Yuying Sun | PubMed Health

PubMed2025

Nitric oxide delays floral transition in Arabidopsis by inhibiting histone deacetylases HDA5 and HDA6.

Nitric oxide (NO), a reactive small molecule, plays a critical role in various developmental and physiological processes in living organisms. Previous studies by our group revealed that NO delays flowering in Arabidopsis by increasing transcript levels of the flowering repressor FLOWERING LOCUS C (FLC). In this study, we further investigated the molecular mechanism by which NO regulates FLC expression. Genetic experiments demonstrated that NO-induced delayed flowering specifically depends on elevated FLC transcript levels. Chromatin Immunoprecipitation assays revealed that NO significantly enhances histone H3 acetylation at the FLC locus. Biochemical analyses further showed that NO reduces total histone deacetylase activity through S-nitrosylation of histone deacetylases HDA5 and HDA6. Additionally, we identified and evaluated potential S-nitrosylation sites on HDA5 and HDA6, revealing their effects on deacetylase activity and floral regulation. Collectively, our findings uncover a novel mechanism by which NO mediates epigenetic modification to modulate flowering in Arabidopsis. This study sheds light on the functional network linking NO signaling, epigenetic modification, and flowering.

Arabidopsis↗

PubMed2025

Slmsh1-induced heritable enhancement of traits for tomato breeding improvement.

Vegetable grafting is a horticultural technique employed to develop specialized plant varieties by effectively enhancing resistance to both biotic and abiotic stresses, as well as improving fruit quality and yield. However, these advantageous traits are generally non-heritable. The MSH1 gene induced heritable enhancement-through-grafting (HEG) effect on growth vigor, demonstrating promising application potential. In this study, we employed the msh1 mutant tomato as a rootstock to induce heritable superior traits and combined this approach with hybridization techniques to enhance tomato cultivars. Three Slmsh1 mutants were generated using CRISPR/Cas9 which exhibited a dwarf phenotype with whitened spots. By grafting several distinct inbred lines onto Slmsh1, we observed significant HEG, drought stress tolerance, and fruit quality. Under drought conditions, Slmsh1-grafted tomato seedlings exhibited increased biomass and enhanced drought tolerance through the regulation of antioxidant enzyme activities. Differential expression and methylation analyses of the graft progeny revealed that these heritable enhanced traits (HETs) are likely attributable to epigenetic modifications in the expression of ROS-scavenging- and hormone-related genes. Furthermore, to explore practical applications, we crossed inbred lines with HETs and evaluated the growth, yield, and fruit quality of the resulting hybrid combinations. The results indicated that these hybrid combinations improved fruit yield and quality, enhancing the total soluble solids, soluble sugar, and soluble protein content. These findings suggest that Slmsh1-grafted progenies enhanced plant biomass and drought resistance, while their hybrid combinations positively influenced root growth, yield, and fruit quality, providing new insights into the synergistic integration of genome editing and conventional breeding.

Solanum lycopersicum↗