Showing 2 results for A. Yamchi
A. Yamchi, F. Rastgar Jazii, C. Ghobadi, A. Mousavi, A. A. Karkhanehee,
Volume 8, Issue 4 (winter 2005)
Abstract
Proline as a key osmoregulating solute in plants plays an overriding role in osmotic pressure adjustment of the cell under water stress conditions. In plant, a bifunctional enzyme delta-1-pyrroline-5-carboxylate synthetase (p5cs) promotes and directs proline synthesis during drought stress conditions. The activity of this enzyme is strongly induced to increase proline concentration within the cell to prevent the impact of water deficit. In this study, the sequence coded for p5cs enzyme under the control of the cauliflower mosaic virus 35S promoter was cloned into a plasmid containing gus and nptII genes. The construct pBI121-p5cs was then transferred into Agrobacterium tumefaciens C58 (pGV3101) and used for producing transgenic tobacco(Nicotiana tabacum cv. Xanthi) plants. The amplification of a 765 bp band within p5cs gene from transferred plants and forming deep blue color in leaf tissues of the explants indicated the successful introduction of p5cs construct into nuclear genome of tobacco plants through Agrobacterium-mediated transformation. The two-month old plants growing under normal condition besides the five-day seedlings under drought stress were subjected to determination of proline concentration. Comparison of P5cs product levels between control and water tolerated plants indicated an increase of proline of about 96.91 to 1330.891 mg/g and of 204.454 to 2039.77 mg/g in plants under normal irrigation and under drought stress, conditions respectively. The significant difference between the levels of proline product in control and transgenic plants under different growing conditions demonstrated the expression of targeted gene (p5cs) in engineered tobacco plants that may pave the way to overcome the water stress problem in agronomically useful crops.
M. Bahar, S. Ghobadi, V. Erfani Moghaddam, A. Yamchi, M. Talebi Bedaf, M. M. Kaboli, A. A. Mokhtarzadeh,
Volume 10, Issue 2 (summer 2006)
Abstract
To determine genetic diversity among some Iranian local varieties of alfalfa, six geographically diverse populations including: Bami, Rahnani, Nikshahri, Yazdi, Hamadani (from Isfahan), Hamadani (from Shiraz) along with Ranger, an American commercial variety, were evaluated using a set of 24 EST-SSR primers developed from cDNA library of Medicago truncatula and three microsatellite loci, identified from genomic library of M. sativa. Of the pairs of primers tested, four loci from EST-SSRs (AW9, BEE, TC6 and TC7) and genomic microsatellite (Afctt32), were found appropriate for assessing genetic diversity between these alfalfa genotypes. In total, 46 alleles were detected from the five loci in the samples of alfalfa examined. The number of alleles per locus in populations ranged from six to eleven and genetic diversity indices of loci were variable from 0.62 to 0.87 for the populations. Genetic relationship analysis of EST-SSR data revealed separation of Iranian populations from Ranger. It is likely that the parental origin of primary population from which Ranger has been derived is different from that of Iranian populations. Iranian local populations of alfalfa in this study were grouped in two main clusters. Alfalfa populations Hamadani and Rahnani, which are adapted to cold claimates, were grouped in one cluster and populations Bami, Yazdi and Nikshahri, belonging to the trpoical areas, were placed in the next cluster. The positioning of EST-SSR loci in coding regions of genome, possibly increases the usefulness of these markers to clarify inter specific genetic relationships among alfalfa populations.
