New potential roles of StDREB1 and VvWRKY2 transcription factors in potato dormancy and sprouting patterns.

In a previous study, transgenic potato plants overexpressing the StDREB1 or the VvWRKY2 transcription factor (TF) proved to have higher productivity and ameliorated tuber quality in comparison to wildtype (WT; the BF15 variety) plants. Interestingly, when stored at 4 °C, we noticed that the tubers of transgenic potato plants exhibited a delay in sprouting, hence a longer dormancy period. Therefore, we decided to study the dormancy and sprouting of these tubers (the two transgenic and the WT lines) through a physiological and biochemical characterization. WT and genetically modified (GM) tubers were stored at 4 °C for different periods (0, 30, 90, 180, and 240 days) followed by placing them in a germination chamber and the sprouting parameters were then monitored. According to our findings, the overexpression of these two TFs led to modifications in the sprouting kinetic of tubers through an extension of the dormancy period and changes in the sprouting process. Indeed, WT tubers emitted apical and lateral sprouts while those from GM plants showed mainly apical sprouts. In addition, higher reactive oxygen species (ROS) rates, indicators of tuber aging, were recorded in WT tubers compared to GM ones. The higher antioxidant enzyme activities in GM tubers seem to be responsible for aging modification in comparison to WT. The above results suggest the first report on new roles of the StDREB1 and VvWRKY2 TF which seemed to be involved in the regulation of potato tuber aging via a reduction of the main biochemical factors concentration and the ROS content leading to a longer dormancy period and a modified sprouting pattern.

The Plant Growth-Promoting Bacteria Strain Bacillus mojavensis I4 Enhanced Salt Stress Tolerance in Durum Wheat.

Plant growth and production are adversely affected by soil salinity. A plant growth-promoting bacteria (PGPB) designated as the "I4 strain" of Bacillus mojavensis was isolated from Tunisian soil (Sfax, Tunisia) and showed the ability to be grown in the presence of NaCl concentrations ranging from 0 to 10% in Luria Bertani (LB) medium. The PGPB-mediated salt tolerance in durum wheat was evaluated. The physiological parameters such as growth, shoot and root length, dry and fresh weight were higher in I4-inoculated wheat plants in comparison with non-treated plants under salt stress. Results showed that this strain promoted wheat growth and preserved the membrane damage by notably lowering the electrolytes leakage and malondialdehyde content in contrast to non-inoculated plants. Moreover, leaf chlorophyll content, biochemical parameters and antioxidant enzyme activities measurement showed a better salt and heavy metal stress adaptation of the I4-inoculated plants. Due to these outcomes, it could be suggested that the inoculation of the PGPB I4 strain enhanced the wheat plant's growth, especially under salt stress conditions. This study confirms the ameliorative role played by PGPB in tolerating salt stress in wheat and their potential use as biofertilizers to enhance its growth in saline soil and help in promoting this plant's culture to provide food security under these perturbed global circumstances.

Heat, drought, and combined stress effect on transgenic potato plants overexpressing the StERF94 transcription factor.

Despite their economic importance worldwide, potato plants are sensitive to various abiotic constraints, such as drought and high temperatures, which cause significant losses in yields and tuber quality. Moreover, because of the climate change phenomenon, plants are frequently subjected to combined stresses, mainly high temperatures and drought. In this context, breeding for tolerant varieties should consider not only plant response to drought or high temperature but also to combined stresses. In the current study, we studied transgenic potato plants overexpressing an ethylene response transcription factor (TF; StERF94) involved in abiotic stress response signaling pathways. Our previous results showed that these transgenic plants display tolerance to salt stress more than wildtype (WT). In this work, we aimed to investigate the effects of drought, heat, and combined stresses on transgenic potato plants overexpressing StERF94 TF under in vitro culture conditions. The obtained results revealed that StERF94 overexpression improved the tolerance of the transgenic plants to drought, heat, and combined stresses through better control of the leaf water and chlorophyll contents, activation of antioxidant enzymes, and an accumulation of proline, especially in the leaves. Indeed, the expression level of antioxidant enzyme-encoding genes (CuZnSOD, FeSOD, CAT1, and CAT2) was significantly induced by the different stress conditions in the transgenic potato plants compared with the WT plants. This study further confirms that StERF94 TF may be implicated in regulating the expression of target genes encoding antioxidant enzymes.

Improved growth and tuber quality of transgenic potato plants overexpressing either NHX antiporter, CLC chloride channel, or both.

The nutritional enhancement of potato plants (Solanum tuberosum L.,) is highly critical. As it is considered a worldwide basic vegetarian nutrition to maintain health. S. tuberosum is one of the foremost staples and the world's fourth-largest food crop. In advance, its need is increasing because of its high-industrial value and population blast. To improve both potato growth and behavior under harsh environmental conditions, we produced transgenic potato plants overexpressing either VvNHX (a sodium proton antiporter from Vitis vinifera), VvCLC (a chloride channel from Vitis vinifera), or both. Control and transgenic plants were grown in greenhouse and field under non-stressed conditions for 85 days in order to characterize their phenotype and evaluate their agronomical performance. To this aim, the evaluation of plant growth parameters, tuber yields and characteristics (calibers, eye number and color), the chemical composition of tubers, was conducted and compared between the different lines. The obtained results showed that transgenic plants displayed an improved growth (flowering precocity, gain of vigor and better vegetative growth) along with enhanced tuber yields and quality (increased protein and starch contents). Our findings provide then insight into the role played by the VvNHX antiport and the VvCLC channel and a greater understanding of the effect of their overexpression in potato plants.

The pyrethroid insecticide permethrin confers hepatotoxicity through DNA damage and mitochondria-associated apoptosis induction in rat: Palliative benefits of Fumaria officinalis.

Permethrin (PER) is a pyrethroid pesticide that is extensively used as an insecticide in world because of its high activity and its low mammalian toxicity. The current study was conducted to investigate the protective action of Fumaria officinalis against PER-induced liver injury in male rats. However, HPLC-DAD showed the richness of 6 components in F. officinalis (F) including quercetin, ferulic acid, and naringenin which were the most abundant. Total polyphenols, total flavonoids, and condensed tannins were studied by phytochemical screening. In vitro, antioxidant properties showed that F. officinalis exhibited the highest DPPH radical, FRAP, and H2 O2 tests and total antioxidant capacity. Wistar rats were divided into four groups: negative control group (C), positive control group (F) (200 mg F. officinalis/kg BW), PER group (34.05 mg permethrin/kg BW), and PER + F group (34.05 mg permethrin/kg BW and 200 mg F. officinalis/kg BW). Oral administration of PER led to promote a decrease of body weight and Ca2+ -ATPases and Mg2+ -ATPases activities and an increase of plasma C-reactive protein level, transaminases, and hepatic ϒ-GT activities as well as hepatic and mitochondrial oxidative stress. An increase in plasma lactate-to pyruvate ratio and a reduction in complexes enzymes I, III, and IV activities were also observed. In addition, histoarchitecture of liver in PER-treated rats showed apoptosis and necrosis as confirmed by DNA fragmentation. F. officinalis significantly exerted hepatoprotective effect by modulating hepatic alteration and mitochondrial dysfunction as well as genotoxicity. This effect could be attributed to phenolics compounds such as polyphenols, condensed tannins, and flavonoids.

Isolation of bacterial strains from compost teas and screening of their PGPR properties on potato plants.

The beneficial effect of compost and compost tea on plant growth and protection is mainly associated with the microbial diversity and the presence of bacteria with plant growth-promoting effect. PGPR are considered as eco-friendly bio-fertilizers that may reduce the use of chemical pesticides and fertilizers. Three composts (AT, A10, and A30) were previously prepared from industrial wastes (olive mill wastewater, olive pomace, coffee ground, and phosphogypsum). In the present study, we isolated three bacterial strains from the compost teas. The phylogenetic identification of these bacterial strains (B.AT, B.A10, and B.A30) showed that they correspond to Serratia liquefaciens (B.AT and B.A10) and Achromobacter spanius (B.A30) species. A further characterization of the PGPR traits of these bacteria showed that they produce siderophore, exopolysaccharides, and IAA. Their effect on potato plant growth, yields, and tuber quality was performed under field culture conditions. Results showed that these strains can be characterized as PGPR, the best effect on potato plant growth was observed with Serratia liquefaciens (B.AT), the best yield and tuber quality was observed with Serratia liquefaciens (B.A10) while bacterial treatment with Achromobacter spanius (B.A30) is a Cd-tolerant PGPR.

Beneficial effects of Salvia officinalis essential oil on vanadium-induced testicular injury, DNA damage and histological alterations in Wistar rats.

Vanadium has been shown to catalyze the generation of reactive oxygen species. Since free radical production and lipid peroxidation are potentially important mediators in testicular physiology and pathophysiology, the present study was conducted to elucidate vanadium-induced oxidative damage in rat testis and the ameliorative role of Salvia officinalis essential oil (SEO) against the adverse effects of this heavy metal. Adult male Wistar rats were treated daily during 10 days either with ammonium metavanadate (5 mg/kg bw, intraperitoneally), SEO (15 mg/kg bw, orally) or their combination. A group of rats receiving daily a saline solution served as a negative control. Vanadium treatment induced a significant decrease in body and reproductive organ weights, serum testosterone level and sperm number and motility. An increase in lipid peroxidation and protein oxidation as well as a marked inhibition in the activities of antioxidant enzymes in the testes and seminal vesicles indicated the occurrence of oxidative stress after vanadium toxicity. Histopathological changes in testis and seminal vesicles were also observed following vanadium administration. However, co-administration of SEO to vanadium-treated rats resulted in an appreciable improvement of these parameters, emphasizing the therapeutic effects of SEO. It can be suggested that SEO mitigates vanadium-induced reproductive damage due to its antioxidant capacity. Thus, we can hypothesize that SEO supplementation could protect against vanadium poisoning.

Subacute toxicity studies of meals prepared from genetically modified potato overexpressing the StDREB1 or the VvWRKY2 transcription factor in rats.

BACKGROUND: Potato tubers from genetically modified plants overexpressing the StDREB1 or the VvWRKY2 transcription factors that exhibited improved tolerance to salt and resistance to Fusarium solani infection were characterized and evaluated for safety in a 30 day rat feeding study. Male Wistar rats were split into four groups and provided with a diet composed of 33% (w/w) of either one of the two genetically modified potatoes (GMPs), 33% of the commercial Spunta variety (Sp), or a control group fed with the basal rats' diet. The influence of the GMPs on rat behavior and overall health parameters was evaluated and compared with that of commercial potato (i.e. the Sp group) and control diet. RESULTS: Small differences were noticed in the chemical composition of the different tubers, but all the diets were adjusted to an identical caloric level. Results showed no sign of toxic or detrimental effects on the rats' overall health as a result of these diets. The rats fed with the GMPs meal showed hematological and biochemical compositions of the plasma comparable to the control groups. No histopathological damage nor any structural disorganization, severe congestion, or acute inflammation were noticed in the rats' tissues. CONCLUSION: Under these study conditions, the GMP diets did not induce any apparent or significant adverse effects on rats after 30 days of dietary administration in comparison with rats fed diets with the corresponding non-transgenic diet and the standard diet group. These two GMPs were therefore considered to be as safe as their commercial comparator. © 2022 Society of Chemical Industry.

Impact of the overexpression of the StDREB1 transcription factor on growth parameters, yields, and chemical composition of tubers from greenhouse and field grown potato plants.

Potato plants are often exposed to biotic and abiotic stresses that negatively impact their growth, development, and yield. Plants respond to different stresses by inducing large numbers of stress-responsive genes, which can be either functional or regulatory genes. Among regulatory genes, Dehydration Responsive Element Binding (DREB) genes are considered as one of the main groups of transcriptional regulators. The overexpression of these factors in several transgenic plants leads to enhancement of abiotic stress tolerance. However, a number of reports showed that the overexpression of DREB factors under control of constitutive promoter, affects their morphology and production. Therefore, it becomes interesting to evaluate the effect of the overexpression of this StDREB1 transcription factor on plant growth, morphology, yield and tuber composition under both greenhouse and field culture conditions. To our knowledge, there is no available data on the effect of DREBA-4 overexpression on potato plants morphology and yield. Indeed, most studies focused on DREB genes from A-1 and A-2 groups for other plant species. Our results showed that StDREB1, a A-4 group of DREB gene from potato (Solanum tuberosum L.), overexpressing plants did not show any growth retardation. On the contrary, they seem to be more vigorous, and produced higher tuber weight in greenhouse and field culture than the wild type (WT) plants. Moreover, the overexpression of StDREB1 transcription factor seemed to have an effect on tuber quality in terms of dry matter, starch contents and reducing sugars in comparison to the WT tubers. These data suggest that the StDREB1 gene from A-4 group of DREB subfamily can be a good candidate in potato breeding for stress tolerance.