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- Vossen, Jack, H., et al.
(författare)
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Identification of tomato phosphatidylinositol-specific phospholipase-C (PI-PLC) family members and the role of PLC4 and PLC6 in HR and disease resistance
- 2010
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Ingår i: The Plant Journal. - 0960-7412 .- 1365-313X. ; 62:2, s. 224-239
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Tidskriftsartikel (refereegranskat)abstract
- The perception of pathogen-derived elicitors by plants has been suggested to involve phosphatidylinositol-specific phospholipase-C (PI-PLC) signalling. Here we show that PLC isoforms are required for the hypersensitive response (HR) and disease resistance. We characterised the tomato [Solanum lycopersicum (Sl)] PLC gene family. Six Sl PLC-encoding cDNAs were isolated and their expression in response to infection with the pathogenic fungus Cladosporium fulvum was studied. We found significant regulation at the transcriptional level of the various SlPLCs, and SlPLC4 and SlPLC6 showed distinct expression patterns in C. fulvum-resistant Cf-4 tomato. We produced the encoded proteins in Escherichia coli and found that both genes encode catalytically active PI-PLCs. To test the requirement of these Sl PLCs for full Cf-4-mediated recognition of the effector Avr4, we knocked down the expression of the encoding genes by virus-induced gene silencing. Silencing of SlPLC4 impaired the Avr4/Cf-4-induced HR and resulted in increased colonisation of Cf-4 plants by C. fulvum expressing Avr4. Furthermore, expression of the gene in Nicotiana benthamiana enhanced the Avr4/Cf-4-induced HR. Silencing of SlPLC6 did not affect HR, whereas it caused increased colonisation of Cf-4 plants by the fungus. Interestingly, Sl PLC6, but not Sl PLC4, was also required for resistance to Verticillium dahliae, mediated by the transmembrane Ve1 resistance protein, and to Pseudomonas syringae, mediated by the intracellular Pto/Prf resistance protein couple. We conclude that there is a differential requirement of PLC isoforms for the plant immune response and that Sl PLC4 is specifically required for Cf-4 function, while Sl PLC6 may be a more general component of resistance protein signalling.
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| 2. |
- Zhang, Bo, et al.
(författare)
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PIRIN2 stabilizes cysteine protease XCP2 and increases susceptibility to the vascular pathogen Ralstonia solanacearum in Arabidopsis
- 2014
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Ingår i: The Plant Journal. - : Wiley-Blackwell. - 0960-7412 .- 1365-313X. ; 79:6, s. 1009-1019
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Tidskriftsartikel (refereegranskat)abstract
- PIRIN (PRN) is a member of the functionally diverse cupin protein superfamily. There are four members of the Arabidopsis thaliana PRN family, but the roles of these proteins are largely unknown. Here we describe a function of the Arabidopsis PIRIN2 (PRN2) that is related to susceptibility to the bacterial plant pathogen Ralstonia solanacearum. Two prn2 mutant alleles displayed decreased disease development and bacterial growth in response to R. solanacearum infection. We elucidated the underlying molecular mechanism by analyzing PRN2 interactions with the papain-like cysteine proteases (PLCPs) XCP2, RD21A, and RD21B, all of which bound to PRN2 in yeast two-hybrid assays and in Arabidopsis protoplast co-immunoprecipitation assays. We show that XCP2 is stabilized by PRN2 through inhibition of its autolysis on the basis of PLCP activity profiling assays and enzymatic assays with recombinant protein. The stabilization of XCP2 by PRN2 was also confirmed in planta. Like prn2 mutants, an xcp2 single knockout mutant and xcp2 prn2 double knockout mutant displayed decreased susceptibility to R.solanacearum, suggesting that stabilization of XCP2 by PRN2 underlies susceptibility to R.solanacearum in Arabidopsis.
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