Genome-Wide Association Study (GWAS) and genome prediction of seedling salt tolerance in bread wheat (Triticum aestivum L.).

BACKGROUND: Salinity tolerance in wheat is imperative for improving crop genetic capacity in response to the expanding phenomenon of soil salinization. However, little is known about the genetic foundation underlying salinity tolerance at the seedling growth stage of wheat. Herein, a GWAS analysis was carried out by the random-SNP-effect mixed linear model (mrMLM) multi-locus model to uncover candidate genes responsible for salt tolerance at the seedling stage in 298 Iranian bread wheat accessions, including 208 landraces and 90 cultivars. RESULTS: A total of 29 functional marker-trait associations (MTAs) were detected under salinity, 100 mM NaCl (sodium chloride). Of these, seven single nucleotide polymorphisms (SNPs) including rs54146, rs257, rs37983, rs18682, rs55629, rs15183, and rs63185 with R2 ≥ 10% were found to be linked with relative water content, root fresh weight, root dry weight, root volume, shoot high, proline, and shoot potassium (K+), respectively. Further, a total of 27 candidate genes were functionally annotated to be involved in response to the saline environment. Most of these genes have key roles in photosynthesis, response to abscisic acid, cell redox homeostasis, sucrose and carbohydrate metabolism, ubiquitination, transmembrane transport, chromatin silencing, and some genes harbored unknown functions that all together may respond to salinity as a complex network. For genomic prediction (GP), the genomic best linear unbiased prediction (GBLUP) model reflected genetic effects better than both bayesian ridge regression (BRR) and ridge regression-best linear unbiased prediction (RRBLUP), suggesting GBLUP as a favorable tool for wheat genomic selection. CONCLUSION: The SNPs and candidate genes identified in the current work can be used potentially for developing salt-tolerant varieties at the seedling growth stage by marker-assisted selection.

Genetic diversity analysis in a mini core collection of Damask rose (Rosa damascena Mill.) germplasm from Iran using URP and SCoT markers.

BACKGROUND: Rosa damascena Mill is a well-known species of the rose family. It is famous for its essential oil content. The aim of the present study was to assess the genetic diversity and population structure of a mini core collection of the Iranian Damask rose germplasm. This involved the use of universal rice primers (URP) and start codon targeted (SCoT) molecular markers. RESULTS: Fourteen URP and twelve SCoT primers amplified 268 and 216 loci, with an average of 19.21 and 18.18 polymorphic fragments per primer, respectively. The polymorphic information content for URR and SCoT primers ranged from 0.38 to 0.48 and 0.11 to 0.45, with the resolving power ranging from 8.75 to 13.05 and 9.9 to 14.59, respectively. Clustering was based on neighbor-joining (NJ). The mini core collection contained 40 accessions and was divided into three distinct clusters, centered on both markers and on the combination of data. CONCLUSION: Cluster analysis and principal coordinate analysis were consistent with genetic relationships derived by STRUCTURE analysis. The findings showed that patterns of grouping did not correlate with geographical origin. Both molecular markers demonstrated that the accessions were not genetically diverse as expected, thereby highlighting the possibility that gene flow occurred between populations.

Effects of methyl jasmonate and phloroglucinol on thebaine and sanguinarine production in cell suspension culture of Persian poppy (Papaver bracteatum Lindl.).

The biosynthesis path engineering could be very promising for mass production of alkaloids by applying elicitors in the cell suspension culture of Persian poppy (Papaver bracteatum Lindl.). In this work, the effects of different concentrations of methyl jasmonate (MJ) and phloroglucinol (PG) on thebaine and sanguinarine productions in vitro were investigated. Roots as explant and supplementing 3 mg L-1 2,4-Dichlorophenoxyacetic acid with 0.5 mg L-1 Benzyl amino purine to modified MS medium were selected to achieve the most efficient combination for callus induction and production of callus fresh and dry weights. At 48 h after treatment, the addition of PG and MJ individually and in combination together significantly increased both thebaine and sanguinarine contents than the control. The results of high-performance liquid chromatography (HPLC) detection indicated that the highest production rate has been achieved through a synergic effect of two elicitors after 48 h. Results revealed that adding 200 µM of MJ and 100 mg L-1 PG increased thebaine and sanguinarine contents by 56.36 and 107.71-fold than control cells, respectively.

Anti-cancer activity of pegylated liposomal trans-anethole on breast cancer cell lines MCF-7 and T47D.

OBJECTIVE: To examine the role of liposomes for the encapsulation of drugs and their suitability for chemotherapy of breast cancer. RESULTS: Pegylated liposomal trans-anethole nanoparticles were synthesized through a reverse-phase evaporation technique. Nanoparticles were characterized in terms of mean diameter, size distribution, zeta potential, encapsulation and drug loading efficiency, drug release pattern and cytotoxicity effects. Size and zeta potential of pegylated nanoliposomal drug and blank pegylated nanoliposomal were 257 nm and -28 mV; 35.7 nm and -21 mV, respectively. Encapsulation and drug loading efficiency were 78 ± 2.5 and 2.3 ± 4.1 %, respectively. There was a 57 % release of trans-anethole from pegylated liposomal nanoparticles in 48 h. Compared to free drug, toxicological studies indicated around 9- and 8-fold cytotoxicity effect against MCF-7 and T47D cell lines respectively. CONCLUSIONS: PEG-liposomes provided a high stability and slow release of trans-anethole in two cancer cell lines.

WRR4, a broad-spectrum TIR-NB-LRR gene from Arabidopsis thaliana that confers white rust resistance in transgenic oilseed Brassica crops.

White blister rust caused by Albugo candida (Pers.) Kuntze is a common and often devastating disease of oilseed and vegetable brassica crops worldwide. Physiological races of the parasite have been described, including races 2, 7 and 9 from Brassica juncea, B. rapa and B. oleracea, respectively, and race 4 from Capsella bursa-pastoris (the type host). A gene named WRR4 has been characterized recently from polygenic resistance in the wild brassica relative Arabidopsis thaliana (accession Columbia) that confers broad-spectrum white rust resistance (WRR) to all four of the above Al. candida races. This gene encodes a TIR-NB-LRR (Toll-like/interleukin-1 receptor-nucleotide binding-leucine-rich repeat) protein which, as with other known functional members in this subclass of intracellular receptor-like proteins, requires the expression of the lipase-like defence regulator, enhanced disease susceptibility 1 (EDS1). Thus, we used RNA interference-mediated suppression of EDS1 in a white rust-resistant breeding line of B. napus (transformed with a construct designed from the A. thaliana EDS1 gene) to determine whether defence signalling via EDS1 is functionally intact in this oilseed brassica. The eds1-suppressed lines were fully susceptible following inoculation with either race 2 or 7 isolates of Al. candida. We then transformed white rust-susceptible cultivars of B. juncea (susceptible to race 2) and B. napus (susceptible to race 7) with the WRR4 gene from A. thaliana. The WRR4-transformed lines were resistant to the corresponding Al. candida race for each host species. The combined data indicate that WRR4 could potentially provide a novel source of white rust resistance in oilseed and vegetable brassica crops.

Screening of sugar beet tissue culture clones for resistance to rhizomania disease.

In this study, sugar beet tissue culture clones were used to screen rhizomania resistant genotypes. At first, explants derived from shoot tips of sugar beet seedlings were transferred to shoot tip elongation media after surface sterilization. Then, the grown shoots were transferred to media containing various hormonal combinations NAA, BA, IBA and GA3 for multiplication, growth and rooting. Later, the clones were transferred to soil-peatmoss mixture were adapted to greenhouse conditions. For screening clones against rhizomania, the genotypes of adapted clones were selected and inoculated to rhizomania-infested soil. This experiment was in a randomized complete block design with three replicates (three inoculation times) in greenhouse. Adapted plants were transferred to the soil containing rhizomania virus. All infested soils were diluted 3 to 7 with sand. After two months, infested plants were examined by DAS-ELISA test also optical densities of the samples were analyzed by SAS program. Significant differences among genotypes and blocks were observed. Genotypes were classified to few groups (ranked from completely susceptible to completely resistant). The difference between blocks was because of difference of inoculation time temperature. Use of clones of each genotype caused an increase in selection accuracy of resistant genotypes. By use of this method, chance of escaping from inoculation factor decrease and researchers can determine to be resistance of plants with high level of confidence and apply in breeding programs.

Evaluation of genetic diversity in Aegilops tauschii accessions using morphological and AFLP markers.

Thirty two accessions of Aegilops tauschii were used to assess its genetic diversity by morphological and AFLP data and to evaluate relationship between morphological and AFLP markers. Thirty AFLP primer combinations led to the amplification of fragments ranging from 50 to 500 bp of which, 97 were polymorphic across the 32 accessions. Although both AFLP and morphological data classified accessions in two groups, one possessing subsp. tauschii accessions and the other contained all accessions of subsp. strangulata with some accessions from the subsp. tauschii. This may be explained by intermediate and hybrid forms between these two subspecies. Comparison of UPGMA dendrograms of morphological and AFLP markers using the cophenetic correlation indicated a non significant correlation (r = 0.37). Nevertheless, AFLP and selected morphological characters appear as useful and complementary techniques for evaluation of genetic diversity in subspecies of A. tauschii.

Effects of different hormonal treatments on the callus production and plantlet regeneration in saffron (Crocus sativus L.).

Saffron (Crocus sativus L.) is one of valuable and native plants in the land of Iran. By this investigation the best hormonal compositions for callus production from protoplast and for plantlet regeneration from callus were determined. To isolate protoplasts, the embryogenic calli were used. The embryogenic calli were immersed in enzymatic solution to degrade the cell walls. The treated mixture was filtered and then centrifuged at 100 g for 3-5 min and the resulted pellet was rinsed. After one step of washing and another step of centrifugation, the protoplasts were gently mixed with sterile sodium alginate solution and added to MS broth consisting 1% calcium chloride and 0.3 M manitol to form calcium alginates granules. The protoplast-containing granules were exposed to MS broth including 0.3 M manitol and various treatments of two kinds of auxins (2, 4-D and NAA) and three kinds of cytokinins (2ip, Kin, BAP), respectively in four rates of 0.1, 0.2, 0.5, 1.0 mg L(-1) for auxins and in three rates of 0.1, 0.2 and 0.5 mg L(-1) for cytokinins, incubated in dark at 22 +/- 2 degrees C for a period of 30 days. Out of all the treatment of 2, 4-D (1.0 mg L(-1)) and Kin (0.2 mg L(-1)) was the best in callus induction. In order to regenerate plantlets, the resulted calli were transferred to MS broth amended with different rates of ABA (0.0, 0.5, 1.0, 1.5, 2.0 and 2.5 mg L(-1)) so that they could pass the steps of embryonic maturation. The mature embryos were transferred to MS media with different rates of GA3 (0.0, 5.0, 15.0, 20.0, 25.0 and 30.04 mg L(-1)) to initiate germination. The germinated embryos were then placed in solid MS media with various rates of NAA and 2, 4-D auxins (0.0, 0.5, 1.0 and 2.0 mg L(-1)) and different levels of BAP and Kin cytokinins (0.0, 0.5, 1.0 mg L(-1)). Results from statistical analyses indicated the treatment of NAA and BAP (each 1 mg L(-1)) as the best hormonal treatment for the plantlet regeneration from the domestic saffron calli.