Identification of differentially expressed genes by the cDNA-AFLP technique during dehydration of almond (Prunus amygdalus)

We analyzed several genes that were strongly expressed in response to dehyd ration of almond (Prunus amygdalus CL.) Batsch) as a means of identifying a nd determining the genetic basis of mechanisms involved in drought toleranc e. The advantages of using almond as a model system for studying dehydratio n tolerance in woody species include its small diploid genome and its adapt ation to drought. We used the differential expression technique cDNA-AFLP ( amplified restriction fragment polymorphism derived technique for RNA finge rprinting) to identify transcripts that accumulated in mature embryos and i n in-vitro-cultured plantlets subjected to desiccation or abscisic acid (AB A) treatment. The reverse northern approach was used to differentiate betwe en true differential bands and false positives. Some of the predicted polyp eptides exhibited similarity to published protein sequences, including a tr ansporter of nitrogenous compounds, a 1-acyl-sn-glycerol-3-phosphate acyl t ransferase, a low molecular weight heat shock protein, a cysteine proteinas e and a constitutively expressed proline-rich protein. We also compared the levels of expression of the identified genes in leaves of young trees of e ight almond cultivars differing in drought tolerance.