Ectopic expression of Kip-related proteins restrains root-knot nematode-feeding...

• Author(s): Vieira, Paulo ; Escudero, Carmen ; Rodiuc, Natalia ; Boruc, Joana ; Russinova, Eugenia ; Glab, Nathalie ; Mota, Manuel ; Veylder, Lieven ; Abad, Pierre ; Engler, Gilbert ; Almeida Engler, Janice
• Date: 2013
• Persistent ID: http://hdl.handle.net/10174/10260
• Origin: Repositório Científico da Universidade de Évora
• Subject(s): Arabidopsis roots, cell cycle; Meloidogyne
• Document Type: Article
• Language: English

Description

The development of nematode feeding sites induced by root-knot nematodes involves the synchronized activation of cell cycle processes such as acytokinetic mitoses and DNA amplification. A number of key cell cycle genes are reported to be critical for nematode feeding site development. However, it remains unknown whether plant cyclin-dependent kinase (CDK) inhibitors such as the Arabidopsis interactor/inhibitor of CDK (ICK)/Kip-related protein (KRP) family are involved in nematode feeding site development. This study demonstrates the involvement of Arabidopsis ICK2/KRP2 and ICK1/KRP1 in the control of mitosis to endoreduplication in galls induced by the root-knot nematode Meloidogyne incognita. ! Using ICK/KRP promoter-GUS fusions and mRNA in situ hybridizations, we showed that ICK2/KRP2, ICK3/KRP5 and ICK4/KRP6 are expressed in galls after nematode infection. Loss-of-function mutants have minor effects on gall development and nematode reproduction. Conversely, overexpression of both ICK1/KRP1 and ICK2/KRP2 impaired mitosis in giant cells and blocked neighboring cell proliferation, resulting in a drastic reduction of gall size. ! Studying the dynamics of protein expression demonstrated that protein levels of ICK2/ KRP2 are tightly regulated during giant cell development and reliant on the presence of the nematode. ! This work demonstrates that impeding cell cycle progression by means of ICK1/KRP1 and ICK2/KRP2 overexpression severely restricts gall development, leading to a marked limitation of root-knot nematode development and reduced numbers of offspring