The tb11.9 gene from the white truffle Tuber borchi encodes for a structural cell wall protein specifically expressed in fruitbody

AGOSTINI, DEBORAH¹, ROBERTA DE BELLIS¹, LUCIA POTENZA¹, EMANUELA POLIDORI¹, GIOVANNI PICCOLI¹, LUCIANA VALLORANI¹, DAVIDE SISTI² & VILBERTO STOCCHI¹.

¹Istituto di Chimica Biologica "Giorgio Fornaini", Università di Urbino, Via Saffi, 2 - 61029 Urbino (PS) - ITALY. ² Istituto Orto Botanico, Via Bramante, 28 - 61029 Urbino (PS) - ITALY.

At present little is known about the mechanisms leading to fruitbody formation and whether or not they are the result of plant-fungus interaction. In order to investigate the cell cycle of Tuber we purified a protein present only in the fruitbody of Tuber borchii Vittad. and we cloned the encoding gene. The protein TB11.9 is detectable by SDS-PAGE analyses only in this white truffle species and presents a molecular mass of 11,994 Da. TB11.9 was purified by one-step RP-HPLC and its complete amino acid sequence was determined after digestion. The tb11.9 gene was cloned using several techniques involving PCR; a putative signal peptide was found at the N-terminal. Northern blot analysis showed that tb11.9 is highly expressed in unripe and ripe fruitbodies and is not detectable in mycelium or ectomycorrhizal roots. Further studies will be carried out in order to characterise the promoter and to establish the function of TB11.9 as it didn't show any significant similarity with known function proteins.

Key words: Tuber borchii, fruitbody, HPLC purification, PCR cloning.