Proceedings of the XLVI Italian Society of Agricultural Genetics - SIGA Annual Congress

Giardini Naxos, Italy - 18/21 September, 2002

ISBN 88-900622-3-1

Poster Abstract - 1.25

Differential expression of three members of the manganese superoxide dismutase gene family during the seasonal development of buds of peach trees (Prunus laevis DC)

Bagnoli F., Bardazzi I.

Dipartimento di Biotecnologie Agrarie, Laboratorio di Genetica, Università degli Studi di Firenze, Piazzale delle Cascine 24, 50144 Firenze, Italia

bud, development, gene expression, manganese superoxide dismutase, peach

All organisms exposed to an aerobic environment are subjected to the toxic effects of active oxygen species (AOS) such as superoxide, H₂O₂, and the hydroxyl radical. In plants the cellular concentration of oxygen is the highest among organisms, due to their oxygen-evolving capabilities. Consequently, the antioxidant enzymes in plants have a crucial role in oxidative stress protection. In fact superoxide dismutases (SOD), together with catalases and peroxidases, represent the major defence against cell oxidation. Moreover, SODs have been reported to be very sensitive to metabolic changes during cell life and respond to developmental stimuli.

In peach MnSOD gene belong to a small multigene family such as in wheat and in maize. In fact, three different Mnsod cDNAs, one full-length (Mnsod1) and two partial sequences (Mnsod2 and Mnsod3), have been isolated from peach leaves in our laboratory. The three Mnsod showed high homology except for the 3’ UTR regions and RT-PCR experiments evidenced the presence of the three cDNAs in leaves derived from plants of different ages and in adult plants during the seasonal cycle.

Activity gel data, previously obtained, evidenced the presence of at least three MnSOD isoforms with a different enzymatic activity. Therefore in the present study we focused our attention on the expression pattern of each individual peach MnSOD gene during the seasonal development of peach buds. In particular, we consider floral and vegetative buds at the following developmental stages: induction, differentiation, dormancy and pre-blooming.

Preliminary results, obtained by relative quantitative RT-PCR analysis, indicate that individual members of MnSOD gene family are differentially expressed in floral and vegetative buds during development.