The apple MdGA2ox7 modulates the balance between growth and stress tolerance in an anthocyanin-dependent manner

Rui Yan; Tianle Zhang; Yuan Wang; Wenxiu Wang; Rahat Sharif; Jiale Liu; Qinglong Dong; Haoan Luan; Xuemei Zhang; Han Li; Suping Guo; Guohui Qi; Peng Jia

doi:10.1016/j.plaphy.2024.108707

The apple MdGA2ox7 modulates the balance between growth and stress tolerance in an anthocyanin-dependent manner

Plant Physiol Biochem. 2024 May 8:212:108707. doi: 10.1016/j.plaphy.2024.108707. Online ahead of print.

Authors

Rui Yan¹, Tianle Zhang¹, Yuan Wang², Wenxiu Wang¹, Rahat Sharif³, Jiale Liu¹, Qinglong Dong¹, Haoan Luan¹, Xuemei Zhang¹, Han Li¹, Suping Guo¹, Guohui Qi⁴, Peng Jia⁵

Affiliations

¹ College of Forestry, Hebei Agricultural University, Baoding, 071000, China.
² State Key Laboratory of North China Crop Improvement and Regulation, Hebei Agricultural University, Baoding, 071000, China.
³ Department of Horticulture, School of Horticulture and Landscape, Yangzhou University, Yangzhou, 225009, China.
⁴ College of Forestry, Hebei Agricultural University, Baoding, 071000, China. Electronic address: bdqgh@hebau.edu.cn.
⁵ College of Forestry, Hebei Agricultural University, Baoding, 071000, China. Electronic address: jiapeng@hebau.edu.cn.

PMID: 38763002
DOI: 10.1016/j.plaphy.2024.108707

Abstract

Apple (Malus domestica Borkh.) is a widely cultivated fruit crop worldwide but often suffers from abiotic stresses such as salt and cold. Gibberellic acid (GA) plays a pivotal in controlling plant development, environmental adaptability, and secondary metabolism. The GA2-oxidase (GA2ox) is responsible for the deactivation of bioactive GA. In this study, seventeen GA2-oxidase genes were identified in the apple genome, and these members could be clustered into four clades based on phylogenetic relationships and conserved domain structures. MdGA2ox7 exhibited robust expression across various tissues, responded to cold and salt treatments, and was triggered in apple fruit peels via light-induced anthocyanin accumulation. Subcellular localization prediction and experiments confirmed that MdGA2ox7 was located in the cytoplasm. Overexpression of MdGA2ox7 in Arabidopsis caused a lower level of active GA and led to GA-deficient phenotypes, such as dwarfism and delayed flowering. MdGA2ox7 alleviated cold and salt stress damage in both Arabidopsis and apple in concert with melatonin (MT). Additionally, MdGA2ox7 enhanced anthocyanin biosynthesis in apple calli and activated genes involved in anthocyanin synthesis. These findings provide new insights into the functions of apple GA2ox in regulating development, stress tolerance, and secondary metabolism.

Keywords: Abiotic stress; Anthocyanins; Apple; GA2ox7.