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Chemosensory proteins (CSPs) are small scavenger proteins that are mainly known as transporters of pheromone/odor molecules at the periphery of sensory neurons in the insect antennae and in the producing cells from the moth female pheromone gland. Sequencing cDNAs of RNA encoding CSPs in the antennae, legs, head, pheromone gland and wings from five single individual adult females of the silkworm moth Bombyx mori showed that they differed from genomic sequences by subtle nucleotide replacement (RDD). Both intronless and intronic CSP genes expressed RDDs, although in different rates. Most interestingly, in our study the degree of RDDs in CSP genes were found to be tissue-specific. The proportion of CSP-RDDs was found to be significantly much higher in the pheromone gland. In addition, Western blot analysis of proteins in different tissues showed existence of multiple CSP protein variant chains particularly found in the pheromone gland. Peptide sequencing demonstrated the occurrence of a pleiad of protein variants for most of all BmorCSPs from the pheromone gland. Our findings show that RNA editing is an important feature in the expression of CSPs and that a high variety of RDDs is found to expand drastically thus altering the repertoire of CSP proteins in a tissue-specific manner.

V-myb avian myeloblastosis viral oncogene homolog (MYB) transcription factors play important roles in the processes of plant growth, development, and stress responses. In this study, a full-length cDNA sequence of a MYB gene, designated FvMYB1, was isolated from Arizona ash (Fraxinus velutina Torr.) for the first time. Sequence analysis showed that the deduced amino acid sequence of FvMYB1 encoded novel MYB proteins with single DNA binding domains. Based on the R3 domain amino acid sequence, the FvMYB1 was closely related to some proteins whose functions were known. The expression pattern of FvMYB1 in different organs of Arizona ash was analyzed by semiquantitative RT-PCR and real-time PCR (qRT-PCR). Results showed that this gene was widely distributed in all the tested organs and the expression level of FvMYB1 was the highest in stems and the lowest in roots. The gene expression level decreased dramatically in roots under salt treatment (300 mM, 24 h), while no obvious change was observed in stems. Subcellular localization indicated that FvMYB1 was localized in the nucleus. This study will lead to further research in resistance to abiotic stress in Arizona ash. [ABSTRACT FROM AUTHOR]

In this study, a full-length cDNA of the acyl-ACP thioesterase, AhFatA, was cloned from developing seeds of Arachis hypogaea L. by 3′-RACE. Sequence analysis showed that the open reading frame encodes a peptide of 372 amino acids and has 50-70% identity with FatA from other plants. Real-time quantitative PCR analysis revealed that AhFatA was expressed in all tissues of A. hypogaea L., but most strongly in the immature seeds harvested at 60 days after pegging. Heterologous expression of AhFatA in Escherichia coli affected bacterial growth and changed the fatty acid profiles of the membrane lipid, resulting in directed accumulation towards palmitoleic acid and oleic acid. These results indicate that AhFatA is at least partially responsible for determining the high palmitoleic acid and oleic acid composition of E. coli. [ABSTRACT FROM AUTHOR]

Late embryogenesis abundant (LEA) protein family is a large protein family that includes proteins accumulated at late stages of seed development or in vegetative tissues in response to drought, salinity, cold stress and exogenous application of abscisic acid. In order to isolate peanut genes, an expressed sequence tag (EST) sequencing project was carried out using a peanut seed cDNA library. From 6258 ESTs, 19 LEA-encoding genes were identified and could be classified into eight distinct groups. Expression of these genes in seeds at different developmental stages and in various peanut tissues was analysed by semi-quantitative RT-PCR. The results showed that expression levels of LEA genes were generally high in seeds. Some LEA protein genes were expressed at a high level in non-seed tissues such as root, stem, leaf, flower and gynophore. These results provided valuable information for the functional and regulatory studies on peanut LEA genes. [ABSTRACT FROM AUTHOR]

Five putative acyl carrier protein (ACP) cDNAs were isolated from developing peanut seeds by searching ESTs of a peanut immature-seed cDNA library and PCR-based cloning. Five peanut ACPs contained a strictly conserved Ser residue in the Asp-Ser-Leu (DSL) motif, which is an important characteristic of ACPs in plants and bacteria. Three AhACPs, AhACP1, AhACP4, AhACP5, were predicted to be located in chloroplast, while two AhACPs, AhACP2 and AhACP3, in mitochondria. Comparison of genomic DNA and cDNA sequences demonstrated three chloroplast ACPs (cpACPs) comprising of four exons and three introns while two mitochondrial ACPs (mtACPs) contained two exons and one intron. More than two homologs of each AhACP were expressed in developing peanut seeds. Most homologs were verified by corresponding genomic DNA sequences. Semi-quantitative RT-PCR analysis suggested AhACP1 was a seed-predominant ACP isoform. AhACP4 and AhACP5 showed same mRNA profile in different organs and during seed development. Two mtACPs expressed highly in peanut flower tissue which was distinct from three cpACPs. [ABSTRACT FROM AUTHOR]

Candidate genes of multisubunit (MS) and multifunctional (MF) acetyl-CoA carboxylase (ACCase) including accB1, accB2, accC, accA, accD, and MF-ACCase were isolated from peanut by sequencing a full-length cDNA library and homology-based cloning. Primary structures of peanut ACCases were highly conserved, especially biochemical function domains, compared with other higher plants and Escherichia coli. The numbers of homologs of each ACCase gene expressed in developing seed of peanut varied from two to five. Two editing sites of peanut accD were identified by comparing genomic DNA and its corresponding cDNAs. The MS-ACCase of Arachis hypogaea and Arabidopsis thaliana shared a conservative structure of gene organization. Semiquantitative reverse transcription polymerase chain reaction analysis indicated that MS-ACCase and MF-ACCase genes were expressed in all peanut tissues examined, but their mRNA expression level were quite different. In peanut seed development, accC, accA, accD, and MF-ACCase mRNAs were expressed strongly at 60 days after pegging. [ABSTRACT FROM AUTHOR]

Background: MicroRNAs (miRNAs) are a new class of small, endogenous RNAs that play a regulatory role in the cell by negatively affecting gene expression at the post-transcriptional level. miRNAs have been shown to control numerous genes involved in various biological and metabolic processes. There have been extensive studies on discovering miRNAs and analyzing their functions in model species, such as Arabidopsis and rice. Increasing investigations have been performed on important agricultural crops including soybean, conifers, and Phaselous vulgaris but no studies have been reported on discovering peanut miRNAs using a cloning strategy. Results: In this study, we employed the next generation high through-put Solexa sequencing technology to clone and identify both conserved and species-specific miRNAs in peanuts. Next generation high through-put Solexa sequencing showed that peanuts have a complex small RNA population and the length of small RNAs varied, 24- nt being the predominant length for a majority of the small RNAs. Combining the deep sequencing and bioinformatics, we discovered 14 novel miRNA families as well as 75 conserved miRNAs in peanuts. All 14 novel peanut miRNAs are considered to be species-specific because no homologs have been found in other plant species except ahy-miRn1, which has a homolog in soybean. qRT-PCR analysis demonstrated that both conserved and peanut-specific miRNAs are expressed in peanuts. Conclusions: This study led to the discovery of 14 novel and 22 conserved miRNA families from peanut. These results show that regulatory miRNAs exist in agronomically important peanuts and may play an important role in peanut growth, development, and response to environmental stress. [ABSTRACT FROM AUTHOR]

The cultivated peanut is a valuable source of dietary oil and ranks fifth among the world oil crops. Plant fatty acid biosynthesis is catalysed by type II fatty acid synthase (FAS) in plastids and mitochondria. By constructing a full-length cDNA library derived from immature peanut seeds and homology-based cloning, candidate genes of acyl carrier protein (ACP), malonyl-CoA:ACP transacylase, β-ketoacyl-ACP synthase (I, II, III), β-ketoacyl-ACP reductase, β-hydroxyacyl-ACP dehydrase and enoyl-ACP reductase were isolated. Sequence alignments revealed that primary structures of type II FAS enzymes were highly conserved in higher plants and the catalytic residues were strictly conserved in Escherichia coli and higher plants. Homologue numbers of each type II FAS gene expressing in developing peanut seeds varied from 1 in KASII, KASIII and HD to 5 in ENR. The number of single-nucleotide polymorphisms (SNPs) was quite different in each gene. Peanut type II FAS genes were predicted to target plastids except ACP2 and ACP3. The results suggested that peanut may contain two type II FAS systems in plastids and mitochondria. The type II FAS enzymes in higher plants may have similar functions as those in E. coli. [ABSTRACT FROM AUTHOR]

In the present study, genetic differentiation of Bemisia tabaci (Gennadius) biotype Q was analyzed based on mitochondrial cytochrome oxidase I (mt COI) gene sequence. The results showed that B. tabaci biotype Q could be separated into two subclades, which were labeled as subclades Q1 and Q2. Subclade Q1 was probably indigenous to the regions around the Mediterranean area and subclade Q2 to Israel or Cyprus. It was because B. tabaci was composed of several genetically distinct groups with a strong geographical association between more closely related biotypes. Not all of the B. tabaci biotype Q in the non-Mediterranean countries come from the same regions. Until now, all B. tabaci biotype Q in China were grouped into subclade Q1. The B. tabaci biotype Q introduced into the US included both subclades Q1 and Q2. The genetic structure analysis showed higher genetic variation of subclade Q1 than that of subclade Q2. [ABSTRACT FROM AUTHOR]

Making use of the gene resources of wild type peanuts is a way to increase the genetic diversity of the cultivars. Marker assisted selection (MAS) could shorten the process of inter-specific hybridization and provide a possible way to remove the undesirable traits. However, the limited number of molecular markers available in peanut retarded its MAS process. We started a peanut ESTs (Expressed Sequence Tags) project aiming at cloning genes with agronomic importance and developing molecular markers. In this study we found 610 ESTs that contained one or more SSRs from 12,000 peanut ESTs. The most abundant SSRs in peanut are trinucleotides (66.3%) SSRs and followed by dinucleotide (28.8%) SSRs. AG/TC (10.7%) repeat was the most abundant and followed by CT/GA (9.0%), CTT/GAA (7.4%), and AAG/TTC (7.3%) repeats. Ninety-four SSR containing ESTs were randomly selected for primer design and synthesis, of which 33 pairs could generate good amplification and were used for polymorphism assessment. Results showed that polymorphism was very low in cultivars, while high level of polymorphism was revealed in wild type peanuts. [ABSTRACT FROM AUTHOR]