Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Leaf Cuticle Can Contribute to Non-Host Resistance to Poplar Leaf Rust
The plant leaf cuticle is a chemically complex but largely waxy outer shell that limits water loss and also prevents some pathogens from gaining access to internal mesophyll. Rust fungi are obligate parasites, and most bypass the cuticle by thigmotropically locating stomata, growing through the stomatal openings, and then parasitizing mesophyll cells with haustoria. It is thought that even non-hosts of a given rust fungus do not resist until their mesophyll cells are contacted in this way. In other words, it is thought that the cuticle plays no role in non-host resistance. Here, we tested the hypothesis that poplar leaf cuticles might contribute to non-host resistance to rust fungi by chemically impeding the germination and growth of urediniosporelings of Melampsora larici-populina. Following an initial survey in China of the resistance of 36 genotypes of various species and interspecific hybrids of Populus to M. larici-populina, we selected three genotypes for the initial test of hypothesis: (1) A Populus purdomii genotype that is fully susceptible; (2) a Populus deltoides cv. ‘I-69’ that is incompletely resistant (i.e., a resistant host); and (3) a Populus tomentosa genotype that is a non-host to M. larici-populina. Urediniospores were assayed for germination in extracts of the cuticles of the three genotypes. Germination was most reduced by the P. tomentosa non-host cuticular extracts that also reduced the growth of germ tubes to 36 times less than that in controls or in the extract of the susceptible P. purdomii. Four cuticular components were identified as putative defense compounds given greater concentrations in P. tomentosa than in P. purdomii: Aucubin, hexakis(trimethylsilyl) ether, catechol, 7,9-Di-tert-buty l-1-oxaspiro (4,5) deca-6, 9-diene-2,8-dione and trifluoroacetamide. These four compounds were then tested, and they reduced urediniospore germination and uredinial density in inoculations of normally susceptible P. purdomii with Melampsora larici-populina. Thus, the cuticle of P. tomentosa can contribute to pre-haustorial, non-host resistance to M. larici-populina.
Leaf Cuticle Can Contribute to Non-Host Resistance to Poplar Leaf Rust
The plant leaf cuticle is a chemically complex but largely waxy outer shell that limits water loss and also prevents some pathogens from gaining access to internal mesophyll. Rust fungi are obligate parasites, and most bypass the cuticle by thigmotropically locating stomata, growing through the stomatal openings, and then parasitizing mesophyll cells with haustoria. It is thought that even non-hosts of a given rust fungus do not resist until their mesophyll cells are contacted in this way. In other words, it is thought that the cuticle plays no role in non-host resistance. Here, we tested the hypothesis that poplar leaf cuticles might contribute to non-host resistance to rust fungi by chemically impeding the germination and growth of urediniosporelings of Melampsora larici-populina. Following an initial survey in China of the resistance of 36 genotypes of various species and interspecific hybrids of Populus to M. larici-populina, we selected three genotypes for the initial test of hypothesis: (1) A Populus purdomii genotype that is fully susceptible; (2) a Populus deltoides cv. ‘I-69’ that is incompletely resistant (i.e., a resistant host); and (3) a Populus tomentosa genotype that is a non-host to M. larici-populina. Urediniospores were assayed for germination in extracts of the cuticles of the three genotypes. Germination was most reduced by the P. tomentosa non-host cuticular extracts that also reduced the growth of germ tubes to 36 times less than that in controls or in the extract of the susceptible P. purdomii. Four cuticular components were identified as putative defense compounds given greater concentrations in P. tomentosa than in P. purdomii: Aucubin, hexakis(trimethylsilyl) ether, catechol, 7,9-Di-tert-buty l-1-oxaspiro (4,5) deca-6, 9-diene-2,8-dione and trifluoroacetamide. These four compounds were then tested, and they reduced urediniospore germination and uredinial density in inoculations of normally susceptible P. purdomii with Melampsora larici-populina. Thus, the cuticle of P. tomentosa can contribute to pre-haustorial, non-host resistance to M. larici-populina.
Leaf Cuticle Can Contribute to Non-Host Resistance to Poplar Leaf Rust
Zhongdong Yu (Autor:in) / Kuocheng Shen (Autor:in) / George Newcombe (Autor:in) / Junfeng Fan (Autor:in) / Qianwen Chen (Autor:in)
2019
Aufsatz (Zeitschrift)
Elektronische Ressource
Unbekannt
Metadata by DOAJ is licensed under CC BY-SA 1.0
Effects of Melampsora leaf rust disease and chronic ozone exposure on poplar
| Online Contents | 1999
The First Record of a North American Poplar Leaf Rust Fungus, Melampsora medusae, in China
| DOAJ | 2019
Molecular markers for leaf rust resistance genes in wheat
| British Library Online Contents | 2001
Resistance of spring wheat cultivars and lines to leaf rust
| British Library Online Contents | 2003