Transgenic Sweet Orange (Citrus sinensis L. Osbeck) Expressing the attacin A Gene for Resistance to Xanthomonas citri subsp citri


Autoria(s): CARDOSO, Suane Coutinho; BARBOSA-MENDES, Janaynna Magalhaes; BOSCARIOL-CAMARGO, Raquel Luciana; CHRISTIANO, Rock Seille Carlos; BERGAMIN FILHO, Armando; VIEIRA, Maria Lucia Carneiro; MENDES, Beatriz Madalena Januzzi; MOURAO FILHO, Francisco de Assis Alves
Contribuinte(s)

UNIVERSIDADE DE SÃO PAULO

Data(s)

18/10/2012

18/10/2012

2010

Resumo

Genetic transformation with genes that code for antimicrobial peptides has been an important strategy used to control bacterial diseases in fruit crops, including apples, pears, and citrus. Asian citrus canker (ACC) caused by Xanthomonas citri subsp. citri Schaad et al. (Xcc) is a very destructive disease, which affects the citrus industry in most citrus-producing areas of the world. Here, we report the production of genetically transformed Natal, Pera, and Valencia sweet orange cultivars (Citrus sinensis L. Osbeck) with the insect-derived attacin A (attA) gene and the evaluation of the transgenic plants for resistance to Xcc. Agrobacterium tumefaciens Smith and Towns-mediated genetic transformation experiments involving these cultivars led to the regeneration of 23 different lines. Genetically transformed plants were identified by polymerase chain reaction, and transgene integration was confirmed by Southern blot analyses. Transcription of attA gene was detected by Northern blot analysis in all plants, except for one Natal sweet orange transformation event. Transgenic lines were multiplied by grafting onto Rangpur lime rootstock plants (Citrus limonia Osbeck) and spray-inoculated with an Xcc suspension (10(6) cfu mL(-1)). Experiments were repeated three times in a completely randomized design with seven to ten replicates. Disease severity was determined in all transgenic lines and in the control (non-transgenic) plants 30 days after inoculation. Four transgenic lines of Valencia sweet orange showed a significant reduction in disease severity caused by Xcc. These reductions ranged from 58.3% to 77.8%, corresponding to only 0.16-0.30% of leaf diseased area as opposed to 0.72% on control plants. One transgenic line of Natal sweet orange was significantly more resistant to Xcc, with a reduction of 45.2% comparing to the control plants, with only 0.14% of leaf diseased area. Genetically transformed Pera sweet orange plants expressing attA gene did not show a significant enhanced resistance to Xcc, probably due to its genetic background, which is naturally more resistant to this pathogen. The potential effect of attacin A antimicrobial peptide to control ACC may be related to the genetic background of each sweet orange cultivar regarding their natural resistance to the pathogen.

Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)

Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)

Fundo de Defesa da Citricultura (Fundecitrus)

Identificador

PLANT MOLECULAR BIOLOGY REPORTER, v.28, n.2, p.185-192, 2010

0735-9640

http://producao.usp.br/handle/BDPI/19202

10.1007/s11105-009-0141-0

http://dx.doi.org/10.1007/s11105-009-0141-0

Idioma(s)

eng

Publicador

SPRINGER

Relação

Plant Molecular Biology Reporter

Direitos

restrictedAccess

Copyright SPRINGER

Palavras-Chave #Agrobacterium tumefaciens #Antimicrobial peptide #Asian citrus canker #Disease resistance #Genetic improvement #Transformation #AXONOPODIS PV. CITRI #COAT PROTEIN GENE #SOMATIC HYBRIDIZATION #HYALOPHORA-CECROPIA #TRISTEZA-VIRUS #PHYTOPHTHORA-NICOTIANAE #ENHANCED RESISTANCE #ERWINIA-AMYLOVORA #OUTER-MEMBRANE #FIRE BLIGHT #Biochemical Research Methods #Plant Sciences
Tipo

article

original article

publishedVersion