Diversity of nitrogen-fixing bacteria and the nitrogen-fixation activity was investigated in Tuber magnatum, the most well-known prized species of Italian white truffle. Degenerate PCR primers were applied to amplify the nitrogenase gene nifH from T. magnatum ascomata at different stages of maturation. Putative amino acid sequences revealed mainly the presence of Alphaproteobacteria belonging to Bradyrhizobium spp. and expression of nifH genes from Bradyrhizobia was detected. The nitrogenase activity evaluated by acetylene reduction assay was 0.5e7.5 mmol C2H4 h_1 g_1, comparable with early nodules of legumes associated with specific nitrogen-fixing bacteria. This is the first demonstration of nitrogenase expression gene and activity within truffle.
New evidence for nitrogen fixation within the Italian white truffle Tuber magnatum
BARBIERI, ELENA;CECCAROLI, PAOLA;SALTARELLI, ROBERTA;POTENZA, LUCIA ANNA MARIA;STOCCHI, VILBERTO
2010
Abstract
Diversity of nitrogen-fixing bacteria and the nitrogen-fixation activity was investigated in Tuber magnatum, the most well-known prized species of Italian white truffle. Degenerate PCR primers were applied to amplify the nitrogenase gene nifH from T. magnatum ascomata at different stages of maturation. Putative amino acid sequences revealed mainly the presence of Alphaproteobacteria belonging to Bradyrhizobium spp. and expression of nifH genes from Bradyrhizobia was detected. The nitrogenase activity evaluated by acetylene reduction assay was 0.5e7.5 mmol C2H4 h_1 g_1, comparable with early nodules of legumes associated with specific nitrogen-fixing bacteria. This is the first demonstration of nitrogenase expression gene and activity within truffle.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
