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Background Wild medicinal plants are suffering natural environmental stresses and habitat destruction. The genetic diversity evaluation of wild accessions and their in vitro raised genotypes using molecular markers, as well as the estimation of substances of pharmaceutical value in wild plants and their regenerated genotypes are convenient approaches to test the genetic fidelity of regenerated plants as a source of substances of pharmaceutical value. In this study, the genetic diversity of 12 accessions of the medicinal plant Achillea fragrantissima, representing five sites in the mountains of South Sinai, Egypt, were estimated by the inter simple sequence repeats (ISSR) fingerprinting and their volatile oil components were identified using gas chromatography-mass spectrometry (GC-MS) analysis. The same accessions were regenerated in vitro and the genetic diversity and volatile oil components of propagated genotypes were determined and compared to their wild parents. Results Clustering and principal component analyses indicated that the wild accessions and their regenerated genotypes were genetically differentiated, but the regenerated plants are relatively more diverse compared to their wild parents. However, genetic variation between wild accessions is inherited to their in vitro propagated genotypes indicating genotypic differentiation of the examined accessions. The number of volatile oil compounds in the wild A. fragrantissima accessions was 31 compounds while in the in vitro propagated plants only 24 compounds were detected. Four major compounds are common to both wild and regenerated plants; these are artemisia ketone, alpha-thujone, dodecane, and piperitone. Conclusions Genome profiling and essential oil components analysis showed variations in A. fragrantissima accessions from different populations. Genetic differences between wild and regenerated genotypes were analyzed and validated with the final conclusion that in vitro conditions elicited higher genetic variation that is associated with reduced amount and diversity in the essential oil components.

Root survival to flooding-induced hypoxic stress is dependent upon maintaining the functionality of the root apical meristem quiescent center (QC), a process that is governed by the basipetal flow of auxin leading to the formation of an auxin maximum, which is needed for the establishment of a highly oxidized environment specifying the QC niche. Perturbations in auxin flow and distribution along the root profile occurring during hypoxia can shift the redox state of the QC towards a more reduced environment, leading to the activation of the QC, degradation of the meristem, and root abortion. The maize phytoglobin gene ZmPgb1.1 is involved in minimizing these damaging effects during hypoxia in processes that result in sustaining the PIN-mediated auxin maximum and an oxidized environment in the QC. The oxidized environment is accomplished by maintaining the activity of redox enzymes oxidizing ascorbate and glutathione. These events, compromised in QCs suppressing ZmPgb1.1, ensure the functionality of the QC and root meristems under conditions of low oxygen, resulting in stable root performance.

Wheat is a major nutritional cereal crop that has economic and strategic value worldwide. The sustainability of this extraordinary crop is facing critical challenges globally, particularly leaf rust disease, which causes endless problems for wheat farmers and countries and negatively affects humanity’s food security. Developing effective marker-assisted selection programs for leaf rust resistance in wheat mainly depends on the availability of deep mining of resistance genes within the germplasm collections. This is the first study that evaluated the leaf rust resistance of 50 Egyptian wheat varieties at the adult plant stage for two successive seasons and identified the absence/presence of 28 leaf rust resistance (Lr) genes within the studied wheat collection. The field evaluation results indicated that most of these varieties demonstrated high to moderate leaf rust resistance levels except Gemmeiza 1, Gemmeiza 9, Giza162, Giza 163, Giza 164, Giza 165, Sids 1, Sids 2, Sids 3, Sakha 62, Sakha 69, Sohag 3 and Bany Swif 4, which showed fast rusting behavior. On the other hand, out of these 28 Lr genes tested against the wheat collection, 21 Lr genes were successfully identified. Out of 15 Lr genes reported conferring the adult plant resistant or slow rusting behavior in wheat, only five genes (Lr13, Lr22a, Lr34, Lr37, and Lr67) were detected within the Egyptian collection. Remarkedly, the genes Lr13, Lr19, Lr20, Lr22a, Lr28, Lr29, Lr32, Lr34, Lr36, Lr47, and Lr60, were found to be the most predominant Lr genes across the 50 Egyptian wheat varieties. The molecular phylogeny results also inferred the same classification of field evaluation, through grouping genotypes characterized by high to moderate leaf rust resistance in one cluster while being highly susceptible in a separate cluster, with few exceptions.

Substantial variation in phenotypic traits and ISSR fingerprinting was observed among twenty populations ofAchillea fragrantissima(Forssk.) Sch. Bip. in Egypt. Such variation was reflected in the clustering of the examined populations into two major groups: one representing populations in the mountainous area of South Sinai and the other comprising populations growing at low elevations in the middle of Sinai and the desert west of the Suez Canal from Suez in the east to Cairo in the west. Five populations in the eastern part of Sinai near Nuwieba and Taba on the Gulf of Aqaba were loosely assigned to the first group. The populations growing at high elevations in South Sinai, under lower temperature and higher humidity, were characterized by a higher number of total and polymorphic ISSR markers compared with other populations. Unique ISSR markers were more often observed in the fingerprinting of seven populations including five populations growing in the high mountains of Saint Catherine in South Sinai and two populations growing at low elevations but at Wadi Hof south-east of Cairo. Interestingly, unique bands were found in the populations that possessed traits associated with larger plant size and seed yield as well as better vigour. These are important criteria for the selection ofA. fragrantissimapopulations for conservation and sustainable commercial use.

Plants respond to hypoxic stress through either acclimation to the stress or avoidance of it, as they do to most environmental stresses. The hypothesis that has general consensus among the community is that ethylene response factors (ERFs) are central elements that control both types of responses to hypoxia. Recent studies suggest that this may not be the case for all cells experiencing hypoxic stress. Mature maize root cells undergoing hypoxic stress were found to undergo acclimation and avoidance mechanisms involving ERFs, whereas meristematic root cells and cells still undergoing differentiation acclimated to the response without the involvement of ethylene synthesis or ERFs. Phytoglobins (PGBs) and NO were demonstrated to be components critical to the acclimation response. These findings are discussed relative to the possibility that PGBs may be acting as molecular switches controlling cellular stress responses and hormonal changes and responses in cells.