Journal Article

The plant defense and pathogen counterdefense mediated by Hevea brasiliensis serine protease HbSPA and Phytophthora palmivora extracellular protease inhibitor PpEPI10

Tian, Miaoying, Ekchaweng, Kitiya, Schornack, Sebastian, Evangelisti, Edouard, Churngchow, Nunta

2017

Overview

Rubber tree (Hevea brasiliensis Muell. Arg) is an important economic crop in Thailand. Leaf fall and black stripe diseases caused by the aggressive oomycete pathogen Phytophthora palmivora, cause deleterious damage on rubber tree growth leading to decrease of latex production. To gain insights into the molecular function of H. brasiliensis subtilisin-like serine proteases, the HbSPA, HbSPB, and HbSPC genes were transiently expressed in Nicotiana benthamiana via agroinfiltration. A functional protease encoded by HbSPA was successfully expressed in the apoplast of N. benthamiana leaves. Transient expression of HbSPA in N. benthamiana leaves enhanced resistance to P. palmivora, suggesting that HbSPA plays an important role in plant defense. P. palmivora Kazal-like extracellular protease inhibitor 10 (PpEPI10), an apoplastic effector, has been implicated in pathogenicity through the suppression of H. brasiliensis protease. Semi-quantitative RT-PCR revealed that the PpEPI10 gene was significantly up-regulated during colonization of rubber tree by P. palmivora. Concurrently, the HbSPA gene was highly expressed during infection. To investigate a possible interaction between HbSPA and PpEPI10, the recombinant PpEPI10 protein (rPpEPI10) was expressed in Escherichia coli and purified using affinity chromatography. In-gel zymogram and co-immunoprecipitation (co-IP) assays demonstrated that rPpEPI10 specifically inhibited and interacted with HbSPA. The targeting of HbSPA by PpEPI10 revealed a defense-counterdefense mechanism, which is mediated by plant protease and pathogen protease inhibitor, in H. brasiliensis-P. palmivora interactions.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Agar / Antiinfectives and antibacterials / Assaying / Biochemistry / Biology and Life Sciences / Calcium carbonate / Cascades / Catalysis / Cell culture / Cell walls / Chemotaxis / Chromatography / Chromatography, Affinity / Cloning / Colonization / Computational fluid dynamics / Crop production / Crops / Damage / Defense mechanisms / Degradation / Deoxyribonucleic acid / Disease control / Disease resistance / Disease Resistance - physiology / Distilled water / DNA / E coli / Effectors / Environmental protection / Environmental stress / Enzymes / Escherichia coli / Expression vectors / Gene expression / Gene silencing / Gene Transfer Techniques / Genes / Genetic aspects / Hevea - enzymology / Hevea - genetics / Hevea - parasitology / Homology / Host-Pathogen Interactions / Immune system / Immunoprecipitation / Infections / Inhibition / Inhibitors / Latex / Leaves / Nicotiana - genetics / Nicotiana - metabolism / Organisms, Genetically Modified / Pathogenicity / Pathogens / Phenols / Physical Sciences / Phytophthora - genetics / Phytophthora - metabolism / Plant diseases / Plant growth / Plant hardiness / Plant pathology / Plant protection / Plant Proteins - genetics / Plant Proteins - metabolism / Plants / Plates (structural members) / Polymerase Chain Reaction / Properties / Protease inhibitors / Protease Inhibitors - metabolism / Proteases / Proteinase inhibitors / Proteins / Recombinant Proteins - genetics / Recombinant Proteins - metabolism / Ribonucleic acid / RNA / Rubber / Rubber trees / Serine Proteases - genetics / Serine Proteases - metabolism / Tree growth / Trees / Viruses