Expression pattern analysis of phytohormone metabolism and signal transduction pathways in the corm of Pisang Awak under strigolactones treatment

【Objective】 This study aimed to investigate key genes involved in hormone metabolism and signal transduction during corm growth and development of Pisang Awak under strigolactones （SLs） treatment and to elucidate the molecular mechanisms of SLs for regulating corm development of Pisang Awak， thereby providing theoretical basis for understanding the role of SLs in regulatory networks of growth and development of plants. 【Method】 The Pisang Awak cultivar Yufen No. 6 was used as experimental materials. Hydroponic method was adopted to treat 8-leaf-stage plants with 30 μmol/L rac-GR24 （synthetic analog of SLs） for simulating SLs treatment. The nutrient solution containing an equal volume of water served as the control （CK）. Corms were collected at 0， 15， 30， 60， 90， and 120 d after SLs treatment to measure corm height and diameter.Transcriptome sequencing was performed on corm tissues to screen differentially expressed genes （DEGs） between SLs treatment and CK. GO functional annotation and KEGG signaling pathway enrichment analysis were performed for DEGs， and real-time fluorescence quantitative PCR was conducted for validation. 【Result】 SLs treatment inhibited the elongation and thickening of corm. Transcriptome sequencing generated 35638662-45736762 clean reads. Screening results of DEGs revealed that， at different time after SLs treatment， the highest number of DEGs was found between 15 d after SLs treatment and CK， with 3943 up-regulated and 3704 down-regulated genes， indicating that 15 d after SLs treatment might be the active stage of gene expression regulation. GO functional annotation showed that DEGs were mainly involved in terms including metabolic process， biological regulation， response to stimulus， and regulation of biological process； KEGG signaling pathway enrichment analysis indicated that DEGs were significantly enriched pathways such as plant hormone signal transduction， starch and sucrose metabolism， and secondary metabolite biosynthesis. SLs treatment primarily affected gene family members involved in the metabolism of cytokinins （CTK）， indole-3-acetic acid （IAA）， abscisic acid （ABA）， jasmonic acid （JA）， gibberellins （GA）， and brassinosteroids （BRs） and CKX， NCED， GA20ox， CYP707A， and CYP90B. Real-time fluorescence quantitative PCR results confirmed the reliability of the transcriptome sequencing data. 【Conclusion】 SLs can inhibit corm growth of Pisang Awak and induce coordinated responses of multiple hormone metabolic and signaling pathways associated with corm growth and development， suggesting that SLs can work not only as individual developmental signaling molecules， but also as key nodes within complex phytohormone regulatory networks controlling corm growth and development for Pisang Awak.