Induction of Systemic Acquired Resistance in Papaya by Foliar Application of HrpN Recombinant Protein for Increased Resistance against Papaya Dieback Pathogen

Volume 2- Issue 3

Norliza Abu Bakar¹*, Mohd Zulfadli Sohaime¹, Nor Mustaiqazah Juri¹, Rafidah Badrun¹ and Johari Sarip²

Received: April 18, 2018;   Published: April 24, 2018

DOI: 10.32474/CIACR.2018.02.000136

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Abstract

Plants are continuously exposed to undesirable pest and pathogen threats. In response, plants have developed numerous mechanisms to protect themselves against the pathogens. Systemic acquired resistance (SAR) is an inducible disease resistance response in plant species. It is found in a large range of plant species including papaya and characterized by broad spectrum disease control and an associated coordinated expression of a set of pathogenesis related (PR) genes and proteins which are also known as SAR markers. Expression and purification of HrpN from Erwinia mallotivora, the causal agent of papaya dieback, was carried out. In this report, HrpN recombinant protein was tested and characterized for its effect and potential as elicitor that can increase papaya defence against E. mallotivora through the activation of SAR mechanism. Based on disease severity analysis, control plants which were untreated, showed faster disease infection rate and severity when compared to the recombinant protein treated plants. Increased resistance towards the papaya dieback pathogen was shown to be associated with increased expression of selected plant defined genes using quantitative Real Time analysis which were observed after the papaya was sprayed with the recombinant HrpN protein. Based on physiological and molecular analysis, the selected protein has induced SAR; increased selected SAR associated defence gene expression and increased the papaya resistance against the papaya dieback pathogen.

Keywords: Systemic acquired resistance; Recombinant protein; Erwinia mallotivora

Abbrevations: SAR: Systemic Acquired Resistance; E. mallotivora: Erwinia mallotivora; SA: Salicylic Acid; Hrp: Hairpin Proteins; PR: Pathogenesis-Related; MTI: MAMP-triggered immunity; ETI: effector-triggered immunity; SA: salicylic acid; BTH: Benzo Thiodiazole

Abstract| Core Ideas| Introduction| Materials and Methods| Plant Growth| Results and Discussion| Conclusion| Acknowledgment| References|