Expression of tobacco class II catalase gene activates the endogenous homologous gene and is associated with disease resistance in transgenic potato plants

Citation
Dq. Yu et al., Expression of tobacco class II catalase gene activates the endogenous homologous gene and is associated with disease resistance in transgenic potato plants, PLANT MOL B, 39(3), 1999, pp. 477-488
Citations number
55
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Plant Sciences","Animal & Plant Sciences
Journal title
PLANT MOLECULAR BIOLOGY
ISSN journal
0167-4412 → ACNP
Volume
39
Issue
3
Year of publication
1999
Pages
477 - 488
Database
ISI
SICI code
0167-4412(199902)39:3<477:EOTCIC>2.0.ZU;2-J
Abstract
We have previously shown that healthy potato plants respond poorly to salic ylic acid (SA) for activating disease resistance against the late blight fu ngal pathogen Phytophthora infestans. However, SA is essential for the esta blishment of potato systemic acquired resistance (SAR) against P. infestans after treatment with the fungal elicitor arachidonic acid (AA). To underst and the molecular mechanisms through which AA induces SA-dependent SAR in p otato, we have recently studied the expression of potato class IT catalase (Cat2St) in comparison with its tobacco homologue, Cat2Nt, which has previo usly been shown to bind SA. In the present study, we show that tobacco Cat2 Nt is expressed at high levels and accounts for almost half of total SA-bin ding activity detected in tobacco leaves. In contrast, potato Cat2St is not expressed in healthy leaves, which is associated with the low SA responsiv eness of potato plants for activation of disease resistance mechanisms. Upo n treatment with AA, expression of potato Cat2St is induced not only in AA- treated leaves, but also in the upper untreated parts of the plants, concom itant with the establishment of SA-dependent SAR to P. infestans. Moreover, expression of the tobacco Cat2Nt gene in transgenic potato plants leads to constitutive expression of the endogenous potato Cat2St gene and is associ ated with enhanced resistance to P. infestans. These results collectively i ndicate that plant SA-binding class II catalases may play an important role in the development of disease resistance, possibly by serving as biologica l targets of SA.