MdAIL5 overexpression promotes apple adventitious shoot regeneration by regulating hormone signaling and activating the expression of shoot development-related genes

Kai Liu; An Yang; Jiadi Yan; Zhaolin Liang; Gaopeng Yuan; Peihua Cong; Liyi Zhang; Xiaolei Han; Caixia Zhang

doi:10.1093/hr/uhad198

MdAIL5 overexpression promotes apple adventitious shoot regeneration by regulating hormone signaling and activating the expression of shoot development-related genes

Hortic Res. 2023 Oct 10;10(11):uhad198. doi: 10.1093/hr/uhad198. eCollection 2023 Nov.

Authors

Kai Liu^{1

2

3}, An Yang^{1

2}, Jiadi Yan^{1

2}, Zhaolin Liang^{1

2}, Gaopeng Yuan⁴, Peihua Cong^{1

2}, Liyi Zhang^{1

2}, Xiaolei Han^{1

2}, Caixia Zhang^{1

2}

Affiliations

¹ Apple Breeding, Chinese Academy of Agricultural Sciences Research Institute of Pomology, Xingcheng 125100, China.
² Key Laboratory of Horticultural Crops Germplasm Resources Utilization, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Xingcheng 125100, China.
³ Shandong Academy of Grape, Shandong Academy of Agricultural Sciences, Jinan 250100, China.
⁴ Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou 450009, China.

Abstract

Adventitious shoot (AS) regeneration is a significant factor in the genetic transformation of horticultural plants. It is also a noteworthy approach to their vegetative propagation. AS regeneration remains highly dependent on the genotype or maturity of explants. We here found that the AS regeneration abilities of apple leaves were positively correlated with MdAIL5 expression. MdAIL5 overexpression dramatically increased AS regeneration efficiency. Notably, MdAIL5 overexpression could restore the AS formation ability of explants to a certain extent, which was lost with an increase in maturity. Endogenous hormone detection revealed that MdAIL5 overexpression changed the contents of auxin, cytokinin (CK), and other hormones in apple leaves. Transcriptome analysis revealed that many genes related to auxin, CK, and brassinolide signaling pathways were significantly and differentially expressed between MdAIL5-overexpressing transgenic apple and wild-type apple plants. Yeast one-hybrid assays, the electrophoretic mobility shift assay, and the dual-luciferase reporter assay revealed that MdAIL5 directly binds to MdARF9 and MdHB14 promoters and positively affects their expression. We here established a model of MdAIL5 regulating AS formation, which acts as a theoretical basis for facilitating genotype- or explant maturity-independent AS regeneration in the future.