过氧化氢调控马尾松幼苗“冬季变红”过程中花色苷的积累

The mechanism underlying winter reddening in evergreen conifers differs from that of deciduous trees,yet a systematic understanding of the winter reddening mechanism in evergreen conifers is lacking.In this study,we analyzed the physiological characteristics and transcriptome sequencing of Pinus massoniana Lamb.seedlings at different stages of winter reddening,from non-red(PT1)to partially red(PT2)and fully red(PT3).Physiological analysis indicates that the accumulation of anthocyanins is the direct factor leading to the red coloration in the seedlings during winter,while hydrogen peroxide(H2O2)serves as the primary substance inducing the accumulation of anthocyanins.Furthermore,the increase in H2O2 levels also triggers the accumulation of soluble sugars and fructose,thereby inhibiting the increase in starch and chlorophyll content.Key structural genes involved in anthocyanin biosynthesis were identified,including phenylalanine ammonia-lyase(PAL),chalcone synthase(CHS),flavanone 3-hydroxylase(F3H),flavonoid 3'-hydroxylase(F3'H),flavonoid 3',5'-hydroxylase(F3'5'H),dihydroflavonol 4-reductase(DFR),and anthocyanidin synthase(ANS).Analysis of the differentially expressed genes(DEGs)and transcription factors(TFs)indicated that H2O2 can influence anthocyanin biosynthesis by regulating the expression of transcription factor families such as bHLH,MYB,and mTERF,as well as genes related to anthocyanin biosynthesis.These findings provide fundamental data for further investigation into the molecular mechanisms underlying winter reddening in evergreen conifers.