%0 Journal Article %A ZHOU Shuqian %A CHEN Lu %A CHEN Huiyun %A LI Yongxin %A CHEN Gang %A LU Guoquan %A YANG Huqing %T Bioinformatics and Expression Analysis of Alternative Oxidase Genes in Sweetpotato %D 2022 %R 10.11869/j.issn.100-8551.2022.02.0270 %J Journal of Nuclear Agricultural Sciences %P 270-281 %V 36 %N 2 %X

This study was aimed to identify the members of alternative oxidase (AOX) gene family in sweetpotato [Ipomoea batatas (L.) Lam.], and characterize their expression patterns in response to biotic and abiotic stresses. Based on genome wide screening and gene cloning and sequencing, three members of AOX gene family were obtained from Xinxiang sweetpotato. The gene structure analysis showed that the cDNA of three AOX genes in sweetpotato were 963 bp, 1080 bp and 1032 bp in length, encoded 320, 359 and 343 amino acids, respectively. Three AOX genes all contained 4 exons and 3 introns, and were named as IbAOX1a (GenBank accession number:MT992313), IbAOX1b (GenBank accession number:MT992314) and IbAOX2 (GenBank accession number:MG450566.1), respectively. Protein homology analysis showed that the protein sequences of IbAOX were very conservative at the C-terminus, only minor differences existed at the N-terminus, and there were special Fe-binding conserved domains of EXXH, FXHR and EEE-Y in the sequences. Subcellular localization prediction showed that IbAOX were mainly located in mitochondria. Protein secondary structure prediction showed that the primary secondary structure of the gene family was α-helix, β-turn, extended chain and irregular coils. Real-time fluorescence quantitative PCR (qRT-PCR) analysis showed that the expression of IbAOXs gene was tissue-specific. The transcript level of IbAOX1a in leaves was the highest, while IbAOX1b and IbAOX2 were highly expressed in tuberous roots. The expression of IbAOX1a and IbAOX2 in buds were hardly detected. The expression of IbAOX1a and IbAOX1b in seedlings was stimulated under cold, drought and salt stresses. The transcript level of IbAOX1a was significantly higher than that of IbAOX1b in tuberous roots at 4℃, while the expression IbAOX1b in tuberous roots infected by Fusarium solani was markedly higher than that of IbAOX1a. However, the expression of IbAOX2 in sweetpotato seedlings or tuberous root was not altered under various stresses, showing a constitutive expression pattern. This study provides a theoretical basis for studying the functions of AOX genes and breeding sweetpotato varieties with stress resistances.

%U https://www.hnxb.org.cn/EN/10.11869/j.issn.100-8551.2022.02.0270