(H. Lév.) Rehder is a rare, endangered, and therefore, protected tree species native to China. However, there are serious limitations to the effective protection of the species, including a low seed germination-rate and difficult storage due to a high seed oil-content. Here, we evaluated the feasibility of ultra-dry seed storage and its effects on seedling growth. We used the silica gel method to prepare ultra-dry seeds with different moisture contents to find an optimal moisture content range (2.54%–4.77%). Ultra-dry treatment improved storability of . Furthermore, seeds with a moisture content of 4.77% stored at room temperature, and seeds with a moisture content of 3.97% stored at 4 °C yielded the best results. Priming with an appropriate concentration of polyethylene glycol had a certain repairing effect on ultra-dry stored seeds and improved seed vigor, with a two-day priming treatment with 20% polyethylene glycol having the best effect. Finally, compared with sand storage at 4 °C, ultra-dry storage promoted seedling growth and root development; furthermore, it alleviated storage damage to seeds, promoted soluble sugar and soluble protein accumulation, and increased seedling nitrogen, phosphorus, and potassium uptake. Therefore, ultra-dry storage can be effectively used to preserve seeds. Specifically, low-temperature storage of ultra-dry seeds with a moisture content of 3.97% enhanced seed vigor, and seedling growth and development.Handeliodendron bodinieri H. bodinieri seeds H. bodinieri H. bodinieri H. bodinieri

Handeliodendron bodinieri has unisexual flowers with aborted stamens in female trees, which can be used to study unisexual flower development in tree species. To elucidate the molecular mechanism of stamen abortion underlying sex differentiation, the stage of stamen abortion was determined by semi-thin sections; results showed that stamen abortion occurred in stage 6 during anther development. In addition, differentially expressed transcripts regulating stamen abortion were identified by comparing the transcriptome of female flowers and male flowers with RNA-seq technique. The results showed that 14 genes related to anther development and meiosis such as HbGPAT, HbAMS, HbLAP5, HbLAP3, and HbTES were down-regulated, and HbML5 was up-regulated. Therefore, this information will provide a theoretical foundation for the conservation, breeding, scientific research, and application of Handeliodendron bodinieri.