闽楠PHT基因家族鉴定及在低磷胁迫下的表达分析OA

[Objective]Phoebe bournei is a valuable tree species in southern regions of China,yet its plantation productivity is often constrained by low-phosphorus stress.This study aims to systematically characterize the P.bournei PHT gene family and elucidate its regulatory mechanisms under low phosphorus stress,providing a molecular basis for genetic improvement of phosphorus efficiency in P.bournei.[Method]Based on the whole-genome data of P.bournei,bioinformatics methods were employed to identify PHT family members,analyze their physicochemical properties,phylogenetic relationships,chromosomal localization,and cis-acting elements.Low phosphorus stress was applied to seedlings of different families,and reverse transcription real-time quantitative PCR(RT-qPCR)was utilized to detect expression patterns of key genes.[Result]A total of 48 PbPHT genes were identified,which distributed unevenly on 12 chromosomes,with 11 genes clustered on the LG02 chromosome.It classified into 5 subfamilies(PHT1-PHT5),with PHT3 being the l argest subfamily(24 members).Cis-element analysis revealed enrichment of hormone-responsive(40.6%)and stress-responsive elements(20.6%)in promoter regions of PHT genes,predominantly methyl jasmonate-(304)and abscisic acid(ABA)-responsive elements(248).Under low phosphorus stress,PHT gene expression exhibited family-and tissue-specific patterns.In roots,the expression level of PbPHT3.7 in the"Jing'an"family increased 11-fold,and expression level of PbPHT5.1 in the"Yifeng"family increased 4-fold.The expression divergence of PbPHT3.21 in stems and leaves was observed across families.[Conclusion]The P.bournei PHT family collaboratively regulates low phosphorus stress adaptation through cis-element diversity and family-specific expression patterns.This study identifies key candidate genes for breeding phosphorus-efficient P.bournei cultivars,and also offers new insights into phosphorus signaling networks in Lauraceae plants.