title: EjAP2-1, an AP2/ERF gene, is a novel regulator of fruit lignification induced by chilling injury, via interaction with EjMYB transcription factors.
abstract: Lignin biosynthesis is regulated by many transcription factors, such as those of the MYB and NAC families. However, the roles of AP2/ERF transcription factors in lignin biosynthesis have been rarely investigated. Eighteen EjAP2/ERF genes were isolated from loquat fruit (Eriobotrya japonica), which undergoes postharvest lignification during low temperature storage. Among these, expression of EjAP2-1, a transcriptional repressor, was negatively correlated with fruit lignification. The dual-luciferase assay indicated that EjAP2-1 could trans-repress activities of promoters of lignin biosynthesis genes from both Arabidopsis and loquat. However, EjAP2-1 did not interact with the target promoters (Ej4CL1). Yeast two-hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) assays indicated protein-protein interactions between EjAP2-1 and lignin biosynthesis-related EjMYB1 and EjMYB2. Furthermore, repression effects on the Ej4CL1 promoter were observed with the combination of EjAP2-1 and EjMYB1 or EjMYB2, while EjAP2-1 with the EAR motif mutated (mEjAP2-1) lost such repression, although mEjAP2-1 still interacted with EjMYB protein. Based on these results, it is proposed that EjAP2-1 is an indirect transcriptional repressor on lignin biosynthesis, and the repression effects were manifested by EAR motifs and were conducted via protein-protein interaction with EjMYBs.
authors.affiliation: Laboratory of Fruit Quality Biology/The State Agriculture Ministry Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Zhejiang University, Hangzhou, China.
authors.forename: Jiao-Ke
authors.initials: JK
authors.lastname: Zeng
authors.affiliation: Laboratory of Fruit Quality Biology/The State Agriculture Ministry Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Zhejiang University, Hangzhou, China.
authors.forename: Xian
authors.initials: X
authors.lastname: Li
authors.affiliation: Laboratory of Fruit Quality Biology/The State Agriculture Ministry Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Zhejiang University, Hangzhou, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Xu
authors.affiliation: State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources/Guangdong Key Laboratory for Postharvest Science, College of Horticultural Science, South China Agricultural University, Guangzhou, China.
authors.forename: Jian-Ye
authors.initials: JY
authors.lastname: Chen
authors.affiliation: Laboratory of Fruit Quality Biology/The State Agriculture Ministry Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Zhejiang University, Hangzhou, China.
authors.forename: Xue-Ren
authors.initials: XR
authors.lastname: Yin
authors.affiliation: Laboratory of Fruit Quality Biology/The State Agriculture Ministry Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Zhejiang University, Hangzhou, China.|New Zealand Institute for Plant & Food Research Limited, Auckland, New Zealand.
authors.forename: Ian B
authors.initials: IB
authors.lastname: Ferguson
authors.affiliation: Laboratory of Fruit Quality Biology/The State Agriculture Ministry Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Zhejiang University, Hangzhou, China.
authors.forename: Kun-Song
authors.initials: KS
authors.lastname: Chen
mesh_terms: D003080:Cold Temperature / Q000009:adverse effects*; D031983:Eriobotrya / Q000235:genetics* / Q000378:metabolism; D005638:Fruit / Q000235:genetics* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000235:genetics*; D017343:Genes, Plant / Q000235:genetics* / Q000502:physiology; D008031:Lignin / Q000378:metabolism*; D053858:Metabolic Networks and Pathways / Q000235:genetics / Q000502:physiology; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics* / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics* / Q000502:physiology
chemical_list: D010940:Plant Proteins; D014157:Transcription Factors; D008031:Lignin
keywords: AP2-MYB complex; AP2/ERF; chilling injury; lignification; lignin; loquat fruit