Comparative Physio-Biochemical and Transcriptome Analyses Reveal Contrasting Responses to Magnesium Imbalances in Leaves of Mulberry (<i>Morus alba</i> L.) Plants
Yisu Shi,
Xin Jin,
Michael Ackah,
Frank Kwarteng Amoako,
Jianbin Li,
Victor Edem Tsigbey,
Haonan Li,
Zipei Cui,
Longwei Sun,
Chengfeng Zhao,
Weiguo Zhao
Affiliations
Yisu Shi
Jiangsu Key Laboratory of Sericulture Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China
Xin Jin
Jiangsu Key Laboratory of Sericulture Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China
Michael Ackah
Jiangsu Key Laboratory of Sericulture Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China
Frank Kwarteng Amoako
Institute of Plant Nutrition and Soil Science, Kiel University, Hermann-Rodewald-Straße 2, 24118 Kiel, Germany
Jianbin Li
Jiangsu Key Laboratory of Sericulture Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China
Victor Edem Tsigbey
Jiangsu Key Laboratory of Sericulture Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China
Haonan Li
Jiangsu Key Laboratory of Sericulture Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China
Zipei Cui
Jiangsu Key Laboratory of Sericulture Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China
Longwei Sun
Jiangsu Key Laboratory of Sericulture Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China
Chengfeng Zhao
Jiangsu Key Laboratory of Sericulture Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China
Weiguo Zhao
Jiangsu Key Laboratory of Sericulture Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China
Magnesium (Mg) deficiency is a major factor limiting the growth and development of plants. Mulberry (Morus alba L.) is an important fruit tree crop that requires Mg for optimal growth and yield, especially in acid soils. However, the molecular mechanism of Mg stress tolerance in mulberry plants remains unknown. In this study, we used next-generation sequencing technology and biochemical analysis to profile the transcriptome and physiological changes of mulberry leaves under different Mg treatments (deficiency: 0 mM, low: 1 mM, moderate low: 2 mM, sufficiency: 3 mM, toxicity: 6 mM, higher toxicity: 9 mM) as T1, T2, T3, CK, T4, T5 treatments, respectively, for 20 days. The results showed that Mg imbalance altered the antioxidant enzymatic activities, such as catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD), and non-enzymatic, including soluble protein, soluble sugar, malondialdehyde (MDA), and proline (PRO), contents of the plant. The Mg imbalances disrupted the ultrastructures of the vital components of chloroplast and mitochondria relative to the control. The transcriptome data reveal that 11,030 genes were differentially expressed (DEGs). Genes related to the photosynthetic processes (CAB40, CAB7, CAB6A, CAB-151, CAP10A) and chlorophyll degradation (PAO, CHLASE1, SGR) were altered. Antioxidant genes such as PER42, PER21, and PER47 were downregulated, but DFR was upregulated. The carbohydrate metabolism pathway was significantly altered, while those involved in energy metabolism processes were perturbed under high Mg treatment compared with control. We also identified several candidate genes associated with magnesium homeostasis via RT-qPCR validation analysis, which provided valuable information for further functional characterization studies such as promoter activity assay or gene overexpression experiments using transient expression systems.
