Journal of Cell and Molecular Research

61-67

Authors: Maria Beihaghi, Ahmad Reza Bahrami, Abdolreza Bagheri, Richard Leegood

Phosphoenolpyruvate Carboxykinase, encoded by the pepck gene, plays an important role in gluconeogenesis. It also seems to be important in metabolism of nitrogenous compounds in developing seeds of legumes, including amides and ureides which are then transformed into amino acids, necessary for the synthesis of storage proteins. In this research, pepck gene expression in mRNA level, in different genotypes of chickpea (Cicer arietinum L.), was determined. Two low protein genotypes (MCC291 and MCC373) and two high protein genotypes (MCC458 and MCC053) out of 20 chickpea genotypes were selected. Total RNA were extracted through different stages of seed development, and the expression of the pepck gene was estimated by semi-quantitative RT-PCR. The results of the RT-PCR showed that two isoforms of this gene are expressed in high protein genotypes, whereas in the low protein genotypes, the expression of these isoforms was not obvious. Also this method showed a differential expression of pepck gene in different stages of flowering and seed development. pepck gene is expressed in higher levels during the sheet formation and developing seeds compared to the flowering and seed formation stages. Probably, the differential expression of pepck gene is related to its possible role in metabolism of seed components, particularly in determination of the protein content of chickpea seeds.

72-76

Authors: Samira Padidar, Mehran Miroliaei, Ali Mostafaie and Sirous Ghobadi

Plant nonspecific lipid transfer proteins (nsLTPs) are divided into nsLTP1 and nsLTP2. The existence of an internal hydrophobic cavity, is a typical characteristic of nsLTPs that serves as the binding site for lipid substrates. In this communication a simple, rapid and low-cost alternative method was developed for purification of nsLTP2 from rice paddy. After extracting, final supernatant was loaded on CM-Sepharose column, which had previously equilibrated with 0.05 M Tris-HCl buffer, pH 8. Bounded proteins were separated using a linear gradient of 0-0.5 M NaCl. Solution of separated proteins was dialyzed and applied on a Phenyl-Sepharose column which previously equilibrated with Tris-HCl 0.05 M, ammonium sulfate 1.5 M, EDTA 0.005 M and NaHSO3 0.3%, pH 8.4. Tris-Tricin SDS-PAGE of separated proteins, obtained from ion- exchange column, showed multiple bands in the range of 2-20 kDa. Further purification using hydrophobic column resulted in single band of nsLTP2 at about 7 kDa, reflecting a purified sample in the gel.

84-90

Authors: Sasan Mohsenzadeh, Sahar Sadeghi, Hassan Mohabatkar and Ali Niazi

Osmotic stress is one of the major factors that significantly reduce yields in dry areas. Plants respond to this abiotic stress at physiological and molecular levels. Many genes are induced under stress conditions by transcription factors. Dehydration responsive element binding (DREB) protein is a subfamily of AP2/ERF transcription factors which control expression of many osmotic stress-inducible genes. In this study, 21 days old seedlings of Sardari cultivar, dry farming bread wheat transferred into hydroponics culture using Hoagland solution. Osmotic stress treatments performed with adding 100, 200 and 400 g/l poly-ethylene glycol 6000 to hydroponics culture to obtain –0.15, –0.49, and –1.76 MPa water potential, respectively. After the seedlings were withered and colorless, relative water content, dry weight, and photosynthesis measured. In addition, RT- PCR, and cDNA sequencing carried out. Molecular analysis of DREB translated protein sequence performed by DNAMAN, BLASTN, Pfam and PROSITE software. Results showed that osmotic stress decreased relative water content, root and shoot dry weight and net photosynthesis rate in comparison to control, significantly (P < 0.05). Sequence alignment indicated 98% homology with other Triticum aestivum DREB protein mRNA. There was an AP2 domain in the translated protein with three -sheets and one -helix and contains the Val14 and Glu19 amino acids. An EST Sequence deposited in NCBI GenBank database with the accession number of ES466900.

97-105

Authors: Saeed Shafiei Sabet, Mohammad Reza Imanpoor and Bagher Aminian fatideh

Relation between sexual maturity and levels of two main steroid hormones in gonads, 17- estradiol (E2) and testosterone (T) were studied by using histological and radioimmunoassay in female kutum Rutilus frisii kutum during spawning season of the southern Caspian Sea. The study was carried out from February to May 2008 using 105 migrated fish specimens catched from the River sefid-rood by various tools of catching including (Gillnet, Cast net, Seine net and Sheyl or Kulham). The results revealed that changes in plasma levels of gonadal steroids, (E2) and (T) were closely correlated with ovarian development and increased in Gonadosomatic index (GSI) (P<0.05). GSI was increased in March and reached the highest value (29.47±4.2) in April. It was then decreased sharply in early May. The highest peak of plasma level of (T) and (E2) was during spawning season and it was associated with the GSI. The results showed that levels of (E2) and (T) in female kutum at the stage IV of sexual maturity was significantly higher than immature gonads (ovary in stages II and III) (P<0.01). Plasma (E2) and (T) levels increased in February, the highest levels were observed in March and the early of April (105.6±75.3 and 29.2±96.6 ng/ml), respectively. It was decreased in the late of April and in the early of May during the spawning season (P<0.05).