Introduction
Phased small interfering RNAs (phasiRNAs) are crucial regulatory molecules in plants, involved in various biological processes such as development and stress responses. To advance the research on phasiRNAs, we have developed the Plant Phased siRNA Database (PPSD, https://cbi.njau.edu.cn/PPSD/index.php), which includes phasiRNA data from over 100 plant species. This database is built upon the PhasiHunter tool, employing two prediction algorithms and multiple reference sequences to enhance the accuracy of phasiRNA identification. PPSD offers comprehensive information on phasiRNAs, including their upstream phase-initiators and downstream target genes, and integrates degradome sequencing data for the validation of target genes.