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Zou Y, Huang Y, Zhang D, Chen H, Liang Y, Hao M, Yin Y. Molecular Mechanisms of Chlorophyll Deficiency in Ilex × attenuata 'Sunny Foster' Mutant. PLANTS (BASEL, SWITZERLAND) 2024; 13:1284. [PMID: 38794356 PMCID: PMC11124982 DOI: 10.3390/plants13101284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 05/01/2024] [Accepted: 05/04/2024] [Indexed: 05/26/2024]
Abstract
Ilex × attenuata 'Sunny Foster' represents a yellow leaf mutant originating from I. × attenuata 'Foster#2', a popular ornamental woody cultivar. However, the molecular mechanisms underlying this leaf color mutation remain unclear. Using a comprehensive approach encompassing cytological, physiological, and transcriptomic methodologies, notable distinctions were discerned between the mutant specimen and its wild type. The mutant phenotype displayed aberrant chloroplast morphology, diminished chlorophyll content, heightened carotenoid/chlorophyll ratios, and a decelerated rate of plant development. Transcriptome analysis identified differentially expressed genes (DEGs) related to chlorophyll metabolism, carotenoid biosynthesis and photosynthesis. The up-regulation of CHLD and CHLI subunits leads to decreased magnesium chelatase activity, while the up-regulation of COX10 increases heme biosynthesis-both impair chlorophyll synthesis. Conversely, the down-regulation of HEMD hindered chlorophyll synthesis, and the up-regulation of SGR enhanced chlorophyll degradation, resulting in reduced chlorophyll content. Additionally, genes linked to carotenoid biosynthesis, flavonoid metabolism, and photosynthesis were significantly down-regulated. We also identified 311 putative differentially expressed transcription factors, including bHLHs and GLKs. These findings shed light on the molecular mechanisms underlying leaf color mutation in I. × attenuata 'Sunny Foster' and provide a substantial gene reservoir for enhancing leaf color through breeding techniques.
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Affiliation(s)
- Yiping Zou
- College of Forestry, Nanjing Forestry University, Nanjing 210037, China; (Y.Z.)
- Institute of Botany, Jiangsu Province and Chinese Academy of Sciences (Nanjing Botanical Garden Mem. Sun Yat-Sen), Nanjing 210014, China
- Jiangsu Qinghao Landscape Horticulture Co., Ltd., Nanjing 211225, China
| | - Yajian Huang
- College of Forestry, Nanjing Forestry University, Nanjing 210037, China; (Y.Z.)
| | - Donglin Zhang
- Department of Horticulture, University of Georgia, Athens, GA 30602, USA
| | - Hong Chen
- Institute of Botany, Jiangsu Province and Chinese Academy of Sciences (Nanjing Botanical Garden Mem. Sun Yat-Sen), Nanjing 210014, China
| | - Youwang Liang
- College of Forestry, Nanjing Forestry University, Nanjing 210037, China; (Y.Z.)
| | - Mingzhuo Hao
- College of Forestry, Nanjing Forestry University, Nanjing 210037, China; (Y.Z.)
- Jiangsu Qinghao Landscape Horticulture Co., Ltd., Nanjing 211225, China
| | - Yunlong Yin
- College of Forestry, Nanjing Forestry University, Nanjing 210037, China; (Y.Z.)
- Institute of Botany, Jiangsu Province and Chinese Academy of Sciences (Nanjing Botanical Garden Mem. Sun Yat-Sen), Nanjing 210014, China
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Zhang X, Zhao Z, Zhang M, Wang J, Cheng T, Zhang Q, Pan H. FsHemF is involved in the formation of yellow Forsythia leaves by regulating chlorophyll synthesis in response to light intensity. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2023; 200:107746. [PMID: 37210861 DOI: 10.1016/j.plaphy.2023.107746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 04/21/2023] [Accepted: 05/04/2023] [Indexed: 05/23/2023]
Abstract
The leaves of Forsythia koreana 'Suwon Gold' are yellow under natural light condition and can revert to green when the light intensity is reduced. To understand the molecular mechanism of leaf color changes in response to light intensity, we compared the chlorophyll content and precursor content between yellow- and green-leaf Forsythia under shade and light-recovery conditions. We identified the conversion of coproporphyrin III (Coprogen III) to protoporphyrin IX (Proto IX) as the primary rate-limiting step of chlorophyll biosynthesis in yellow-leaf Forsythia. Further analysis of the activity of the enzymes that catalyze this step and the expression pattern of the chlorophyll biosynthesis-related genes under different light intensities revealed that the negatively regulated expression of FsHemF by light intensity was the major cause affecting the leaf color change in response to light intensity in yellow-leaf Forsythia. To further understand the cause of differential expression pattern of FsHemF in yellow- and green-leaf lines, we compared the coding sequence and promoter sequence of FsHemF between yellow- and green-leaf Forsythia. We found that one G-box light-responsive cis-element was absent in the promoter region of green-leaf lines. To investigate the functional role of FsHemF, we performed virus-induced gene silencing (VIGS) of FsHemF in green-leaf Forsythia, which leads to yellowing leaf veins, decreased chlorophyll b content, and inhibition of chlorophyll biosynthesis. The results will assist in elucidating the mechanism of yellow-leaf Forsythia in response to light intensity.
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Affiliation(s)
- Xiaolu Zhang
- Beijing Key Laboratory of Ornamental Plants Germplasm Innovation & Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment, College of Landscape Architecture, Beijing Forestry University, Beijing, 100083, China
| | - Zhengtian Zhao
- Beijing Key Laboratory of Ornamental Plants Germplasm Innovation & Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment, College of Landscape Architecture, Beijing Forestry University, Beijing, 100083, China
| | - Man Zhang
- Beijing Key Laboratory of Ornamental Plants Germplasm Innovation & Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment, College of Landscape Architecture, Beijing Forestry University, Beijing, 100083, China
| | - Jia Wang
- Beijing Key Laboratory of Ornamental Plants Germplasm Innovation & Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment, College of Landscape Architecture, Beijing Forestry University, Beijing, 100083, China
| | - Tangren Cheng
- Beijing Key Laboratory of Ornamental Plants Germplasm Innovation & Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment, College of Landscape Architecture, Beijing Forestry University, Beijing, 100083, China
| | - Qixiang Zhang
- Beijing Key Laboratory of Ornamental Plants Germplasm Innovation & Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment, College of Landscape Architecture, Beijing Forestry University, Beijing, 100083, China
| | - Huitang Pan
- Beijing Key Laboratory of Ornamental Plants Germplasm Innovation & Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment, College of Landscape Architecture, Beijing Forestry University, Beijing, 100083, China.
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