title: The MADS-box gene Agamous-like 11 is essential for seed morphogenesis in grapevine.
abstract: Despite the wide appreciation of seedless grapes, little is known about the molecular mechanisms that drive the stenospermocarpic seedless-type phenotype in grapevine. In order to address the molecular mechanisms that control seedlessness in grapevine, our study aimed to characterize VviAGL11, a class D MADS-box transcription factor gene that has been proposed as the major candidate gene involved in Vitis vinifera seed morphogenesis. VviAGL11 allelic variations in seeded and seedless grapevine cultivars were determined, and its correlations with allele-specific steady-state mRNA levels were investigated. VviAGL11 relative expression was significantly higher in seeds at 2, 4, and 6 weeks after fruit set, whereas in the seedless grape its transcript levels were extremely low in all stages analyzed. In situ hybridization revealed transcript accumulation specifically in the dual endotesta layer of the seeds, which is responsible for elongation and an increase of cell number, a necessary step to determine the lignification and the final seed size. No hybridization signals were visible in the seedless grapevine tissues, and a morphoanatomical analysis showed an apparent loss of identity of the endotesta layer of the seed traces. Ectopic expression of VviAGL11 in the Arabidopsis SEEDSTICK mutant background restored the wild-type phenotype and confirmed the direct role of VviAGL11 in seed morphogenesis, suggesting that depletion of its expression is responsible for the erroneous development of a highly essential seed layer, therefore culminating in the typical apirenic phenotype.
authors.affiliation: Graduate Program in Cell and Molecular Biology, Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Avenida Bento Gonçalves, 9500, Porto Alegre, RS, 91501-970, Brazil.|Centro Nacional de Pesquisa de Uva e Vinho, Empresa Brasileira de Pesquisa Agropecuária, Rua Livramento, 515, Bento Gonçalves, RS, 95701-008, Brazil.
authors.forename: Jaiana
authors.initials: J
authors.lastname: Malabarba
authors.affiliation: Centro Nacional de Pesquisa de Uva e Vinho, Empresa Brasileira de Pesquisa Agropecuária, Rua Livramento, 515, Bento Gonçalves, RS, 95701-008, Brazil.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Buffon
authors.affiliation: Departamento de Botânica, Universidade Federal do Rio Grande do Sul, Avenida Bento Gonçalves, 9500, Porto Alegre, RS, 91501-970, Brazil.
authors.forename: Jorge E A
authors.initials: JEA
authors.lastname: Mariath
authors.affiliation: Departamento de Botânica, Universidade Federal do Rio Grande do Sul, Avenida Bento Gonçalves, 9500, Porto Alegre, RS, 91501-970, Brazil.
authors.forename: Marcos L
authors.initials: ML
authors.lastname: Gaeta
authors.affiliation: Departamento de Biologia Vegetal, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, SP, 13083-862, Brazil.
authors.forename: Marcelo C
authors.initials: MC
authors.lastname: Dornelas
authors.affiliation: Graduate Program in Cell and Molecular Biology, Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Avenida Bento Gonçalves, 9500, Porto Alegre, RS, 91501-970, Brazil.
authors.forename: Márcia
authors.initials: M
authors.lastname: Margis-Pinheiro
authors.affiliation: Graduate Program in Cell and Molecular Biology, Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Avenida Bento Gonçalves, 9500, Porto Alegre, RS, 91501-970, Brazil.
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Pasquali
authors.affiliation: Centro Nacional de Pesquisa de Uva e Vinho, Empresa Brasileira de Pesquisa Agropecuária, Rua Livramento, 515, Bento Gonçalves, RS, 95701-008, Brazil.
authors.forename: Luís F
authors.initials: LF
authors.lastname: Revers
mesh_terms: D018506:Gene Expression Regulation, Plant; D026161:MADS Domain Proteins / Q000235:genetics* / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D012639:Seeds / Q000254:growth & development* / Q000378:metabolism; D017422:Sequence Analysis, DNA; D027843:Vitis / Q000235:genetics* / Q000378:metabolism
chemical_list: D026161:MADS Domain Proteins; D010940:Plant Proteins
keywords: Apireny; Sultanine; VviAGL11.; grapevine; in situ hybridization; seedlessness