Elevated CO2 ameliorate the negative effects of high temperature on groundnut (Arachis hypogaea)- Studies under free-air temperature elevation

Four groundnut (Arachis hypogaea L.) genotypes- Narayani, Dharani, K-6 and K-9 were assessed for growth and yield responses at elevated temperature of 3.0 ± 0.5°C above ambient canopy temperature (eT) and its interaction with elevated CO of 550 ± 50ppm (eT+eCO ) under Free Air 2 2 Temperature Elevation (FATE) facility. The study revealed that eT significantly decreased photosynthetic rate (A ) of all groundnut genotypes whereas eT+eCO condition ameliorated the ill effects of eT. The net 2 impact of eT on A was higher than transpiration rate (Tr) and this reflected in decreased WUE with all net genotypes. WUE improved significantly at eT+eCO with increased A and decreased Tr. Increase in 2 net canopy temperature (eT) resulted decreased relative water content (RWC), cell membrane stability and increased osmotic potential, Malondialdehyde (MDA) content and accumulation of proline. Elevated CO 2 along with eT (eT+eCO ) facilitated these parameters to recover to that of ambient controls, revealing the 2 ameliorative effect of eCO . Similar responses were recorded for biomass and yield parameters. Among 2 the selected groundnut genotypes, superior performance for seed yield at high temperature of >40°C by K-9 was due to ability to maintain better reproductive capacity and Dharani was responsive to elevated CO even at high temperature, indicating the genotypic variability.

Kernel Water Relations and Kernel Filling Traits in Maize (Zea mays L.) Are Influenced by Water-Deficit Condition in a Tropical Environment

Water deficit is a major limiting condition for adaptation of maize in tropical environments. The aims of the current observations were to evaluate the kernel water relations for determining kernel developmental progress, rate, and duration of kernel filling, stem reserve mobilization in maize. In addition, canopy temperature, cell membrane stability, and anatomical adaptation under prolonged periods of pre- and post-anthesis water deficit in different hybrids was quantified to support observations related to kernel filling dynamics. In this context, two field experiments in two consecutive years were conducted with five levels of water regimes: control (D1), and four water deficit treatments [V10 to V13 (D2); V13 to V17 (D3); V17 to blister stage (D4); blisters to physiological maturity (D5)], on three maize hybrids (Pioneer 30B80, NK 40, and Suwan 4452) in Expt. 1. Expt. 2 had four water regimes: control (D1), three water deficit treatments [V10 to anthesis (D2); anthesis to milk stage (D3); milk to physiological maturity (D4)], and two maize hybrids (NK 40 and Suwan 4452). Water deficit imposed at different stages significantly reduced maximum kernel water content (MKWC), kernel filling duration (KFD), final kernel weight (FKW), and kernel weight ear–1 while it increased kernel water loss rate (KWLR), kernel filling rate (KFR), and stem weight depletion (SWD) across maize hybrids in both experiments. The lowest MKWC under water deficit was at D3 in both experiments, indicating that lower KFR results in lowest FKW in maize. Findings indicate that the MKWC (R2 = 0.85 and 0.41) and KFR (R2 = 0.62 and 0.37) were positively related to FKW in Expt. 1 and 2, respectively. The KFD was reduced by 5, 7, 7, and 11 days under water deficit at D3, D4 in Expt. 2 and D4, D5 in Expt. 1 as compared to control, respectively. Water deficit at D5 in Expt. 1 and D4 in Expt. 2 increased KWLR, KFR, and SWD. In Expt. 2, lower canopy temperature and electrical conductivity indicated cell membrane stability across water regimes in NK 40. Hybrid NK 40 under water deficit had significantly higher cellular adaptation by increasing the number of xylem vessel while reducing vessel diameter in leaf mid-rib and attached leaf blade. These physiological adjustments improved efficient transport of water from root to the shoot, which in addition to higher kernel water content, MKWC, KFD, KFR, and stem reserve mobilization capacity, rendered NK 40 to be better adapted to water-deficit conditions under tropical environments.

Discovery of Aminoglycosides as First in Class, Nanomolar Inhibitors of Heptosyltransferase I

A clinically relevant inhibitor for Heptosyltransferase I (HepI) has been sought after for many years and while many have designed novel small-molecule inhibitors, these compounds lack the bioavailability and potency necessary for therapeutic use. Extensive characterization of the HepI protein has provided valuable insight into the dynamic motions necessary for catalysis that could be targeted for inhibition. With the help of molecular dynamic simulations, aminoglycoside antibiotics were shown to be putative inhibitors for HepI and in this study, they were experimentally determined to be the first in-class nanomolar inhibitors of HepI with the best inhibitor demonstrating a Ki of 600 +/- 90 nM. Detailed kinetic analyses were performed to determine the mechanism of inhibition while circular dichroism spectroscopy, intrinsic tryptophan fluorescence, docking, and MD simulations were used to corroborate kinetic experimental findings. Kinetic analysis methods include Lineweaver-Burk, Dixon, Cornish-Bowden and Mixed-Model of Inhibition which allowed for unambiguous assignment of inhibition mechanism for each inhibitor. In this study, we show that neomycin and kanamycin b are competitive inhibitors against the sugar acceptor substrate while tobramycin exhibits a mixed inhibitory effect and streptomycin is non-competitive. MD simulations also allowed us to suggest that the inhibitors bind tightly and inhibit catalytic dynamics due to a major desolvation penalty of the enzyme active site. While aminoglycosides have long been known as a class of potent antibiotics, they also have been scientifically shown to impact cell membrane stability, and we propose that inhibition of HepI contributes to this effect by disrupting lipopolysaccharide biosynthesis.

Foliar Nourishment with Different Zinc-Containing Forms Effectively Sustains Carrot Performance in Zinc-Deficient Soil

Among the essential micronutrients, zinc (Zn) affects vital functions in crop plants. The influences of foliar nourishing with certain Zn-containing forms on the growth, productivity, and physiology of carrot plants (cv. Fire wedge F1) and their nutritional contents when grown in Zn-deficient soil were examined in both 2019/2020 and 2020/2021 field trials. Two doses of zinc oxide nanoparticles (ZnO-NPs(1) = 20 and ZnO-NPs(2) = 40 mg L−1), zinc–EDTA (Zn–EDTA(1) = 1 and Zn–EDTA(2) = 2 g L−1), or bulk zinc oxide (ZnO-B(1) = 200 and ZnO-B(2) = 400 mg L−1) were applied three times. The data outputted indicated, in general, that ZnO-NPs(2) were the best treatment that conferred more acceptable plant growth (measured as shoot length and fresh and dry weights), physiology (measured as cell membrane stability index, SPAD readings, and nutrient uptake), and nutritional homeostasis (e.g., P, Ca, Fe, Mn, Zn, and Cu contents). All these positive attributes were reflected in the highest yield, which was measured as fresh weight, dry matter, length, diameter, volume, and total yield of carrot roots. However, there were some exceptions, including the highest membrane stability index in both seasons, the highest Cu uptake and Mn content in the first season, and root fresh weight in both seasons obtained with ZnO-NPs(1). Moreover, the maximum P uptake and root dry matter were obtained with ZnO-B(1) and the highest content of root P was obtained by ZnO-B(2). Based on the above data, foliar nourishing with ZnO-NPs(2) can be recommended for the sustainability of carrot cultivation in Zn-deficient soils.

Gamze Kaya GERMINATION, STOMATAL AND PHYSIOLOGICAL RESPONSE OF ROCKET (Eruca sativa L.) TO SALINITY

The response of rocket (Eruca sativa L.) to salinity stress was tested for several germination and physiological parameters during seedling development. Two rocket cultivars (Ilıca and Istanbul) and various salinity stresses of 0, 5, 10, 15 and 20 dS m–1 created by NaCl were used in the study. Germination percentage (GP), mean germination time (MGT), germination index (GI), germination stress tolerance index (GSTI), stomata morphology, chlorophyll content (SPAD value), leaf dry matter, relative water content (RWC), cellular injury (CI) and cell membrane stability (CMS) were evaluated. Results showed that high salinity stresses led to a decrease in GP, GI and GSTI index, while MGT increased. Salinity reduced stoma length and pore length. Under saline conditions, leaf dry matter, chlorophyll content and CMS increased, while RWC decreased. Also, CI was enhanced by salinities over 10 dS m–1. It was concluded that lower CMS, CI and RWC, and greater dry matter and chlorophyll were considered as salinity tolerance at the seedling stage of the rocket, and Istanbul was more tolerant to salinity than Ilıca.

Rhizobacteria Inoculation and Caffeic Acid Alleviated Drought Stress in Lentil Plants

Lentil (Lens culinaris Medik) is an important component of the human diet due to its high mineral and protein contents. Abiotic stresses, i.e., drought, decreases plant growth and yield. Drought causes the synthesis of reactive oxygen species, which decrease a plant’s starch contents and growth. However, ACC-deaminase (1-aminocyclopropane-1-carboxylate deaminase) producing rhizobacteria can alleviate drought stress by decreasing ethylene levels. On the other hand, caffeic acid (CA) can also positively affect cell expansion and turgor pressure maintenance under drought stress. Therefore, the current study was planned with an aim to assess the effect of CA (0, 20, 50 and 100 ppm) and ACC-deaminase rhizobacteria (Lysinibacillus fusiform, Bacillus amyloliquefaciens) on lentils under drought stress. The combined application of CA and ACC-deaminase containing rhizobacteria significantly improved plant height (55%), number of pods per plant (51%), 1000-grain weight (45%), nitrogen concentration (56%), phosphorus concentration (19%), potassium concentration (21%), chlorophyll (54%), relative water contents RWC (60%) and protein contents (55%). A significant decrease in electrolyte leakage (30%), proline contents (44%), and hydrogen peroxide contents (54%), along with an improvement in cell membrane stability (34% over control) validated the combined use of CA and rhizobacteria. In conclusion, co-application of CA (20 ppm) and ACC-deaminase producing rhizobacteria can significantly improve plant growth and yield for farmers under drought stress. More investigations are suggested at the field level to select the best rhizobacteria and CA level for lentils under drought.

Phylogenetic and expression dynamics of tomato ClpB/Hsp100 gene under heat stress

Heat shock proteins (Hsps) are stress-responsive molecular chaperones, which uphold proper protein folding in response to external and internal stresses. The Hsp100 gene family plays a substantial role in thermos-tolerance of plants. This study investigated evolutionary relationship and expression of ClpB/Hsp100 gene family in tomato under heat stress. Six SlHsp100 genes were identified using bioinformatics tools. In silico sub-cellular localization indicated that of these 6 ClpB/Hsp100 members, 4 are found in chloroplast, 1 in mitochondria and 1 in the cytoplasm. For evolutionary study, 36 SlHsp100 genes were included in the phylogenetic tree showing a hierarchical clustering shared by the members of the kingdoms Plantae, Archaea, Chromista, Fungi and Bacteria. A total 4 pairs of orthologous and 5 pairs of paralogous genes were identified. Functional divergence between different Hsp100 clusters showed considerable functional homology. Thermo-tolerance measured in terms of cell viability, cell membrane stability and pollen viability indicated that it was paralleled by thermal resistance of Hsps. Reverse transcriptase polymerase chain reaction was used to analyze gene expression in leaves of five-week-old tomato seedlings following exposure to heat stress (45°C) and control (25°C). Chloroplastic LeHSP110/ClpB gene was upregulated in all tomato genotypes after exposure to heat stress highlighting the crucial role of this gene family in acquired thermo-tolerance.

Réponse au déficit hydrique progressif chez la lentille : vers une différentiation morpho-physiologique entre des accessions sauvages (Lens orientalis), populations locales et lignées avancées (Lens culinaris Medik.)

La Lentille (Lens culinaris Medik.) contribue à la sécurité alimentaire et à la durabilité des systèmes agricoles. La tolérance à la sècheresse est un objectif majeur pour la création variétale. Cette étude visait la comparaison des réponses des populations locales, accessions sauvages Lens orientalis et des lignées avancées au stress hydrique progressif en pots sous serre. Les accessions sauvages ont démontré une grande tolérance au stress hydrique par rapport aux lignées avancées et populations locales. Elles avaient un ratio des racines/la matière sèche aérienne, contenu relatif en eau des feuilles, une dépression de la température du couvert et une stabilité de la membrane cellulaire plus élevés ainsi qu’une sévérité de flétrissement et un taux de perte d’eau des feuilles plus faible. Une différentiation génétique claire pour la tolérance à la sécheresse entre les trois groupes génétiques a été montrée. Différentes réponses morpho-physiologiques du matériel génétique ont été observées, correspondant à différents mécanismes de tolérance à la sécheresse. Les accessions sauvages, les lignées avancées et les nouvelles variétés améliorées INRA Maroc A3, A4, A5, A6 et A7 ainsi que la lentille de Zaer, une population locale bénéficiant d’un label de qualité connue dans le pays, ont été identifiées comme les plus tolérantes à la sécheresse parmi le matériel génétique étudié. Ces accessions pourraient être utilisées dans les programmes d’amélioration génétique dans la perspective de développer des variétés tolérantes à la sécheresse. Lentil (Lens culinaris, Medik.) is one of the world’s most important food legumes, contributing to food security and sustainable farming. Drought tolerance is a major objective of breeding programs. This work aimed at comparing genotypes with different genetic background (landraces, Lens orientalis wild accessions and elite advanced lines) under two watering regimes (well-watered; progressive water deficit). Drought tolerance was assessed based on morphological and physiological parameters: leaves’ relative water content and water losing rate, cell membrane stability, canopy temperature, root/shoot ratio, seedling vigor, wilting severity and harvest index. The evaluation was carried out in a greenhouse pot experiment using three replications. Wild accessions were more drought tolerant than advanced lines and landraces. They had higher root/shoot ratio, leaves’ relative water content, canopy temperature depression and cell membrane stability and lower wilting severity and leaves’ water losing rate. Discriminant factor analysis highlighted a clear genetic differentiation for drought tolerance between the three genetic groups. Different morpho-physiological responses of the studied genetic material have been observed corresponding to different drought tolerance mechanisms. Wild accessions, advanced lines and new improved INRA Morocco varieties A3, A4, A5, A6 and A7 as well as lentil of Zaer, a specific landrace with specific quality mark distinction known in the country, were identified as the most drought tolerant among the studied material. These accessions could be used in genetic improvement programs for developing drought tolerant varieties

Dystrophin modulates focal adhesion tension and YAP-mediated mechanotransduction

Dystrophin is an essential muscle protein that contributes to cell membrane stability by linking the actin cytoskeleton to the extracellular matrix. The absence or impaired function of dystrophin causes muscular dystrophy. Focal adhesions are mechanosensitive adhesion complexes that also connect the cytoskeleton to the extracellular matrix. However, the interplay between dystrophin and focal adhesion force transmission has not been investigated. Using a bioluminescent tension sensor, we measured focal adhesion tension in transgenic C2C12 myoblasts expressing wild type (WT) dystrophin, a non-pathogenic SNP (I232M), or two missense mutations associated with Duchenne (L54R), or Becker muscular dystrophy (L172H). We found that myoblasts expressing WT or nonpathogenic I232M dystrophin showed increased focal adhesion tension compared to non-transgenic myoblasts, while myoblasts expressing L54R or L172H dystrophin presented with decreased focal adhesion tension. Moreover, myoblasts expressing L54R or L172H dystrophin showed decreased YAP activation and exhibited slower and less directional migration compared to cells expressing WT or I232M dystrophin. Our results suggest that disease-causing missense mutations in dystrophin may disrupt a cellular tension sensing pathway in dystrophic skeletal muscle.

Effectiveness of zinc chloride mouthwashes on oral mucositis and weight of patients with cancer undergoing chemotherapy

Background Oral mucositis is one of the most emerging and debilitating complications of chemotherapy during the treatment period, which strongly affects the nutritional status and physical and mental condition of these patients. Zinc increased protein synthesis and improved cell membrane stability so passible effective in prevent and treat oral mucositis and promote oral health. Therefore, this study aimed to evaluate the effect of zinc chloride mouthwash on the prevention, incidence, and severity of oral mucositis in cancer patients undergoing chemotherapy. Methods The present study was a randomized control trial study. 96 patients with a cancer diagnosis selected from one oncology clinic in the west of Iran. Then they assigned randomly to the zinc chloride group and placebo group. The patients in each group should rinse their mouths every 8 h two times and each time 2 min with 7.5 ml from mouthwash. The severity of mucositis and weight loss examined blindly at the baseline and 3-week follow-up. Results The incidence and severity of oral mucositis between groups were significant higher at the end of the second (p < 0.002) and third (p < 0.001) week. The mucositis severity decreased well during the third weeks in the zinc chloride group. The difference in the weight loss was significant higher between the zinc chloride and the placebo group (p < 0.01). Conclusion Zinc chloride mouthwash was effective in preventing and reducing the severity of oral mucositis and improving weight in patients undergoing chemotherapy. Trial registration We can therefore recommend more studies examine the effects zinc chloride as preventive care at the beginning of chemotherapy to improve oral health and subsequently preventing weight loss in these patients.