Rust haustoria: nutrient uptake and beyond

Abstract

SummaryHaustoria are morphological features of an extremely successful class of plant parasites, the obligate biotrophs. The broad phylogenetic spectrum of organisms producing haustoria suggests that these structures have arisen many times in the course of evolution and represent specific adaptations of these organisms to the close interaction with their respective host plants. This close interaction and the fact that these structures cannot be produced in vitro have hampered an analysis of the roles of haustoria in biotrophy for many decades. Only recently has it become possible to analyse haustorial function at a molecular level. A picture is beginning to emerge indicating that haustoria do not only serve in nutrient uptake -a task postulated for these elements ever since their discovery. Moreover, they seem to perform enormous biosynthetic duties. They also seem to be engaged in the suppression of host defense responses and in redirecting or reprogramming the host's metabolic flow. This review intends to summarize current knowledge about the structure and function especially of rust haustoria.

In Planta Proteomics and Proteogenomics of the Biotrophic Barley Fungal Pathogen Blumeria graminis f. sp. hordei>

“…6A), the global functional distribution of proteins in conidia and the sporulating hyphae was very similar, whereas the haustorial proteome showed intriguing differences. The over-representation of carbohydrate metabolism in general and monosaccharide metabolism in particular was not surprising given our understanding that haustoria are the primary feeding structures (25) and that monosaccharides are thought to be the main form of fixed carbon taken up by the fungus (26). This also correlates well with our previous findings based on analysis of transcriptome dynamics where we have shown that genes encoding glycolytic enzymes are coordinately up-regulated in haustoria (8).…”

Coffee resistance to the main diseases: leaf rust and coffee berry disease

“…The following properties appear to be hallmarks of these fungi: (i) highly developed infection structures; (ii) limited secretory activity, especially of lytic enzymes; (iii) carbohydrate-rich and protein-containing interfacial layers that separate fungal and plant plasma membranes; (iv) haustoria, which are specialized hyphae for nutrient absorption and metabolism; (v) both long-term suppression of host defences and induction of specific host genes for the establishment of biotrophy (Mendgen and Hahn, 2002;Shulze-Lefert and Panstruga, 2003;Voegele and Mendgen, 2003).…”

The Melampsora lini AvrL567 Avirulence Genes Are Expressed in Haustoria and Their Products Are Recognized inside Plant Cells

“…One of the primary functions of haustoria seems to be to facilitate nutrient uptake from the host (Hahn and Mendgen, 2001). Haustoria formation also induces structural changes in the host cell, including cytoskeletal rearrangements, nuclear migration, and chromatin condensation (Kobayashi et al, 1994;Heath, 1997), and there is some evidence that compatible rusts can suppress host defense responses and influence host cell metabolism (Mellersh and Heath, 2001;Ayliffe et al, 2002;Voegele and Mendgen, 2003). However, the signals leading to these changes are not known.…”