Studies on Seed Germination Regulation in Oryza Accessions and Post-Transcriptional RNA Regulation During Seed Maturation

Abstract

Seed dormancy and germination are important processes that influence plant growth and productivity in Oryza. This study aimed to investigate the factors regulating seed dormancy and germination among different Oryza accessions, including both cultivated and wild accessions, and to examine post-transcriptional RNA regulation during seed maturation. Germination analyses were conducted through dormancy level identification, water uptake analysis, barrier and husk-related treatments, and gibberellic acid (GA3) induction experiments. On the other hand, post-transcriptional regulation was evaluated using a processed RNA-seq dataset of O. sativa seeds at 14 and 42 days after pollination (DAP). The results indicated significant variation in germination performance among Oryza accessions, indicating differences in dormancy regulation. Water uptake and husk-removal analyses suggested that the physical barrier imposed by the husk was not the primary factor limiting germination, while GA3 responses indicated the involvement of hormonal regulation. Furthermore, correlation analysis between gene expression changes and poly(A) tail length changes determined no correlation, supported by a Spearman’s correlation coefficient of ρ = 0.016. No overlap was observed between the genes exhibiting the largest expression changes and those exhibiting the largest poly(A) tail length changes. Overall, the findings suggest that seed dormancy and germination in Oryza are regulated by multiple physiological and hormonal factors, while transcriptional and poly(A) tail post-transcriptional regulation may operate independently during seed maturation.