Fruit Research (Jan 2024)
MAPK and hormone signaling and carotenoid biosynthesis pathways are involved in regulating flower opening of pear tree by response to temperature mediated by melatonin
Abstract
In recent years, the frequent occurrence of lower or higher temperatures in spring is becoming a serious threat to the pear industry in North China. Regulating the flower opening of pear trees is one of the methods to alleviate the threat. Ambient temperature is one of the pathways regulating plant flowering. Melatonin (MT) has been reported to be involved in flower opening of some plants except pear. Therefore, in this study, experiments were designed to explore whether melatonin can mediate temperature-regulating flower opening of pear trees to provide new ideas for reducing losses caused by dramatic temperature changes. The results showed that under higher temperature condition, compared with the control, 20 μM and 200 μM melatonin could delay pear flower opening, while 1,000 μM melatonin could accelerate pear flower opening. While under lower temperature conditions, all melatonin treatments could accelerate pear flower opening. Transcriptome analysis indicated that, compared with C1 group (the control) at a lower temperature, there were 610, 586 and 180 differentially expressed genes (DEGs) in T1, T2 and T3 group, respectively. Compared with the C2 group (the control) at a higher temperature, there were 384, 218, 349 DEGs in T4, T5 and T6 groups, respectively. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of DEGs showed that at lower temperatures, melatonin regulated the flower opening of pear mainly through the mitogen-activated protein kinase (MAPK) signaling pathway and the plant hormone signaling pathway. While at higher temperatures, melatonin regulated the flower opening of pear dependent on the carotenoid synthesis pathway. Several transcription factor families are involved in the above pathways, such as MYB, WRKY, AP2/EFR and NAC.
Keywords
