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Wang Y, Sun J, Wang N, Xu H, Qu C, Jiang S, Fang H, Su M, Zhang Z, Chen X. MdMYBL2 helps regulate cytokinin-induced anthocyanin biosynthesis in red-fleshed apple (Malus sieversii f. niedzwetzkyana) callus. FUNCTIONAL PLANT BIOLOGY : FPB 2019; 46:187-196. [PMID: 32172760 DOI: 10.1071/fp17216] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 09/20/2018] [Indexed: 06/10/2023]
Abstract
Anthocyanin biosynthesis is induced by cytokinins, and is regulated by MYB transcription factors. However, the underlying molecular mechanisms have not been fully characterised. In the present study, red-fleshed apple callus were induced from the leaves of an R6/R6 homozygous line, which was the hybrid offspring of Malus sieversii f. niedzwetzkyana and 'Fuji'. We analysed the callus anthocyanin contents in response to different cytokinin concentrations. We observed that cytokinin treatments upregulated the expression of anthocyanin structural genes MdDFR and MdUFGT and transcription factor genes MdMYB10 and MdbHLH3. Additionally, the expression of MdMYBL2, which encodes the bHLH and EAR motifs, was inhibited by cytokinin treatments. The MdMYBL2-overexpressing callus had lower anthocyanin contents than the wild-type controls. We noted that the expression levels of anthocyanin biosynthesis structural genes MdDFR and MdUFGT and transcription factor genes MdMYB10 and MdbHLH3 were strongly suppressed in the transgenic callus. Subsequent yeast two-hybrid, bimolecular fluorescence complementation, and pull-down assays indicated that MdMYBL2 interacts with MdbHLH3, which may influence the expression of anthocyanin biosynthesis-related genes. Our findings may provide new insights into how MYB transcription factors influence the cytokinin-regulated anthocyanin biosynthesis in red-fleshed apples.
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Affiliation(s)
- Yicheng Wang
- State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong, China
| | - Jingjing Sun
- College of Forestry, Shandong Agricultural University, Tai-An, Shandong, China
| | - Nan Wang
- State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong, China
| | - Haifeng Xu
- State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong, China
| | - Changzhi Qu
- State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong, China
| | - Shenghui Jiang
- State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong, China
| | - Hongcheng Fang
- State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong, China
| | - Mengyu Su
- State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong, China
| | - Zongying Zhang
- State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong, China
| | - Xuesen Chen
- State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong, China
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Alferez F, Zhong GY, Burns JK. A citrus abscission agent induces anoxia- and senescence-related gene expression in Arabidopsis. JOURNAL OF EXPERIMENTAL BOTANY 2007; 58:2451-62. [PMID: 17556766 DOI: 10.1093/jxb/erm111] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The mechanisms of negative effects of 5-chloro-3-methyl-4-nitro-1H-pyrazole (CMNP), a pyrazole-derived plant growth regulator used as a citrus abscission agent, were explored in Arabidopsis by integrating transcriptomic, physiological, and ultrastructural analyses. CMNP promoted starch degradation and senescence-related symptoms, such as chloroplast membrane disruption, electrolyte leakage, and decreased chlorophyll and protein content. Symptoms of plant decline were evident 12 h after CMNP treatment. Microarray analysis revealed that CMNP influenced genes associated with stress, including those related to anoxia, senescence, and detoxification. Sucrose treatment arrested CMNP-induced plant decline. The results demonstrate that the plant response to CMNP shares common elements with various stresses and senescence at physiological and molecular levels.
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Affiliation(s)
- Fernando Alferez
- Horticultural Sciences Department, University of Florida, IFAS, Citrus Research and Education Center, Lake Alfred, FL 33850, USA
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Baba K, Nakano T, Yamagishi K, Yoshida S. Involvement of a nuclear-encoded basic helix-loop-helix protein in transcription of the light-responsive promoter of psbD. PLANT PHYSIOLOGY 2001; 125:595-603. [PMID: 11161017 PMCID: PMC64861 DOI: 10.1104/pp.125.2.595] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2000] [Revised: 06/18/2000] [Accepted: 10/03/2000] [Indexed: 05/20/2023]
Abstract
In the chloroplast psbD light-responsive promoter (LRP), a highly conserved sequence exists upstream from the bacterial -10/-35 elements. Multiple sequence-specific DNA binding proteins are predicted to bind to the conserved sequence as transcription factors. Using yeast one-hybrid screening of an Arabidopsis cDNA library, a possible DNA binding protein of the psbD LRP upstream sequence was identified. The protein, designated PTF1, is a novel protein of 355 amino acids (estimated molecular weight of 39.6) that contains a basic helix-loop-helix DNA binding motif in the predicted N-terminal region of the mature protein. Transient expression assay of PTF1-GFP fusion protein showed that PTF1 was localized in chloroplasts. Using the modified DNA sequence in the one-hybrid system, the ACC repeat was shown to be essential for PTF1 binding. The rate of psbD LRP mRNA accumulation was reduced in a T-DNA-inserted Arabidopsis ptf1 mutant. Compared with wild-type plants, the mutant had pale green cotyledons and its growth was inhibited under short-day conditions. These results suggest that PTF1 is a trans-acting factor of the psbD LRP.
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Affiliation(s)
- K Baba
- RIKEN, The Institute of Physical and Chemical Research, Wako, Saitama 351-0198, Japan.
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