In:
BMC Plant Biology, Springer Science and Business Media LLC, Vol. 11, No. 1 ( 2011-12)
Kurzfassung:
Treatment of plants with HrpN Ea , a protein of harpin group produced by Gram-negative plant pathogenic bacteria, induces plant resistance to insect herbivores, including the green peach aphid Myzus persicae , a generalist phloem-feeding insect. Under attacks by phloem-feeding insects, plants defend themselves using the phloem-based defense mechanism, which is supposed to involve the phloem protein 2 (PP2), one of the most abundant proteins in the phloem sap. The purpose of this study was to obtain genetic evidence for the function of the Arabidopsis thaliana (Arabidopsis) PP2-encoding gene AtPP2-A1 in resistance to M. persicae when the plant was treated with HrpN Ea and after the plant was transformed with AtPP2-A1 . Results The electrical penetration graph technique was used to visualize the phloem-feeding activities of apterous agamic M. persicae females on leaves of Arabidopsis plants treated with HrpN Ea and an inactive protein control, respectively. A repression of phloem feeding was induced by HrpN Ea in wild-type (WT) Arabidopsis but not in atpp2-a1 /E/142, the plant mutant that had a defect in the AtPP2-A1 gene, the most HrpN Ea -responsive of 30 AtPP2 genes. In WT rather than atpp2-a1 /E/142, the deterrent effect of HrpN Ea treatment on the phloem-feeding activity accompanied an enhancement of AtPP2-A1 expression. In PP2OETAt ( AtPP2-A1 -overexpression transgenic Arabidopsis thaliana ) plants, abundant amounts of the AtPP2-A1 gene transcript were detected in different organs, including leaves, stems, calyces, and petals. All these organs had a deterrent effect on the phloem-feeding activity compared with the same organs of the transgenic control plant. When a large-scale aphid population was monitored for 24 hours, there was a significant decrease in the number of aphids that colonized leaves of HrpN Ea -treated WT and PP2OETAt plants, respectively, compared with control plants. Conclusions The repression in phloem-feeding activities of M. persicae as a result of AtPP2-A1 overexpression, and as a deterrent effect of HrpN Ea treatment in WT Arabidopsis rather than the atpp2-a1 /E/142 mutant suggest that AtPP2-A1 plays a role in plant resistance to the insect, particularly at the phloem-feeding stage. The accompanied change of aphid population in leaf colonies suggests that the function of AtPP2-A1 is related to colonization of the plant.
Materialart:
Online-Ressource
ISSN:
1471-2229
DOI:
10.1186/1471-2229-11-11
Sprache:
Englisch
Verlag:
Springer Science and Business Media LLC
Publikationsdatum:
2011
ZDB Id:
2059868-3
SSG:
12
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