Identification of Ascorbate Oxidase Genes and Their Response to Cold Stress in <i>Citrus sinensis</i>
Ascorbate oxidase (AAO) plays an important role in maintaining cellular redox homeostasis, thereby influencing plant growth, development, and responses to both biotic and abiotic stresses. However, there has been no systematic characterization of <i>AAO</i> genes in <i>Citrus</i...
Saved in:
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2024-09-01
|
| Series: | Agriculture |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2077-0472/14/9/1643 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | Ascorbate oxidase (AAO) plays an important role in maintaining cellular redox homeostasis, thereby influencing plant growth, development, and responses to both biotic and abiotic stresses. However, there has been no systematic characterization of <i>AAO</i> genes in <i>Citrus</i>, especially their roles in response to cold stress. In the present study, nine <i>AAO</i> genes were identified in <i>C. sinensis</i> through bioinformatics analyses, exhibiting uneven distribution across four chromosomes. All CsAAOs possessed three conserved domains and were predicted to localize in the apoplast. The <i>CsAAO</i> gene family displayed varied intron–exon patterns. Phylogenetic analysis categorized the <i>CsAAO</i> family into three main clades (Clade A–C), suggesting distinct biological functions. Collinearity and Ka/Ks analysis revealed three duplicate gene pairs within the <i>CsAAO</i> gene family, with all duplicated CsAAOs primarily evolving under purifying selection. Analysis of <i>cis</i>-acting elements showed the presence of multiple hormone response elements and stress response elements within the <i>CsAAO</i> promoters. The computational analysis of microRNA target transcripts suggested that <i>CsAAO9</i> may be a target of csi-miR156. RNA-Seq data demonstrated high expression levels of <i>CsAAOs</i> in roots and young fruits, while qRT-PCR analysis showed significant upregulation of six <i>CsAAOs</i> in response to cold treatment. Furthermore, the activities of CsAAOs exhibited a pattern of initial decrease followed by an increase after exposure to low temperatures. These findings offer important insights into the role of <i>CsAAOs</i> in response to cold stress. Furthermore, <i>AAOs</i> could be target genes for breeding crops with better cold resistance. |
|---|---|
| ISSN: | 2077-0472 |