- E.R.I.C. Kalkman (1)
- J.A.L. Kan van (1)
- T. Nürnberger (1)
- M. Osés Ruiz (1)
- P. Santhanam (1)
- A. Schouten (1)
- B.P.H.J. Thomma (1)
- B. Uwumukiza (1)
- P. Vredenbregt (1)
Evidence for functional diversification within a fungal NEP1-like protein family
Santhanam, P. ; Esse, H.P. van; Albert, I. ; Faino, L. ; Nürnberger, T. ; Thomma, B.P.H.J. - \ 2013
Molecular Plant-Microbe Interactions 26 (2013)3. - ISSN 0894-0282 - p. 278 - 286.
carotovora subsp carotovora - plant-pathogen interactions - necrosis-inducing activity - chitin-triggered immunity - verticillium-dahliae - mycosphaerella-graminicola - molecular characterization - arabidopsis-thaliana - fusarium-oxysporum - npp1 domain
In this study, we functionally analyzed the gene family encoding necrosis- and ethylene-inducing-like proteins (NLPs) of the vascular wilt pathogen Verticillium dahliae. We show that the composition of the NLP gene family varies little among V. dahliae isolates. The cytotoxic activity of NLP family members of a tomato pathogenic V. dahliae strain was determined, demonstrating that only two of the seven NLPs induced plant cell death. The genes encoding these cytotoxic NLPs were found to be induced in V. dahliae upon colonization of tomato. Interestingly, targeted deletion of either of the two genes in V. dahliae significantly compromised virulence on tomato as well as on Arabidopsis plants, whereas deletion of only one of the two genes affected virulence on N. benthamiana. This could be attributed to differential induction of the two NLP genes in V. dahliae upon N. benthamiana colonization, revealing that the in planta induction of NLP genes varies between plant hosts. Intriguingly, one of the NLP genes appears to also affect vegetative growth and conidiospore production, as the corresponding deletion strain produced significantly less conidiospores and developed extensive aerial mycelium. In conclusion, we demonstrate that the expanded V. dahliae NLP family shows functional diversification, not only revealing differential cytotoxicity between family members, but also that the cytotoxic NLPs play a role in vegetative growth and asexual reproduction in addition to their contribution to virulence.
Functional analysis and mode of action of phytotoxic Nep1-like proteins of Botrytis cinerea
Cuesta Arenas, Y. ; Kalkman, E.R.I.C. ; Schouten, A. ; Dieho, M. ; Vredenbregt, P. ; Uwumukiza, B. ; Osés Ruiz, M. ; Kan, J.A.L. van - \ 2010
Physiological and Molecular Plant Pathology 74 (2010)5-6. - ISSN 0885-5765 - p. 376 - 386.
hypersensitive response - fusarium-oxysporum - plant defense - npp1 domain - virulence - ethylene - necrosis - expression - pathogen - genes
Nep1-like proteins (NLPs) induce necrosis and ethylene production in dicotyledonous plants. Botrytis cinerea contains two genes encoding NLPs, named Bcnep1 and Bcnep2. The activity of both proteins as well as the expression and function of the genes was studied. The genes are differentially expressed during pathogenesis. Mutants in either the Bcnep1 or Bcnep2 gene were equally virulent as the wild type strain. Site-directed mutant proteins were expressed in tobacco by agroinfiltration. Mutations in a conserved motif, or in either of two N-terminal cysteine residues abolished necrosis-inducing activity. The contribution of the plant to necrosis-inducing activity of B. cinerea NLPs was investigated using Arabidopsis mutants, virus-induced gene silencing and pharmacological inhibitors. The necrosis-inducing activity of B. cinerea NLPs does not seem to require cellular processes or defense signalling pathways previously identified to be involved in pathogen-induced plant cell death.