng, Feng Li, Zhiyuan Wang, Yuanyuan Zhu, Yufeng Wu, Hongye Qu, Shunan Zhang, Ying Liu, Hanwei Mei, Lijun Luo, Ming Yan,*, Mian Gu*, Guohua Xu* (2023) Transcription factor MYB110 regulates plant height, lodging resistance and grain yield in rice. https://doi.org/10.1093/plcell/koad268