Shengming Yang1,2,3, Megan Overlander4, Jason Fiedler4,5. 1. USDA-ARS Cereals Research Unit, Edward T. Schafer Agriculture Research Center, Fargo, ND, 58102, USA. Shengming.Yang@usda.gov. 2. Department of Plant Sciences, North Dakota State University, Fargo, ND, 58102, USA. Shengming.Yang@usda.gov. 3. Department of Plant Pathology, North Dakota State University, Fargo, ND, 58102, USA. Shengming.Yang@usda.gov. 4. USDA-ARS Cereals Research Unit, Edward T. Schafer Agriculture Research Center, Fargo, ND, 58102, USA. 5. Department of Plant Sciences, North Dakota State University, Fargo, ND, 58102, USA.
Abstract
BACKGROUND: Providing the photosynthesis factory for plants, chloroplasts are critical for crop biomass and economic yield. However, chloroplast development is a complicated process, coordinated by the cross-communication between the nucleus and plastids, and the underlying biogenesis mechanism has not been fully revealed. Variegation mutants have provided ideal models to identify genes or factors involved in chloroplast development. Well-developed chloroplasts are present in the green tissue areas, while the white areas contain undifferentiated plastids that are deficient in chlorophyll. Unlike albino plants, variegation mutants survive to maturity and enable investigation into the signaling pathways underlying chloroplast biogenesis. The allelic variegated mutants in barley, grandpa 1 (gpa1), have long been identified but have not been genetically characterized. RESULTS: We characterized and genetically analyzed the grandpa1.a (gpa1.a) mutant. The chloroplast ultrastructure was evaluated using transmission electron microscopy (TEM), and it was confirmed that chloroplast biogenesis was disrupted in the white sections of gpa1.a. To determine the precise position of Gpa1, a high-resolution genetic map was constructed. Segregating individuals were genotyped with the barley 50 k iSelect SNP Array, and the linked SNPs were converted to PCR-based markers for genetic mapping. The Gpa1 gene was mapped to chromosome 2H within a gene cluster functionally related to photosynthesis or chloroplast differentiation. In the variegated gpa1.a mutant, we identified a large deletion in this gene cluster that eliminates a putative plastid terminal oxidase (PTOX). CONCLUSIONS: Here we characterized and genetically mapped the gpa1.a mutation causing a variegation phenotype in barley. The PTOX-encoding gene in the delimited region is a promising candidate for Gpa1. Therefore, the present study provides a foundation for the cloning of Gpa1, which will elevate our understanding of the molecular mechanisms underlying chloroplast biogenesis, particularly in monocot plants.
BACKGROUND: Providing the photosynthesis factory for plants, chloroplasts are critical for crop biomass and economic yield. However, chloroplast development is a complicated process, coordinated by the cross-communication between the nucleus and plastids, and the underlying biogenesis mechanism has not been fully revealed. Variegation mutants have provided ideal models to identify genes or factors involved in chloroplast development. Well-developed chloroplasts are present in the green tissue areas, while the white areas contain undifferentiated plastids that are deficient in chlorophyll. Unlike albino plants, variegation mutants survive to maturity and enable investigation into the signaling pathways underlying chloroplast biogenesis. The allelic variegated mutants in barley, grandpa 1 (gpa1), have long been identified but have not been genetically characterized. RESULTS: We characterized and genetically analyzed the grandpa1.a (gpa1.a) mutant. The chloroplast ultrastructure was evaluated using transmission electron microscopy (TEM), and it was confirmed that chloroplast biogenesis was disrupted in the white sections of gpa1.a. To determine the precise position of Gpa1, a high-resolution genetic map was constructed. Segregating individuals were genotyped with the barley 50 k iSelect SNP Array, and the linked SNPs were converted to PCR-based markers for genetic mapping. The Gpa1 gene was mapped to chromosome 2H within a gene cluster functionally related to photosynthesis or chloroplast differentiation. In the variegated gpa1.a mutant, we identified a large deletion in this gene cluster that eliminates a putative plastid terminal oxidase (PTOX). CONCLUSIONS: Here we characterized and genetically mapped the gpa1.a mutation causing a variegation phenotype in barley. The PTOX-encoding gene in the delimited region is a promising candidate for Gpa1. Therefore, the present study provides a foundation for the cloning of Gpa1, which will elevate our understanding of the molecular mechanisms underlying chloroplast biogenesis, particularly in monocot plants.
Authors: P Carol; D Stevenson; C Bisanz; J Breitenbach; G Sandmann; R Mache; G Coupland; M Kuntz Journal: Plant Cell Date: 1999-01 Impact factor: 11.277
Authors: Sebastian Beier; Axel Himmelbach; Christian Colmsee; Xiao-Qi Zhang; Roberto A Barrero; Qisen Zhang; Lin Li; Micha Bayer; Daniel Bolser; Stefan Taudien; Marco Groth; Marius Felder; Alex Hastie; Hana Šimková; Helena Staňková; Jan Vrána; Saki Chan; María Muñoz-Amatriaín; Rachid Ounit; Steve Wanamaker; Thomas Schmutzer; Lala Aliyeva-Schnorr; Stefano Grasso; Jaakko Tanskanen; Dharanya Sampath; Darren Heavens; Sujie Cao; Brett Chapman; Fei Dai; Yong Han; Hua Li; Xuan Li; Chongyun Lin; John K McCooke; Cong Tan; Songbo Wang; Shuya Yin; Gaofeng Zhou; Jesse A Poland; Matthew I Bellgard; Andreas Houben; Jaroslav Doležel; Sarah Ayling; Stefano Lonardi; Peter Langridge; Gary J Muehlbauer; Paul Kersey; Matthew D Clark; Mario Caccamo; Alan H Schulman; Matthias Platzer; Timothy J Close; Mats Hansson; Guoping Zhang; Ilka Braumann; Chengdao Li; Robbie Waugh; Uwe Scholz; Nils Stein; Martin Mascher Journal: Sci Data Date: 2017-04-27 Impact factor: 6.444