Rol del glutation en la simbiosis rhizobio-mani

BIANUCCI ELIANA, TORDABLE MARíA DEL CARMEN, FABRA ADRIANA, CASTRO STELLA

Rosario, Santa Fe

Congreso; XLII Reunion Anual Sociedad Argentina de Investigacion en Bioquimica y Biologia Molecular; 2006

SAIB

It is known that glutathione (GSH) is essential in the nodulation process by infection threads in the rhizobia-legume symbiosis. In the case of rhizobia-peanut symbiosis, there are no infection threads, instead, infection through the epidermis involves intercellular penetration. We previously studied the importance of GSH in Bradyrhizobium sp. SEMIA6144 using a GSH-deficient mutant obtained by disruption of the gshA gene, encoding ã-glutamylcysteine synthetase (ãECS), which was able to induce nodules in peanut roots. To investigate the involvement of the peanut GSH content in the symbiosis, a strategy aimed at modifying the GSH pool was developed using L-buthionine-sulfoximine (BSO), a specific inhibitor of ãECS in plants. Peanut seedlings were grown in the Farhaeus medium either in the presence or absence of BSO (0.1 to 1 mM). The concentration of 0.1 mM BSO did not modify the plant growth and the typical anatomic structure of the peanut roots. However, the GSH content was reduced by 51% after treatment with BSO. This concentration was chosen to further analyze the implication of GSH in the nodulation process. Preliminary results showed that BSO-treated plants and inoculated with wild-type strain formed fewer nodules than control plants suggesting that the peanut GSH content could have a role in the establishment of the symbiosis.