LF1 mediates brassinosteroid signaling to regulate leaf angle development in rice.

OsELP3/ELP4, rice Elongator factor complex subunits, epigenetically regulates rice blast resistance.

Rice blast, caused by Magnaporthe oryzae (M.oryzae), is one of the three most devastating rice diseases, significantly reducing both yield and grain quality. The Elongator complex, first characterized in Arabidopsis thaliana, regulates growth, development, and innate immunity by tightly associating with hyperphosphorylated RNA polymerase II. However, its immunological role in rice remains unexplored. Here, we demonstrate that Elongator plays an essential role in rice blast resistance. The OsELP3 subunit mutant exhibited susceptibility to M.oryzae, while its overexpression increased resistance. OsELP3 interacts with its homologous subunit OsELP4 in the nucleus, and that OsELP4 also positively regulates rice blast resistance. RNA-seq and histone acetylation analyses demonstrated that OsELP3/ELP4 enhances transcriptional activation of key rice blast resistance genes by modulating histone acetylation levels in both the jasmonic acid (JA) signaling pathway (OsAOS1, OsLOX6, OsPROPEP3) and lignin biosynthesis pathway (OsMYB30, OsMYB55, OsMYB110), thereby strengthening plant defense mechanisms against M. oryzae. These findings reveal that OsELP3/ELP4 regulates histone acetylation-mediated defense responses against M.oryzae, providing both theoretical foundations and genetic resources for developing blast-resistant rice cultivars.

Brassinosteroid-auxin crosstalk shapes rice flag leaf angle to boost dense planting yield

Flag leaf angle (FLA) critically determines rice yield potential under dense planting conditions. As two pivotal phytohormones determine rice FLA, the antagonistic interaction between brassinosteroid (BR) and auxin remains largely uncharacterized. We here demonstrate that BR signaling reduces auxin biosynthesis to control FLA via regulating the biosynthesis of secondary cell wall (SCW). Genetic evidence demonstrates OsYUC8 mutants disrupt SCW formation, leading to increased FLA. At the molecular level, the BR-related transcription factor OsBZR1 directly binds to and represses OsYUC8 promoter activity, thereby fine-tuning auxin-mediated SCW biosynthesis. Field evaluations reveal that osbzr1 mutants display optimized flag leaf architecture and improved yield performance under high-density cultivation. Our study not only delineates the antagonistic BR-auxin interaction governing FLA but also establishes a genetic strategy for manipulating crop architecture to maximize yield in dense planting conditions. One-sentence summary OsBZR1-mediated repression of OsYUC8-driven auxin biosynthesis modulates secondary cell wall formation to optimize flag leaf architecture, providing a genetic strategy for maximizing yield under high-density cultivation.

LfiRAV7 antagonizes LfiGI to regulate gibberellin biosynthesis and modulate plant height of crape myrtle.

Arabidopsis HY5 enhances jasmonate responses by directly suppressing the expression of the JAZ1 gene in a FIN219/JAR1-dependent manner

Light is a key environmental signal that regulates plant growth and development. ELONGATED HYPOCOTYL 5 (HY5), a bZIP transcription factor, is a central positive regulator of photomorphogenesis in Arabidopsis thaliana, integrating light and hormone signaling pathways. However, the molecular role of HY5 in jasmonate (JA) signaling remains unclear. Here, we show that methyl jasmonate (MeJA) substantially induces HY5 protein accumulation in a FIN219/JAR1-dependent manner. Genetic evidence indicates that HY5 and FIN219 act synergistically to inhibit hypocotyl growth and coordinate defense-related transcriptional networks. Loss of HY5 function results in hypersensitivity to MeJA-mediated inhibition of hypocotyl elongation, and transcriptomic analyses reveal disturbances in numerous light- and JA-responsive genes. HY5 represses JAZ1 expression by binding to its G-box-containing promoter and physically interacts with JAZ1, suggesting both transcriptional and post-translational regulation. Furthermore, HY5 and MYC2 compete for binding at the JAZ1 promoter, modulating JA responses under far-red light. Together, our findings uncover a regulatory mechanism in which HY5 fine-tunes JA signaling and seedling development by integrating light and hormone cues. This work provides new insights into HY5-mediated crosstalk and identifies potential targets to improve stress resilience in crops.

OsMYB8-OsARF12/25 module fine-tunes tiller angle via auxin signaling pathway in rice.

Tiller angle is a critical determinant of rice plant architecture and significantly impacts grain yield by influencing planting density and photosynthetic efficiency. Although auxin signaling is known to affect tiller angle in rice, the detailed regulatory networks remain largely unknown. In this study, we identify OsMYB8, an R2R3-MYB transcription factor, as a positive regulator of rice tiller angle. Functional analyses revealed that loss-of-function mutants of OsMYB8 exhibited reduced tiller angles and a more compact architecture, while overexpression of OsMYB8 resulted in more expanded tiller angles. Further investigations found that OsMYB8 might negatively regulate the shoot gravitropic response by disrupting asymmetric auxin distribution. At the molecular level, OsMYB8 directly binds to the promoters of two auxin response factors, OsARF12 and OsARF25, and represses their transcription. Genetic analyses confirmed that OsMYB8 acts upstream of OsARF12 and OsARF25 in regulating rice tiller angle. Our finding elucidates a previously uncharacterized OsMYB8-OsARF12/25 transcriptional module that fine-tunes auxin signaling to regulate tiller angle in rice, and offers valuable genetic targets for the optimization of rice architecture and yield potential.

A CLV3-WUS positive feedback loop in individual cells enhances shoot stem cell thermotolerance in Arabidopsis.

A positive feedback loop between CLV3 and WUS that is mediated by multiple hormone interactions, which is critical for plants to adapt to harsh environments is revealed.