Search

Kosteletzkya virginica is a halophyte species which could be used for production of industrial raw material such as biodiesel and for developing ecologically sound saline agriculture as well as for tideland soil improving. Using Rapid Amplification of cDNA Ends (RACE) method, a 1610 bp cDNA of stearoyl-ACP desaturase (SAD) gene containing a 1188 bp complete open reading fragment (ORF) was firstly isolated from seeds of K. virginica. Sequence analysis revealed that the nucleotide sequence of K. virginica SAD had a high level of homology to SAD from Gossypium hirsutum, but had relative low identity to SAD from other pants. However, K. virginica SAD had a high level of amino acid sequence homology to SAD from other plants. Characteristics of the deduced protein were predicted and analyzed using bioinformatic methods. Expression analysis via real-time PCR indicated that expression levels of the SAD gene were markedly distinct in different K. virginica tissues and different development stage seeds. The results of the expression analysis in this study, combined with existing research, suggest that SAD may be involved in the regulation of plant seed growth and development. These results serve as a foundation for further studies of the mechanisms regulating SAD gene expression and could eventually lead to the development of higher quality K. virginica varieties.

β-ketoacyl-ACP synthetase II (KAS II) which catalyzes the elongation of 16:0-ACP to 18:0-ACP，determines the ratio of palmitic acid (16:0) to stearic acid (18:0). Using Rapid Amplification of cDNA Ends (RACE) and a peanut cDNA library we had previously constructed, we isolated a 1867bp cDNA of the KAS II gene containing a 1212bp complete open reading fragment (ORF). Sequence analysis revealed that peanut KAS II had a high level of nucleotide and amino acid sequence homology to KAS II from other plants. Phylogenetic analysis showed that KAS II from plants, bacteria and virus were grouped into different clades respectively suggesting the independent evolution of KAS II from different sources. Characteristics of the deduced protein were predicted and analyzed using bioinformatic methods. The protein was predicted as stable and hydrophobic with molecular weight of 43181.4 and theoretical PI of 5.69. Expression analysis by real-time PCR indicated that expression levels of KAS II gene were markedly distinct in different peanut tissues and varieties. The expression analysis in this study combined with existing researches suggested KAS II may be involved in the regulation of plant growth and development.

Acetyl-CoA carboxylase (ACCase; EC 6.4.1.2) catalyzes the synthesis of malonyl-CoA, the first intermediate in fatty acid synthesis. Genes for multi-functional acetyl-CoA carboxylase and two subunits of multi-subunit acetyl-CoA carboxylase, biotin carboxylase and β-Carboxyltransferase, have been cloned from peanut. The ORF of the three proteins are 6783bp, 1623bp, 1479 bp in length, encoding 2260, 540, 492 amino acids, respectively. The predicted amino acid sequences of the multi-functional AhACCase and AhBC from peanut shared high sequence identity, 90.9% and 88%, to the corresponding Glycine max proteins, respectively, while the amino acid sequence of AhβCT gene showed 71.6% identity with that from Nothofagus gunnii. Phylogenetic analysis showed that all of these three genes from peanut were grouped into the big branch of proteins from higher plant. Moreover, observation of the tree revealed that multi-functional ACCase genes may arise by independent gene duplication events in green algae and higher plants branches, and the biotin carboxylase and β-Carboxyltransferase genes from cyanobacteria may be the origin of genes from higher plants, mosses and eukaryotic algae.

The plant C2H2-type zinc finger proteins play important roles in plant tolerance to abiotic stresses. In this study, we isolated the full-length cDNA of a C2H2-type zinc finger protein gene AhZFP1 from peanut (Arachis hypogaea L.). AhZFP1 encodes a 24.75kDa protein with two C2H2-type zinc finger domains. Phylogenetic analysis showed that the AhZFP1 was close to Arabidopsis zinc finger protein AZF2. The semi-quantitative RT-PCR assay revealed that the expression of AhZFP1 was induced by salt stress in peanut roots, stems and leaves. AhZFP1 was the first C2H2-type zinc finger protein gene reported in peanut.