title: Comparative Proteomic and Physiological Analysis Reveals the Variation Mechanisms of Leaf Coloration and Carbon Fixation in a Xantha Mutant of Ginkgo biloba L.
abstract: Yellow-green leaf mutants are common in higher plants, and these non-lethal chlorophyll-deficient mutants are ideal materials for research on photosynthesis and plant development. A novel xantha mutant ofGinkgo bilobadisplaying yellow-colour leaves (YL) and green-colour leaves (GL) was identified in this study. The chlorophyll content of YL was remarkably lower than that in GL. The chloroplast ultrastructure revealed that YL had less dense thylakoid lamellae, a looser structure and fewer starch grains than GL. Analysis of the photosynthetic characteristics revealed that YL had decreased photosynthetic activity with significantly high nonphotochemical quenching. To explain these phenomena, we analysed the proteomic differences in leaves and chloroplasts between YL and GL of ginkgo using two-dimensional gel electrophoresis (2-DE) coupled with MALDI-TOF/TOF MS. In total, 89 differential proteins were successfully identified, 82 of which were assigned functions in nine metabolic pathways and cellular processes. Among them, proteins involved in photosynthesis, carbon fixation in photosynthetic organisms, carbohydrate/energy metabolism, amino acid metabolism, and protein metabolism were greatly enriched, indicating a good correlation between differentially accumulated proteins and physiological changes in leaves. The identifications of these differentially accumulated proteins indicates the presence of a specific different metabolic network in YL and suggests that YL possess slower chloroplast development, weaker photosynthesis, and a less abundant energy supply than GL. These studies provide insights into the mechanism of molecular regulation of leaf colour variation in YL mutants.
authors: Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China. xliu25@lakeheadu.ca.
authors: Xinliang
authors: X
authors: Liu
authors: Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China. youeryuww@163.com.
authors: Wanwen
authors: W
authors: Yu
authors: Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China. gbwang@njfu.edu.cn.
authors: Guibin
authors: G
authors: Wang
authors: Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China. fuliangcaonjfu@163.com.
authors: Fuliang
authors: F
authors: Cao
authors: Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China. caijinfeng1984@126.com.|The Jiangsu Provincial Platform for Conservation and Utilization of Agricultural Germplasm, Nanjing 210037, China. caijinfeng1984@126.com.
authors: Jinfeng
authors: J
authors: Cai
authors: Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing 210037, China. wanghuanlis@163.com.
authors: Huanli
authors: H
authors: Wang
mesh_terms: D057486:Carbon Cycle / Q000235:genetics*; D002734:Chlorophyll / Q000096:biosynthesis / Q000235:genetics; D002736:Chloroplasts / Q000235:genetics; D015180:Electrophoresis, Gel, Two-Dimensional; D020441:Ginkgo biloba / Q000235:genetics* / Q000254:growth & development; D010788:Photosynthesis / Q000235:genetics*; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development; D010940:Plant Proteins / Q000096:biosynthesis; D020543:Proteome / Q000235:genetics*; D040901:Proteomics / Q000379:methods
chemical_list: D010940:Plant Proteins; D020543:Proteome; D002734:Chlorophyll
keywords: Ginkgo biloba L.; chloroplast; comparative proteomics; photosynthesis; xantha mutant