ABSTRACT
Aeluropus lagopoides is a salt and drought tolerant grass from Poaceae family, distributed widely in arid regions. There is almost no information about the genetics or genome of this close relative of wheat that stands harsh conditions of deserts. The main aim of this research was to isolation and characterization of salt and drought inducible genes from A. lagopoides by Differential Display Amplified fragment length polymorphism [DD-AFLP] method. In this research A. lagopoides was grown under salt or drought conditions and after modifying the DD-AFLP method several fragments were isolated and after nomination their induction was studied by reverse northern blotting. DD-AFLP led to the improvement of a non-radioactive method for which many parameters were optimized. Having screened approximately 1600 transcript-derived fragments, 1.4 percent of them showed varied expression levels in response to high salt or drought treatments. The relative abundance of twenty one selected differentially expressed fragments was inspected by reverse northern blotting that affirmed the potential of this applied method. Sequence comparisons revealed that some of the isolated genes are involved in osmotic adjustment, regulation of transcription, cation transportation and stress responses. These data clearly show that the modified DD-AFLP method was a successful and reliable approach for the isolation of differentially expressed genes
ABSTRACT
Phenylalanine amonia-lyase [PAL] is one of the most important enzymes that plays a key role in regulation of phenylpropanoid production in plants. It catalyzes the first step of the phenylpropanoid pathway in which L-phenylalanine is deaminated to trans-cinnamic acid. This step is significant for metabolic engineering and hyper-expression of the major phenylpropanoid, methyl chavicol. We followed gene expression and activity of PAL in Ocimum basilicum L. at different stages of growth including seedling, beginning and middle of growth phase, budding stage and flowering, and their correlation with final concentration of phenylpropanoid compounds. The level of gene expression was monitored by semi quantitative RT-PCR and phenylpropanoid compounds were identified by gas chromatography/mass spectrometry [GC/MS]. PAL activity was assayed using spectrophotometer. The results indicated that the level of gene expression and activity of PAL enzyme are altered during the plant development, where the highest expression and activity [0.851 [micromol cinnamic acid/mg/min] was achieved at budding stage. In this experiment, changes of methylchavicol content were correlated to the transcription and activity of PAL enzyme