During the different phases of mycorrhizal fungi life cycle, several morphological, genetic and metabolic modifications are induced for both symbiotic partners. These changes are influenced by multiple environmental factors: light, gravity, oxygen, temperature, soil typology, nutrient availability, root exudates (that may content sugars) and the presence of particular bacterial populations in the mycorrhizosphere. Herein, in order to verify if nutritional supply leads to cell signaling events and morpho-functional changes in Tuber borchii pure culture, the expression level of genes involved in the apical growth, was investigated using the array technique, on mycelia grown on culture media containing different carbon sources. Membranes were prepared using ESTs involved in polarized growth, such as: S97, codifying the protein sec1, responsible for binding Syntaxin and involved in vesicle membrane fusion; S102, involved in apical growth, that codify a 1,3-beta-glucanosil transferase responsible for cell wall assembly of fungi; S32, directly involved in cell nuclear migration towards hyphae apical tips by cytoskeleton. The results obtained by morphological analyses highlighted an increased growth of T. borchii mycelium in the presence of glucose, while the hyphae are thinner and less branched in the presence of sucrose and maltose. These data were confirmed by gene expression analyses: the genes involved in apical grown and general metabolism are more expressed. Since glucose is also present in root plant exudates, it can act as a signal for the fungus to indicate the presence of the plant, and to induce the complex symbiotic process. These mechanisms can lead to morphological modifications, among which an increase branching, necessary for the fungus to get closer to the plant roots and establish a contact. This study represents a starting point to identify and characterise genes and proteins involved in the complex morphological, genetic and metabolic modifications that happens during Tuber life cycle.
Morphological and molecular modifications induced by different carbohydrate sources in Tuber borchii Vittad. mycelium / Amicucci A.; ZAMBONELLI A.; Iotti M.; MENOTTA M.; SALTARELLI R.; ZEPPA S.; STOCCHI V.. - ELETTRONICO. - (2007), p. 193. (Intervento presentato al convegno XIII international Congress on molecular plant-microbe interactions tenutosi a Sorrento, Italy nel 21-27 luglio 2007).
Morphological and molecular modifications induced by different carbohydrate sources in Tuber borchii Vittad. mycelium
ZAMBONELLI, ALESSANDRA;IOTTI, MIRCO;
2007
Abstract
During the different phases of mycorrhizal fungi life cycle, several morphological, genetic and metabolic modifications are induced for both symbiotic partners. These changes are influenced by multiple environmental factors: light, gravity, oxygen, temperature, soil typology, nutrient availability, root exudates (that may content sugars) and the presence of particular bacterial populations in the mycorrhizosphere. Herein, in order to verify if nutritional supply leads to cell signaling events and morpho-functional changes in Tuber borchii pure culture, the expression level of genes involved in the apical growth, was investigated using the array technique, on mycelia grown on culture media containing different carbon sources. Membranes were prepared using ESTs involved in polarized growth, such as: S97, codifying the protein sec1, responsible for binding Syntaxin and involved in vesicle membrane fusion; S102, involved in apical growth, that codify a 1,3-beta-glucanosil transferase responsible for cell wall assembly of fungi; S32, directly involved in cell nuclear migration towards hyphae apical tips by cytoskeleton. The results obtained by morphological analyses highlighted an increased growth of T. borchii mycelium in the presence of glucose, while the hyphae are thinner and less branched in the presence of sucrose and maltose. These data were confirmed by gene expression analyses: the genes involved in apical grown and general metabolism are more expressed. Since glucose is also present in root plant exudates, it can act as a signal for the fungus to indicate the presence of the plant, and to induce the complex symbiotic process. These mechanisms can lead to morphological modifications, among which an increase branching, necessary for the fungus to get closer to the plant roots and establish a contact. This study represents a starting point to identify and characterise genes and proteins involved in the complex morphological, genetic and metabolic modifications that happens during Tuber life cycle.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
