Abstract Detail



Symbioses: Plant, Animal, and Microbe Interactions

Twayana , Moon [1], Shah, Jyoti [1].

A putative resistance gene HOMOLOG OF RPW8.1 4 (HR4) is required for the plant defense against the green peach aphid.

Resistance genes have principal functions in plant defense against pathogens and pests. The RESISTANCE AGAINST POWDERY MILDEW8 (RPW8) locus of Arabidopsis thaliana accession Moscow-0 (Ms-0) has two non-canonical resistance genes RPW8.1 and RPW8.2 that confer resistance against powdery mildew. In the accession Columbia (Col-0), which is susceptible to the powdery mildew, this locus contains the HOMOLOG OF RPW8.1 4 (HR4) gene instead of RPW8.1 and RPW8.2. We find that HR4 contributes to basal resistance against the green peach aphid (GPA; Myzus persicae Sülzer), which is an important pest of a wide variety of plants from over 130 families. In no-choice assay, which monitors the combined effects of antixenosis and antibiosis, the GPA colonization was greater on the hr4 mutant than in wild type (WT). Aphid fecundity was significantly higher on the hr4 mutant than on the WT. Artificial diet assays demonstrated that phloem sap-enriched petiole exudates collected from the hr4 mutant accumulate lower levels of an antibiosis activity against the GPA, which results in increased fecundity of the GPA on the hr4 mutant compared to the WT. Although when given a choice the GPA does not show preference in which plants it chooses to settle on, dispersal assays indicate that in comparison to the WT plants, emigration of GPA from hr4 mutant was reduced, thus indicating that the insect prefers to stay on hr4 plant compared to the WT plant. HR4 is required for turning on the premature senescence and cell-death in response to elicitors derived from GPA. We hypothesize that HR4 is required for response to the aphid-derived elicitors of plant defense. Future efforts are directed towards understanding the molecular and physiological mechanism underlying HR4’s function in defense against the GPA


1 - University of North Texas, Biological Sciences, Denton, Texas, 76203, USA

Keywords:
HR4
RPW8
Arabidopsis thaliana
Green Peach Aphid
Antibiosis.

Presentation Type: Oral Paper
Number:
Abstract ID:699
Candidate for Awards:None


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