Triacontanol Promotes the Fruit Development and Retards Fruit Senescence in Strawberry: A Transcriptome Analysis

Triacontanol (TA) is a non-toxic, pollution-free, low-cost, high-efficiency, broad-spectrum plant growth regulator that plays an important role in plant growth and development, but its regulation mechanism of strawberry (Sweet charlie, Fragaria × ananassa Duch.) fruit development is still unclear. In this study, we showed that TA treatment (50 μM) could promote fruit development by up-regulating factors related to fruit ripening-related growth and development. TA increased fruit sugar content and anthocyanin accumulation, and many stress-related enzyme activities. In the meantime, Illumina RNA-Seq technology was used to evaluate the effect of TA treatment on strawberry fruit senescence. The results showed that 9338 differentially expressed genes (DEGs) were obtained, including 4520 up-regulated DEGs and 4818 down-regulated DEGs. We performed gene ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of these DEGs. The results showed that TA treatment caused changes in transcript levels related to cellular processes, hormones and secondary metabolism, such as DNA metabolic processes, flavonoid synthesis, and plant hormone signal transduction. Bioinformatics analysis showed that many transcription factors were related to fruit maturity. Taken together, this study will provide new insights into the mechanism of strawberry development and postharvest response to TA treatment.