替码板栗芽体细胞程序性死亡中生长素相关基因的表达分析OA

To investigate the regulatory role of auxin(IAA)in the programmed cell death(PCD)of apical-bud-senescence chestnut buds,and to identify key candidate genes associated with auxin,this study used upper buds(with PCD)and lower buds(without PCD)collected from one-year shoots of apical-bud-senescence chestnut cultivar X12.The IAA content in both bud types was measured during the PCD period(20-30 days after flowering)using high-performance liquid chromatography(HPLC).At the same time,transcriptome sequencing and quantitative real-time PCR(qRT-PCR)were performed to analyze and identify the expression trends of IAA-related genes in upper(with PCD)and lower(without PCD)buds at different PCD developmental stages.The results showed that the plant hormone signal transduction pathway was the most significantly enriched pathway for differentially expressed genes(DEGs)during the transition from normal development to PCD in upper buds of apical-bud-senescence chestnut.During PCD,the IAA content in upper buds increased dramatically,which was consistent with the up-regulated expressions of IAA biosynthesis-related genes(FMO1 and YUCCA10).Concurrently,in the IAA signal transduction pathway,most positive regulators(such as SAUR and GH3)were significanlty up-regulated,whereas most negative regulators(such as AUX/IAA)were down-regulated.These findings preliminarily suggest that IAA acts a positive regulator in the PCD of upper buds in chestnut cultivar X12.Based on IAA contents,expression patterns of IAA-related synthesis and signaling genes,fold changes in gene expression at different stages,and protein-protein interaction network scores,six key IAA-related candidate genes regulating chestnut bud PCD were identified:EVM0022587(FMO1),EVM0003671(SAUR36),EVM0017283(SAUR32),EVM0030681(IAA16),EVM0020355(IAA27)and EVM0032825(ARF9).This study laid a foundation for the cloning and functional verification of PCD-related genes in apical-bud-senescence chestnut buds.