Cryptochrome 1a Fine-Tunes Blue Light Responses during Tomato Seed Germination by Coordinating Redox Homeostasis and Carbon Metabolism
摘要
Tomato (Solanum lycopersicum L.) seed germination is influenced by both environmental and physiological factors, including light perception mediated by photoreceptors. In this study, we examined the role of blue light photoreceptor cryptochrome 1a (cry1a) in regulating tomato seed germination under blue light and dark conditions. Physiological and biochemical parameters were analyzed in seeds of the cv. Moneymaker (wild-type, WT) and the cry1a loss-of-function mutant. The results showed that blue light negatively affected germination percentage in both genotypes; however, this inhibitory effect was more pronounced in cry1a seeds, suggesting that cry1a positively regulates germination under this light condition. WT seeds showed increased levels of hydrogen peroxide (H2O2), particularly under blue light, indicating that cry1a may play a role in regulating the production of reactive oxygen species during germination. No significant differences were noted in the accumulation of malondialdehyde (MDA). Under dark conditions, cry1a seeds exhibited higher proline content after 72 h of imbibition. In addition, cry1a seeds accumulated more total sugars and sucrose, particularly in the dark, suggesting that the absence of cry1a may impair the efficient utilization of these reserves. These findings demonstrate that cry1a acts both as a blue-light sensor and as a regulator of redox balance and early carbon metabolism during tomato seed germination.