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

Verona, Italy - 24/27 September, 2003

ISBN 88-900622-4-X

Poster Abstract - 1.53

"STAY GREEN" MUTANTS OF DURUM WHEAT: ANALYSIS AT MOLECULAR LEVEL

P. RAMPINO*, G. SPANO**^,***, P.R. SHEWRY****, J.A. NAPIER****, C. PERROTTA*, N. DI FONZO***

*) DiSTeBA, Università di Lecce

**) Dip. Scienze Alimentari, Università di Foggia

***) Ist. Sper. Cerealicoltura-Foggia

****) Long Ashton Res. Station, Dept. of Agricultural Sciences, University of Bristol

stay green, durum wheat, molecular analysis, differential display

Examples of the ‘stay green’ phenotype have been identified in a number of crop species (Thomas and Howart, 2000) and, although this phenotype is superficially similar in all species the genetics and physiological routee to the trait may differ. To elucidate the molecular mechanisms responsible for the ‘stay green’ phenotype is relevant not only to understand the senescence phenomenon itself but also for practical purposes, such as yield improvement. Four mutants with delayed leaf senescence were obtained by ethylmethanesulfonate (EMS) mutagenesis of durum wheat (cv Trinakria). All the photosynthetic parameters seem to be affected in these mutants (Spano et al, 2003), that have the characteristics of functional ‘stay green’ according to Thomas and Howarth (2000). This type of ‘stay green’ mutants may arise by alteration of genes involved in the timing of the initiation of senescence, or in the regulation of its rate of progress (Smart, 1994). In order to identify genes whose expression is up or down-regulated in our mutants, a comparative analysis between mutant and control plants was performed by differential display of mRNAs. Total RNA was extracted from the flag leaves of plants grown in a controlled glasshouse, and different primer combinations were used. About 20 fragments were confirmed as differentially expressed in leaves of mutant plants. These fragments were cloned and subsequently sequenced. BLAST analysis of the sequences obtained was performed.

References

Spano et al, 2003, J. Exp. Bot. 54: 1415-1420

Thomas and Howart, 2000, J. Exp. Bot. 51: 329-337

Thomas and Smart, 1993, Ann. Appl. Biol. 123:193-203