title: The ZmRCP-1 promoter of maize provides root tip specific expression of transgenes in plantain.
abstract: BACKGROUND
  Bananas and plantains (Musa spp.) provide 25 % of the food energy requirements for more than 100 million people in Africa. Plant parasitic nematodes cause severe losses to the crop due to lack of control options. The sterile nature of Musa spp. hampers conventional breeding but makes the crop suitable for genetic engineering. A constitutively expressed synthetic peptide in transgenic plantain has provided resistance against nematodes. Previous work with the peptide in potato plants indicates that targeting expression to the root tip improves the efficacy of the defence mechanism. However, a promoter that will provide root tip specific expression of transgenes in a monocot plant, such as plantain, is not currently available. Here, we report the cloning and evaluation of the maize root cap-specific protein-1 (ZmRCP-1) promoter for root tip targeted expression of transgenes that provide a defence against plant parasitic nematodes in transgenic plantain.
  
  
  RESULTS
  Our findings indicate that the maize ZmRCP-1 promoter delivers expression of β-glucuronidase (gusA) gene in roots but not in leaves of transgenic plantains. In mature old roots, expression of gusA gene driven by ZmRCP-1 becomes limited to the root cap. Invasion by the nematode Radopholus similis does not modify Root Cap-specific Protein-1 promoter activity.
  
  
  CONCLUSIONS
  Root cap-specific protein-1 promoter from maize can provide targeted expression of transgene for nematode resistance in transgenic plantain.
authors.affiliation: International Institute of Tropical Agriculture (IITA), P.O. Box 7878, Kampala, Uganda ; Biotechnology and Biochemistry Department, Kenyatta University, P.O. Box 43844, Nairobi, Kenya.
authors.forename: Stephen O
authors.initials: SO
authors.lastname: Onyango
authors.affiliation: Centre for Plant Sciences, University of Leeds, Leeds, LS2 9JT UK.
authors.forename: Hugh
authors.initials: H
authors.lastname: Roderick
authors.affiliation: International Institute of Tropical Agriculture (IITA), P.O. Box 7878, Kampala, Uganda.
authors.forename: Jaindra N
authors.initials: JN
authors.lastname: Tripathi
authors.affiliation: Centre for Plant Sciences, University of Leeds, Leeds, LS2 9JT UK.
authors.forename: Richard
authors.initials: R
authors.lastname: Collins
authors.affiliation: Centre for Plant Sciences, University of Leeds, Leeds, LS2 9JT UK.
authors.forename: Howard J
authors.initials: HJ
authors.lastname: Atkinson
authors.affiliation: Biotechnology and Biochemistry Department, Kenyatta University, P.O. Box 43844, Nairobi, Kenya.
authors.forename: Richard O
authors.initials: RO
authors.lastname: Oduor
authors.affiliation: International Institute of Tropical Agriculture (IITA), P.O. Box 7878, Kampala, Uganda.
authors.forename: Leena
authors.initials: L
authors.lastname: Tripathi
keywords: Nematode invasion; Plantain; Root specific promoter; Transgenic defence; β-glucuronidase