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Dioecism has always been an issue in many plant species with its numerous disadvantages, especially in woody trees such as date palms. As one of the most important crops in the Middle Eastern countries, researchers are having problems identifying of sex of the plant in its early stages of development. Hence, proper population stands in the male: female ratio for maintenance is almost impossible in the field for better production. In this study, sex determination of date palm (Phoenix dactilyfera L.) were identified in regions of the Y chromosome (Date-SRY) gene, the pivotal gene that initiates sex determination, using a new technique and thus an economically desirable objective, which will significantly impact profits in seed based cultivations. Partial sequences of the Date-SRY were taken and amplified by nested polymerase chain reaction (PCR). According to the results, the exact sex of date palm was identified in all the tested plants, while amplified regions of the Date-SRY gene closely matched with the human and papaya sequences. In addition, a primer pair was designed to amplify the sequences of the SRY-date gene with confidence that it will identify male date palms. These primer sequences include SRY-date Forward 5′- cggccctctaagtatctgtgcgcaacg-3′ (SRY-date F) and the SRY-date Reverse 5′- gtttgcacttcgaagcagag-3′ (SRY-date R). The complete sequence of the DNA has been registered and deposited in GenBank (BankIt1598036 DPSRY1 KC577225 thenKJ873056).

Background Salinity is a serious factor limiting the productivity of agricultural plants. One of the potential problems for plants growing under saline conditions is the inability to up take enough K+. The addition of K+ may considerably improve the salt tolerance of plants grown under salinity. It is assumed that increasing the K+ supply at the root zone can ameliorate the reduction in growth imposed by high salinity. The present study aims to determine whether an increase in the K/Na ratio in the external media would enhance the growth of date palm seedlings under in vitro saline conditions.Methods Date palm plants were grown at four concentrations of Na + K/Cl (mol/m3) with three different K/Na ratios. The 12 salt treatments were added to modified MS medium. The modified MS medium was further supplemented with sucrose at 30 g/l.ResultsGrowth decreased substantially with increasing salinity. Growth expressed as shoot and root weight, enhanced significantly with certain K/Na ratios, and higher weight was maintained in the presence of equal K and Na. It is the leaf length, leaf thickness and root thickness that had significant contribution on total dry weight. Na+ contents in leaf and root increased significantly increased with increasing salinity but substantial decreases in Na+ contents were observed in the leaf and root with certain K/Na ratios. This could be attributed to the presence of a high K+ concentration in the media. The internal Na+ concentration was higher in the roots in all treatments, which might indicate a mechanism excluding Na+ from the leaves and its retention in the roots. K/Na ratios up to one significantly increased the leaf and root K+ concentration, and it was most pronounced in leaves. The K+ contents in leaf and root was not proportional to the K+ increase in the media, showing a high affinity for K+ uptake at lower external K+ concentrations, but this mechanism continues to operate even with high external Na+ concentrations.ConclusionIncreasing K/Na ratios in the growing media of date plam significantly reduced the absorption of Na+ less than 200 mM and also balance ions compartmentalization.

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Plant response to salt stress and the mechanism of salt tolerance have received major focus by plant biology researchers. Biotic stresses cause extensive losses in agricultural production globally, but abiotic stress causes significant increase in the methylglyoxal (MG) level of GlyoxalaseI (Gly I). Identification of salt-tolerant genes when characterizing their phenotypes will help to identify novel genes using polymerase chain reaction (PCR) to amplify the DNA coding region for glyoxalase I. This method is specific, requiring only genomic DNA and two pairs of PCR primers, and involving two successive PCR reactions. This method was used rapidly and easily identified glyoxalase I sequences as salt-tolerant genes from Jojoba (Simmondsia chinensis (Link) Schneider). In the present study, the glyoxalase I gene was isolated, amplified by PCR using gene-specific primers and sequenced from the jojoba plant, then compared with other glyoxalase I sequences in other plants and glyoxalase I genes like in Brassica napus, ID: KT720495.1; Brassica juncea ID: Y13239.1, Arachis hypogaea; ID: DQ989209.2; and Arabidopsis thaliana L, ID: AAL84986. The structural gene of glyoxalase I, when sequenced and analyzed, revealed that the uninterrupted open reading frame (ORF) of jojoba Gly I (Jojo-Gly I) spans 775 bp, corresponding to 185 amino acid residues, and shares 45.2% amino acid sequence identity to jojoba (Jojo-Gly I). The cloned ORF, in a multicopy constitutive expression plasmid, complemented the Jojo-Gly I, confirming that the encoded Jojo-Gly I in jojoba showed some homology with other known glyoxalase I sequences of plants.

The present work aimed at 1) characterization of the E1 and E2 proteins (HCV-E) from an Egyptian hepatitis C virus genotype 4a (HCV-4a) isolate at the molecular and immunological level, 2) in silico identification of the B- and T-cell epitopes responsible for the immunogenicity of HCV-E, and 3) evaluation of the diagnostic potential of both the recombinant HCV-E and antibodies raised using mammalian expression constructs encoding the protein. The region encoding the E1 and E2 proteins was amplified by RT-PCR from RNA isolated from blood of a human infected with HCV-4 and cloned into the pSC-TA plasmid, and the sequence was verified and used to construct a neighbor-joining phylogenetic tree. The translated nucleotide sequence was used to predict the HCV-E secondary structure using the PREDICT-PROTEIN server and PSI-PRED. A 3D model of HCV-E was generated using the online tool 3Dpro. B- and T-cell epitopes were predicted using the online tools BCPred and Epijen v1.0, respectively. The HCV-E-encoding sequence was later subcloned into the mammalian expression plasmid pQE, and the constructs that were generated were used to immunize mice in the absence and presence of adjuvants of plant origin. The maximum sequence identity obtained by nucleotide and protein BLAST analysis with previously published HCV-E sequences was 85 and 77 %, respectively. The B-cell epitope CFTPSPVVV at position 203 and the T-cell epitope ALSTGLIHL at position 380 were found to be highly conserved among all HCV genotypes. Both ELISA and Western blotting experiments on crude and purified recombinant HCV envelope proteins using mouse antisera raised using the HCV-E mammalian expression construct confirmed the specific antigenicity of the expressed protein. The antibodies raised in mice using the HCV-E-encoding construct could efficiently capture circulating antigens in patients' sera with good sensitivity that correlated with liver enzyme levels (r = 0.4052, P < 0.0001 for ALT; r = -0.5439, P = 0.0019 for AST). Moreover, combining the HCV-E-encoding construct with extracts prepared from Echinacea purpurea and Nigella sativa prior to immunizing mice significantly (P < 0.05) increased both the humoral (14.9- to 20-fold increase in antibodies) and the cellular (CD4(+) and cytotoxic CD8(+)- T lymphocytes) responses compared to mice that received the DNA construct alone or PBS-treated mice. Both recombinant HCV-E protein preparations and antibodies raised using the HCV-E-encoding mammalian expression construct represent useful diagnostic tools that can report on active HCV infection. Also, the immunostimulatory effects induced by the two plant extracts used at the cellular and humoral level highlight the potential of natural products for inducing protection against HCV infection. The neutralizing capacity of the induced antibodies is a subject of future investigations. Furthermore, the predicted B- and T-cell epitopes may be useful for tailoring future diagnostics and candidate vaccines against various HCV genotypes.

Date palm (Phoenix dactylifera L.) is the sweetest edible fruit plant in the Kingdom of Saudi Arabia. The development of precise DNA fingerprints to identify cultivar's genetic diversity is most important for breeding programs. Genotypic variation among five different cultivars of date palm of the Al Ahsa governorate in Kingdom of Saudi Arabia was studied using random amplified polymorphic DNA (RAPD) markers by QIAxcel electrophoresis system. We test 20 RAPD primers among them 15 primers show banding pattern. We use clean younger leaves that had been gathered and grind with liquid nitrogen into a fine powder and used for extraction and ultimately the quality of the DNA. We examined the DNA extraction with the use of guide CTAB and automatic Qiagen EZ1 technique and tested using the UV gel electrophoresis the concentration of the DNA became examined with LABTRON Nano spectrophotometer. Four primers gave high levels of bands with numerous polymorphisms and multiple bands. A total of 165 bands were observed, including 89 polymorphisms and 4 monomorphisms. The Rz breed is very closely related to Kh, but the recorded Rz and Shb breeds retain a high degree of genetic divergence between Ht and Sh. The results of this study demonstrate that polymorphisms revealed using RAPD markers are genotype appropriate.

Transient expression of foreign genes in plant tissue is a valuable tool for testing the efficacy of transformation methods. In this work, we present, for the first time, the utilization of agroinjection as an efficient transformation system for gene delivery in date palm fruit. The research utilized Agrobacterium tumefaciens strain LBA4404 harboring the binary vector pRI201-AN-GUS carrying the beta-glucuronidase (GUS) gene, under the control of a CaMV 35S and kanamycin (NPTII) as an antibiotic gene under the control of a NOS promoter. Based on histochemical assay of agroinjected fruit for the GUS gene expressions, this protocol has proved to be an efficient and reliable tool for transgene expression in date palm. PCR for plasmid DNA, extracted from the transformed Agrobacterium, demonstrated the generation of the expected amplicon, corresponding to the GUS gene using GUS primers.