Abscisic acid crosstalk with auxin and ethylene in biosynthesis and degradation of inulin-type fructans in chicory.

The effect of different hormones on fructan accumulation and the genes regulating biosynthesis and degradation is known; however, information on hormonal interaction mechanisms for fructan content and mean degree of polymerization (mDP) is limited. Cell suspension cultures of chicory were prepared and treated with abscisic acid (ABA), auxin (AUX), ethylene (ETH), ABA + AUX or ABA + ETH, then inulin concentration, mDP of inulin and expression of FAZY genes was determined. A low concentration of AUX and ETH increased fructan content, while a high concentration of AUX and ETH decreased it. Exogenous ABA increased mDP of inulin and this coincided with the low expression of 1-FEHII. In hormone interactions, ABA changed and adjusted the effect of both AUX and ETH. ABA, together with a low level of AUX and ETH, resulted in a decrease in inulin content and increase in mDP, which coincided with low expression of FEHII. ABA together with a high level of AUX and ETH caused an increase in inulin content with a lower mDP, which coincided with high expression of biosynthesis (1-FFT) and degradation (1-FEHII) genes. The effect of both AUX and ETH was almost the same, although the effect of ETH was more severe. ABA had a modulating role in combinations with AUX and ETH. Among biosynthesis and degradation genes, the expression of 1-FEHII was more affected by these hormones.

Phyto-miRNAs-based regulation of metabolites biosynthesis in medicinal plants.

Medicinal plants, are known to produce a wide range of plant secondary metabolites (PSMs) applied as insecticides, drugs, dyes and toxins in agriculture, medicine, industry and bio-warfare plus bio-terrorism, respectively. However, production of PSMs is usually in small quantities, so we need to find novel ways to increase both quantity and quality of them. Fortunately, biotechnology suggests several options through which secondary metabolism in plants can be engineered in innovative ways to: 1) over-produce the useful metabolites, 2) down-produce the toxic metabolites, 3) produce the new metabolites. Among the ways, RNA interference (RNAi) technology which involves gene-specific regulation by small non-coding RNAs (sncRNAs) have been recently emerged as a promising tool for plant biotechnologist, not only to decipher the function of plant genes, but also for development of the plants with improved and novel traits through manipulation of both desirable and undesirable genes. Among sncRNAs, miRNAs have been recorded various regulatory roles in plants such as development, signal transduction, response to environmental stresses, metabolism. Certainly, the use of miRNAs in metabolic engineering requires identification of miRNAs involved in metabolites biosynthesis, understanding of the biosynthetic pathways, as well as the identification of key points of the pathways in which the miRNAs have their own effect. Thus, we firstly consider these three issues on metabolic engineering of medicinal plants. Our review shows, application of miRNAs can open a novel perspective to metabolic engineering of medicinal plants.

Phyto-miRNA: A molecule with beneficial abilities for plant biotechnology.

The discovery of the phenomenon of gene silencing in 1990s opened new doors to biotechnology and plant breeding in order to supply food security. Food Security, as defined by FAO, it exists when all people, at all times, have economic access to safe, sufficient and nutritious food to meet their dietary needs and food preferences for a healthy and active life. Due to the need to ensure food security and also gene silencing potentials, research in this field began with astonishing speed and even it still continues. In this field, miRNA-associated gene silencing especially attracted the attention of scientists in order to decrypt the genes involved in process such as plant growth and development, metabolism, signal transduction, response against environmental stresses, nodule development in legumes and inducement male sterility. In addition, miRNA found a lot of applications in plant biotechnology like miRNA-based molecular markers and miRNA-based molecular breeding for plants improvement. Given to the growing importance of plant miRNAs (Phyto-miRNAs) in biotechnology and expansion of their applications in molecular breeding, it is necessary to review miRNA in an up-to-date schema. In this study, it was presented both the necessary foundations of miRNAs and their important uses in plant sciences, such as molecular markers and metabolic engineering. As a result, we hope to expand the use of artificial miRNAs in plants engineering.

Bulked segregant analysis for relative water content to detect quantitative trait loci in wheat under drought stress.

This study was carried out to evaluate the genetic effect of quantitative trait loci (QTLs) conferring drought tolerance in wheat. A population of 120 F(2) individuals from the cross between the drought-tolerant S-78-11 and drought-sensitive Tajan cultivars were analyzed for their segregation under drought stress conditions. The relative water content under drought stress conditions exhibited continuous variation, indicating the minor gene effects on the trait. Single-marker analysis (SMA) was carried out to detect the main QTL association with drought tolerance. The SMA results revealed that the simple sequence repeat markers GWM182 and GWM292 on chromosome 5D and GWM410 on chromosome 5A exhibited significant association with drought tolerance, accounting for 30, 22, and 21% of the total variation, respectively. The 3 genetic loci, especially GWM182, can be used in marker-assisted selection methods in drought tolerance breeding in wheat.

Isolation and characterization of polymorphic microsatellite loci from the water mite Hygrobates fluviatilis (Acari: Hydrachnidia: Hygrobatidae).

We developed and characterized 13 microsatellite markers from the water mite Hygrobates fluviatilis. The genotypes of 32 diploid females were assessed, and all of the loci were polymorphic. The number of alleles per locus ranged from two to 21, and the observed heterozygosity ranged from 0.063 to 0.813. These microsatellite markers are the first published for water mites and will contribute to research on the population structure of this widespread species.

Multivariate analysis of morphological variation in accessions of Aegilops crassa from Iran.

Principal component and cluster analyses were used to evaluate the pattern of morphological variation in 122 accessions of Aegilops crassa for 14 quantitative characters. With the principal component analysis, the first five principal components with eigenvalues more than 1 contributed 69.5% of the variability amongst accessions, whereas PC6 to PC14 were less than unity. Plant height, stem diameter, spike length and number of spikelets per spike were the most important characters in the first principal component. The germplasm was grouped into five clusters using cluster analysis. Although each cluster had some specific characteristics of its own, but clusters were not clearly separated when plotted by the first two principal components. Mahalanobis distances (D2) determined that plant height, stem diameter, spike length, number of spikelets per spike, node width, seed length, seed width and flowering date characters as the most important characters in differentiating the accessions. The morphological variation of Aegilops crassa accessions obtained in this study provides useful information for the future collection and makes these genetic resources more accessible to breeders.

Genetic variation of jointed goatgrass (Aegilops cylindrica Host.) from Iran using RAPD-PCR and SDS-PAGE of seed proteins.

Genetic variation of 28 populations of jointed goatgrass (Aegilops cylindrica Host.), collected from different parts of Iran, were evaluated using both RAPD-PCR and SDS-PAGE of seed proteins. The diversity within and between populations for the three-band High Molecular Weight (HMW) subunits of glutenin pattern were extremely low. Out of 15 screened primers of RAPD, 14 primers generated 133 reproducible fragments which among them 92 fragments were polymorphic (69%). Genetic similarity calculated from the RAPD data ranged from 0.64 to 0.98. A dendrogram was prepared on the basis of a similarity matrix using the UPGMA algorithm and separated the 28 populations into two groups. Confusion can happen between populations with the same origin as well as between populations of very diverse geographical origins. Our results show that compare to seed storage protein, RAPD is suitable for genetic diversity assessment in Ae. cylindrica populations.