杧果铁还原酶(FRO)编码基因的鉴定与表达模式分析OA北大核心CSTPCD

Iron(Fe)is one of the essential trace mineral elements in plants to maintain normal growth and development that plays an important role in various life processes.Researches towards molecular mechanism of Fe uptake,transport and distribution are mainly focused on the annual model plants.Biological functions of genes towards Fe uptake and transport in fruit trees are still unknown.In this study,11 ferric reduction oxidase encoding genes(FROs)were isolated and identified from diploid mango Guire 82,named by MiFRO1-MiFRO11.All mango FRO had ten typical motifs ex-cept for MiFRO1 lacking Motif2-Motif5.All mango FRO possessed similar tertiary structure,with the exception that MiFRO3 exhibited distinct tertiary structure.The amino acid sequences of FRO from 11 plants shared an overall identity of 42.07% ,while mango FRO shared an overall identity of 62.43% .Phylogenetic tree analysis showed that mango FRO were prone to be closely clustered together lonely,which was far away from the homologs of the other ten plants in genetic distance.Quantitative real-time PCR(qRT-PCR)analysis showed that MiFRO3 was the most abundant ex-pressed gene during different parts of Guire 82 mango on the whole.In particular,MiFRO4,MiFRO5,MiFRO8 and MiFRO11 were highly expressed in the leaves of both mature trees and grafted seedlings.MiFRO6 and MiFRO7 were highly expressed in phloem or stem,MiFRO1 and MiFRO10 were highly expressed in young fruits,MiFRO2 and Mi-FRO9 were highly expressed in seedling roots,while MiFRO3 was highly expressed in full bloom flowers.In addition,expression of FRO in mango roots were mainly induced under iron depletion and NaCl stress,respectively,while Mi-FRO3,MiFRO5 and MiFRO8 were significantly reduced under iron toxicity.Expression of MiFRO2,MiFRO5 and Mi-FRO7 were increased under ABA treatment,and MiFRO1 and MiFRO5 were enhanced under PEG treatment.Expression of MiFRO2,MiFRO6 and MiFRO7 were decreased under low temperature(4℃ ).However,FRO changed little under heat stress(45℃ )in mango roots.This study would provide gene resources to elucidate the molecular mechanisms of Fe uptake and transport in mango,and lay a theoretical foundation to reveal Fe nutrition and high utilization in tropical fruit crops.