Higher Osmotic Adjustment Research Articles

Maize genotypes with favourable dgat1–2 and fatb alleles possess stable high kernel oil and better fatty acid health and nutritive indices

Diverse uses of maize oil attracted various stakeholders, including food, feed, and bioenergy, highlighting the increased demand for sustainable production. Here, 48 diverse sub-tropical maize genotypes varying for dgat1–2 and fatb genes governing oil attributes, were evaluated in three diverse locations to assess trends of oil content, fatty acid (FA) profile, the effect of environment on oil attributes, the impact of different gene combinations and determine FA health and nutritional properties. The genotypes revealed wide variation in oil content (OC: 3.4–6.8 %) and FA compositional traits, namely palmitic (PA, 11.3–24.1 %), oleic (OA, 21.5–42.7 %), linoleic (LA, 36.6–61.7 %), and linolenic (ALA, 0.7–2.3 %) acids. Double-mutants with both favourable alleles (dd/ff) exhibited 51.6 % higher oil, 33.2 % higher OA, and 30.2 % reduced PA compared to wild-types (d+d+/f+f+) across locations. These double-mutants had lower saturated FA (12.2 %), and higher unsaturated FA (87.0 %), indicating reduced susceptibility to autooxidation, with lower atherogenicity (0.14), thrombogenicity (0.27) and peroxidisability (48.15), higher cholesterolemic index (7.16), optimum oxidability (5.27) and higher nutritive-value-index (3.35) compared to d+d+/f+f+, making them promising for significant health and nutritional benefits. Locally adapted stable novel double-mutants with high-oil and better FA properties identified here can expedite the maize breeding programs, meeting production demands and addressing long-standing challenges for breeders.

Molecular insights into the oleic acid accumulation in safflower

AbstractMost of the Indian safflower (Carthamus tinctorius L.) varieties produce oil rich in linoleic acid (LA, ~75%) and low in oleic acid (OA, ~15%). In the fatty acid biosynthetic pathway, the fatty acid desaturase 2 (FAD2) enzyme converts OA to LA. Safflower is reported to have 12–20 FAD2 genes. Gene expression analysis of four FAD2 genes during seed development in a high LA variety, PBNS‐12, revealed high expression of FAD2‐1 at 21 days after flowering (DAF), correlating with high LA accumulation. Fatty acid profiling of 448 Indian safflower germplasm accessions revealed four lines to have high (58%–77%) OA content, with NASF‐39 having the highest OA content. Interestingly, all four high OA lines showed the same mutation in the FAD2‐1 gene. The DNA sequence of FAD2‐1 from the four high OA lines showed a deletion of C at the +606 position, resulting in a premature stop codon at the +733 position and a truncated protein of 244 amino acids. Hence, despite the high expression levels of FAD2‐1 in NASF‐39 at 18–21 DAF, it exhibited high OA (77%). The dysfunctional nature of the truncated FAD2‐1 in NASF‐39 was evident in molecular docking studies with 1‐stearoyl‐2‐oleoyl phosphatidylcholine. We also sequenced FATB, a thioesterase responsible for releasing stearic acid from acyl carrier protein for further desaturation to oleic acid, where an A773G substitution was observed. This resulted in E258G substitution in NASF‐39 FATB compared to that of PBNS‐12. This probably made the acyl‐binding pocket of NASF‐39 FATB unstable, contributing to high OA accumulation. Thus, the outcomes of this study can help develop super and ultra‐high oleic safflower varieties through various genetics and genomics approaches.

Enhancing kernel oil and tailoring fatty acid composition by genomics-assisted selection for dgat1-2 and fatb genes in multi-nutrient-rich maize: new avenue for food, feed and bioenergy.

Enhancing maize kernel oil is vital for improving the bioavailability of fat-soluble vitamins. Here, we combined favourable alleles of dgat1-2 and fatb into parental lines of four multi-nutrient-rich maize hybrids (APTQH1, APTQH4, APTQH5 and APTQH7) using marker-assisted selection (MAS). Parental lines possessed favourable alleles of crtRB1, lcyE, vte4 and opaque2 genes. Gene-specific markers enabled successful foreground selection in BC1F1, BC2F1 and BC2F2, while background selection using genome-wide microsatellite markers (127-132) achieved 93% recurrent parent genome recovery. Resulting inbreds exhibited significantly higher oil (6.93%) and oleic acid (OA, 40.49%) and lower palmitic acid (PA, 14.23%) compared to original inbreds with elevated provitamin A (11.77 ppm), vitamin E (16.01 ppm), lysine (0.331%) and tryptophan (0.085%). Oil content significantly increased from 4.80% in original hybrids to 6.73% in reconstituted hybrids, making them high-oil maize hybrids. These hybrids displayed 35.70% increment in oil content and 51.56% increase in OA with 36.32% reduction in PA compared to original hybrids, while maintaining higher provitamin A (two-fold), vitamin E (nine-fold), lysine (two-fold) and tryptophan (two-fold) compared to normal hybrids. Lipid health indices showed improved atherogenicity, thrombogenicity, cholesterolaemic, oxidability, peroxidizability and nutritive values in MAS-derived genotypes over original versions. Besides, the MAS-derived inbreds and hybrids exhibited comparable grain yield and phenotypic characteristics to the original versions. The maize hybrids developed in the study possessed high-yielding ability with high kernel oil and OA, low PA, better fatty acid health and nutritional properties, higher multi-vitamins and balanced amino acids, which hold immense significance to address malnutrition and rising demand for oil sustainably in a fast-track manner.

Ultrasonic-assisted Co-precipitation synthesis of CoAl2O4 with different capping agents: Determination of electrical and optical features

In this study, cobalt aluminate nanoparticles were synthesized by a modified coprecipitation method using different capping agents and ultrasonic treatment. Optical, morphological and structural analyses of the samples were performed and the dielectric behaviour of the samples was investigated using the impedance spectroscopy technique in the frequency range of 10–107 Hz and at room temperature. It was determined that with the use of capping agent for NPs with 30–60 nm grain size, the optical forbidden energy gaps increased from 1.80 eV to 2.15 eV and the Co/Al ratio decreased from 0.534 to 0.362. It has been shown by Williamson Hall analysis that lattice shrinkage occurs with the use of the capping agent in the structural analysis of the materials. It has been determined that the type of capping agent is effective on the grain size, optical absorption and structural content of the final product, and especially lattice shrinkage is an effective mechanism in grain size reduction. The effect seen in the materials produced with the highest OA caused a 50 % decrease in grain size compared to the one without the use of capping agent. AC impedance spectroscopy showed that CoAl2O4 spinel structures have the inhomogeneous distribution of conductive grains with limited conductive grain boundaries and behave in accordance with Koops' model. It was determined that the use of dielectric properties in the high-frequency region improved with the use of capping agents.

Water stress and increased ploidy level enhance antioxidant enzymes, phytohormones, phytochemicals and polyphenol accumulation of tetraploid induced wallflower

Wallflower (Erysimum cheiri (L.) Crantz) is a profitable plant in the food, cosmetic, and pharmaceutical industries, as it produces valuable phenolic compounds. It is also an important flower in the floriculture industry cultivated mainly in the gardens and pots. Nonetheless, water scarcity as a worldwide phenomenon has deteriorated its growth and productivity. A main mechanism for drought tolerance is genome duplication and increased ploidy level, where more metabolites are produced. In this regard, diploid and tetraploid-induced plants of E. cheiri were subjected to well-watered (100% field capacity) and water deficit (50% field capacity) conditions for 30 days. Under water deficit conditions, the tetraploid wallflowers conserved their relative water content (RWC) at 85%, while the RWC of diploid plants was reduced to 68%. The chromosome-doubled plants showed advantages under water stress due to their higher osmotic adjustment by increased total soluble sugar and proline content, stronger antioxidant enzymes’ activity of SOD, CAT, APX, and POD, and enhanced non-enzymatic defense systems (i.e., total phenolic and flavonoid contents), compared with their control diploids. Also, stress hormones such as abscisic acid, salicylic acid, jasmonic acid, and auxins were increased in tetraploid plants under low water conditions, though cytokinin and gibberellin phytohormones were decreased as an adaptive strategy in the stress condition. Furthermore, chlorogenic acid and gallic acid were identified as the main phenolic compounds in 4x Erysimum leaves. The superiority of tetraploids over the diploid plants under water stress might be attributed to the extensive reprogramming of genes involved in hormonal signaling, reactive oxygen species detoxification, osmotic adjustment, and enhanced antioxidant defense system. The polyploidization technique combined with water scarcity, have proved fruitful for the production of excess secondary metabolites for various industrial uses.

EAS-CNN: automatic design of convolutional neural network for remote sensing images semantic segmentation

ABSTRACT Accurate and effective semantic segmentation methods for remote sensing are important for applications such as precision agriculture, urban planning, and disaster monitoring. Convolutional neural networks (CNN) have achieved remarkable performance in the field of remote sensing semantic segmentation. However, the design of CNNs is both time-consuming and necessitates a substantial amount of domain expertise and experience. To address the aforementioned issues, we propose a neural architecture search method called EAS-CNN. The method constructs a search space based on a U-shaped structure and utilizes a fixed-length encoding solution based on gene expression suppression to preserve potential useful information during the evolution process. Furthermore, an improved genetic strategy is proposed to enhance search efficiency and save computational resources. In this paper, we evaluate the proposed EAS-CNN method against state-of-the-art semantic segmentation methods and verify its effectiveness. Experimental results show that EAS-CNN achieves high OA values of 91.2% and 91.6% on the Vaihingen and Postman datasets, respectively. Furthermore, we conduct a thorough analysis of the experimental results and summarize effective design patterns for model architecture to enhance remote sensing semantic segmentation tasks.

Differential analysis of landscape patterns of land cover products in tropical marine climate zones – A case study in Malaysia

Abstract Land cover in tropical marine climate zones is important for global climate change. The existing analysis of land cover product consistency mainly focuses on a continental or national scale and rarely takes different geographical zones (such as tropical marine climate zones) as examples to carry out micro-interpretation from the perspective of ecology from the grid scale. In fact, some types of land cover under different zones have poor accuracy due to the standard of cognition and the complexity of the spatial pattern of ground objects. In addition, land cover and its change in tropical Marine climate zones will affect the greenhouse effect, energy balance, water transport, and so on, thus affecting climate change on a regional or even global scale. Therefore, this article presents an evaluation based on GLOBCOVER, CCI LC, and MCD12Q1 data using Malaysia as a case study, through area composition similarity, field sample point validation, and landscape indices. The results showed that (1) the area correlation coefficient between GLOBCOVER and CCI LC is the highest at 0.998. (2) The CCI LC had the highest OA and kappa coefficient of 59.01% and 0.4957, while the GLOBCOVER product had the lowest OA and kappa coefficient of 49.24% and 0.3614, respectively. (3) The consistency of the water landscape index is high between the CCI LC and GLOBCOVE data, the consistency of the artificial surfaces landscape index is high between the CCI LC and MCD12Q1 products, and the consistency of the grassland/shrubland landscape index is high between the GLOBCOVE and MCD12Q1 products. The results of microscopic landscape patterns show that the three product landscape patterns are generally more consistent in East Malaysia than in West Malaysia. The low accuracy of grassland, bareland, and shrubland is the key reason for the wide variation in landscape patterns between the three products.

Differential responses of contrasting low phosphorus tolerant cotton genotypes under low phosphorus and drought stress

BackgroundDrought is one of the main reasons for low phosphorus (P) solubility and availability.AimsThe use of low P tolerant cotton genotypes might be a possible option to grow in drought conditions.MethodsThis study investigates the tolerance to drought stress in contrasting low P-tolerant cotton genotypes (Jimian169; strong tolerant to low P and DES926; weak tolerant to low P). In hydroponic culture, the drought was artificially induced with 10% PEG in both cotton genotypes followed by low (0.01 mM KH2PO4) and normal (1 mM KH2PO4) P application.ResultsThe results showed that under low P, PEG-induced drought greatly inhibited growth, dry matter production, photosynthesis, P use efficiency, and led to oxidative stress from excessive malondialdehyde (MDA) and higher accumulation of reactive oxygen species (ROS), and these effects were more in DES926 than Jimian169. Moreover, Jimian169 alleviated oxidative damage by improving the antioxidant system, photosynthetic activities, and an increase in the levels of osmoprotectants like free amino acids, total soluble proteins, total soluble sugars, and proline.ConclusionsThe present study suggests that the low P-tolerant cotton genotype can tolerate drought conditions through high photosynthesis, antioxidant capacity, and osmotic adjustment.

Transcriptome and Metabolome Analysis Reveals Salt-Tolerance Pathways in the Leaves and Roots of ZM-4 (Malus zumi) in the Early Stages of Salt Stress.

The breeding of salt-tolerant rootstock relies heavily on the availability of salt-tolerant Malus germplasm resources. The first step in developing salt-tolerant resources is to learn their molecular and metabolic underpinnings. Hydroponic seedlings of both ZM-4 (salt-tolerant resource) and M9T337 (salt-sensitive rootstock) were treated with a solution of 75 mM salinity. ZM-4's fresh weight increased, then decreased, and then increased again after being treated with NaCl, whereas M9T337's fresh weight continued to decrease. The results of transcriptome and metabolome after 0 h (CK) and 24 h of NaCl treatment showed that the leaves of ZM-4 had a higher content of flavonoids (phloretinm, naringenin-7-O-glucoside, kaempferol-3-O-galactoside, epiafzelechin, etc.) and the genes (CHI, CYP, FLS, LAR, and ANR) related to the flavonoid synthesis pathway showed up-regulation, suggesting a high antioxidant capacity. In addition to the high polyphenol content (L-phenylalanine, 5-O-p-coumaroyl quinic acid) and the high related gene expression (4CLL9 and SAT), the roots of ZM-4 exhibited a high osmotic adjustment ability. Under normal growing conditions, the roots of ZM-4 contained a higher content of some amino acids (L-proline, tran-4-hydroxy-L-prolin, L-glutamine, etc.) and sugars (D-fructose 6-phosphate, D-glucose 6-phosphate, etc.), and the genes (GLT1, BAM7, INV1, etc.) related to these two pathways were highly expressed. Furthermore, some amino acids (S-(methyl) glutathione, N-methyl-trans-4-hydroxy-L-proline, etc.) and sugars (D-sucrose, maltotriose, etc.) increased and genes (ALD1, BCAT1, AMY1.1, etc.) related to the pathways showed up-regulation under salt stress. This research provided theoretical support for the application of breeding salt-tolerant rootstocks by elucidating the molecular and metabolic mechanisms of salt tolerance during the early stages of salt treatment for ZM-4.

The urban morphology classification under local climate zone scheme based on the improved method - A case study of Changsha, China

Generating local climate zone (LCZ) maps has been a new way for understanding urban morphology recently. So far, LCZ mapping has two major methods. WUDAPT workflow is widely used because of time-saving mapping process, while GIS stream is more complex and has obstacles such as lack of localized LCZ parameters, difficulty of parameter collection and unclear mapping specifications. Based on the original LCZ scheme, the study aims to fill the research gap by adopting GIS-based rules to identify urban morphology using multi-source dataset. Firstly, the study adjusts the LCZ types and LCZ parameters according to the current situation of Changsha. Secondly, a comprehensive set of LCZ parameters are calculated and evaluated, including Building Height (BH), Building Surface Fraction (BSF), Floor Area Ratio (FAR), Sky View Factor (SVF), Street Canyon Ratio (SCR), Impervious Surface Fraction (ISF), Pervious Surface Fraction (PSF), Tree Information (TH), Terrain Roughness (TR) and Albedo (AL). Thirdly, each 250 m × 250 m cell is classified according to the LCZ parameter threshold. The result indicates a higher OA (84.40%) of GIS stream comparing WUDAPT workflow. This study provides a clear depiction of improved GIS stream, which contributes to the development of LCZ mapping and also provides support for climate-sensitive urban development.

Impact of Power on Uneven Development: Evaluating Built-Up Area Changes in Chengdu Based on NPP-VIIRS Images (2015–2019)

In the context of uneven development studies of China, urban built-up area changes are the index of the impact of power, as the local government is the only party that is able to acquire agricultural land and convert it to construction urban land. Existing studies generally use statistical data to describe the built-up area changes and struggle to meet the requirement of an updated and inexpensive monitoring of uneven development, especially for western cities with tight budgets. Open access NPP-VIIRS (Suomi National Polar-orbiting Partnership Visible Infrared Imaging Radiometer Suite), NDVI (Normalized Difference Vegetation Index), and nighttime LST (Land Surface Temperature) data ranging from 2015 to 2019 were analyzed with a stratified SVM (Support Vector Machine) method in this study to track urban built-up area changes in Chengdu, one of the biggest cities in Western China. The SDE (Standard Deviation Ellipse) and Moran’s I were then applied to evaluate the spatial variations of the built-up area changes. It was revealed that the spatial evolution of built-up area change in Chengdu over the period 2015–2019 demonstrated a “northwest-southeast” spatial expansion pattern, and the change distance in the center of gravity in 2018 and 2019 was greater than that from 2015 to 2017, which reflected the faster uneven development in 2018 and 2019 in Chengdu. The results were verified with finer resolution Landsat-8 OLI images; the high OA (all larger than 92%) and KAPPA (all larger than 0.6) values showed the accuracy of the method. The methodology proposed in this study offers a practical way for cities with tight budgets to monitor uneven development, and this study suggests a further adaption using higher-resolution remote sensing images and field experiments.

A Novel Classification Framework for Hyperspectral Image Data by Improved Multilayer Perceptron Combined with Residual Network

Convolutional neural networks (CNNs) have attracted extensive attention in the field of modern remote sensing image processing and show outstanding performance in hyperspectral image (HSI) classification. Nevertheless, some hyperspectral images have fixed position priors and parameter sharing between different positions, so the common convolution layer may ignore some important fine and useful information and cannot guarantee to effectively capture the optimal image features. This paper proposes an improved multilayer perceptron (IMLP) and IMLP combined with ResNet (IMLP-ResNet) two models for HSI classification. Combined with the characteristics of hyperspectral data, we design IMLP based on three improvements. Specifically, a depthwise over-parameterized convolutional layer is introduced to increase learnable parameters of the model in IMLP, which speeds up the convergence of the model without increasing the computational complexity. Secondly, a Focal Loss function is used to suppress the useless ones in the classification task and enhance the critical spectral–spatial features, which allow the IMLP network to learn more useful hyperspectral image information. Furthermore, to enhance the convergence speed of the network, cosine annealing is introduced to further improve the training performance of IMLP. Furthermore, the IMLP module is combined with a residual network (IMLP-ResNet) to construct a symmetric structure, which extracts more advanced semantic information from hyperspectral images. The proposed IMLP and IMLP-ResNet are tested on the two public HSI datasets (i.e., Indian Pines and Pavia University) and a real hyperspectral dataset (Xuzhou). Experimental results demonstrate the superiority of the proposed IMLP-ResNet method over several state-of-the-art methods with the highest OA, which outperforms CNN by 8.19%, 6.28%, 5.59% and outperforms ResNet by 3.52%, 3.54%, 2.67% on Indian Pines, Pavia University and Xuzhou datasets, respectively, and demonstrates that the well-designed MLPs can also obtain remarkable classification performance of HSI.

Distinct contributions of drought avoidance and drought tolerance to yield improvement in dryland wheat cropping

AbstractCrop avoidance and tolerance strategies are critical adaptive mechanisms of drought stress and play different roles in grain yield. However, little is known about the contribution of these two mechanisms to grain yield in old and modern wheat genotypes. Here, pot and field experiments were carried out to characterize and compare the mechanisms of drought avoidance and drought tolerance, and determine their differential contributions to the yield in six wheat genotypes. The pot experiment results demonstrated that the old genotypes acquired a better avoidance ability to adapt to drought stress. These avoidance abilities include larger root systems, lower leaf areas, low stomatal conductance, pale green leaf colour, higher degrees of leaf rolling and leaf waxiness. The modern genotypes displayed stronger drought tolerance advantages, such as high osmotic adjustment and antioxidant enzyme activity, and a smaller root system. Our field experiment further showed that under severe water‐deficit conditions, the old genotypes with stronger drought avoidance traits had higher yields and water use efficiency (WUEg), whereas the modern genotypes with strong drought tolerance characteristics produced higher yields and had higher WUEg under mild and intermediate water deficits. The results indicate that the relative contribution of drought tolerance and drought avoidance to grain yield depends to a large extent on the degree of drought stress and genotypes. Understanding the differential plant response depending on genotype and drought stress may help plant breeders develop drought‐resistant varieties suitable for drought‐prone environments under anticipated climate change scenarios.

Aberrant Fluid Shear Stress Contributes to Articular Cartilage Pathogenesis via Epigenetic Regulation of ZBTB20 by H3K4me3.

PurposeOsteoarthritis (OA) is a common disease for human beings, characterized by severe inflammation, cartilage degradation, and subchondral bone destruction. However, current therapies are limited to relieving pain or joint replacement and no effective treatment methods have been discovered to improve degenerative changes. Currently, a variety of evidences have indicated that aberrant mechanical stimuli is closely associated with articular joint pathogenesis, while the detailed underlying mechanism remains unelucidated. In the present study, we determined to investigate the impact of excessive high fluid shear stress (FSS) on primary chondrocytes and the underlying epigenetic mechanisms.Materials and MethodsPhalloidin staining and EdU staining were used to evaluate cell morphology and viability. The mRNA level and protein level of genes were determined by qPCR, Western blot assay, and immunofluorescence staining. Mechanistic investigation was performed through RNA-sequencing and CUT&Tag sequencing. In vivo, we adopted unilateral anterior crossbites (UAC) mice model to investigate the expression of H3K4me3 and ZBTB20 in aberrant force-related cartilage pathogenesis.ResultsThe results demonstrated that FSS greatly disrupts cell morphology and significantly decreased chondrocyte viability. Aberrant FSS induces remarkable inflammatory mediators production, leading to cartilage degeneration and degradation. In depth mechanistic study showed that FSS results in more than 10-fold upregulation of H3K4me3, and the modulatory effect of H3K4me3 on cartilage was obtained by directly targeting ZBTB20. Furthermore, Wnt signaling was strongly activated in high FSS-induced OA pathogenesis, and the negative impact of ZBTB20 on chondrocytes was also achieved through activating Wnt signaling pathway. Moreover, pharmacological inhibition of H3K4me3 activation by MM-102 or treatment with Wnt pathway inhibitor LF3 could effectively alleviate the destructive effect of FSS on chondrocytes. In vivo UAC mice model validated the dysregulation of H3K4me3 and ZBTB20 in aberrant force-induced cartilage pathogenesis.ConclusionThrough the combination of in vitro FSS model and in vivo UAC model, KMT2B-H3K4me3-ZBTB20 axis was first identified in aberrant FSS-induced cartilage pathogenesis, which may provide evidences for epigenetic-based therapy in the future.

Use of transcriptomic profiling to identify candidate genes involved in Polyporus umbellatus sclerotial formation affected by oxalic acid

Polyporus umbellatus is a precious medicinal fungus. Oxalic acid was observed to affect sclerotial formation and sclerotia possessed more medicinal compounds than mycelia. In this study, the transcriptome of P. umbellatus was analysed after the fungus was exposed to various concentrations of oxalic acid. The differentially expressed genes (DEGs) encoding a series of oxidases were upregulated, and reductases were downregulated, in the low-oxalic-acid (Low OA) group compared to the control (No OA) group, while the opposite phenomenon was observed in the high-oxalic-acid (High OA) group. The detection of reactive oxygen species (ROS) in P. umbellatus mycelia was performed visually, and Ca2+ and H2O2 fluxes were measured using non-invasive micro-test technology (NMT). The sclerotial biomass in the Low OA group increased by 66%, however, no sclerotia formed in the High OA group. The ROS fluorescence intensity increased significantly in the Low OA group but decreased considerably in the High OA group. Ca2+ and H2O2 influx significantly increased in the Low OA group, while H2O2 exhibited efflux in the High OA group. A higher level of oxidative stress formed in the Low OA group. Different concentrations of oxalic acid were determined to affect P. umbellatus sclerotial formation in different ways.

Resistome characterization of Flavobacterium columnare isolated from freshwater cultured Asian sea bass (Lates calcarifer) revealed diversity of quinolone resistance associated genes

Flavobacterium columnare is a Gram-negative bacterium which causes columnaris disease in freshwater fish species worldwide. Antibiotics, especially quinolone, is a primary therapeutic option to mitigate the economic loss caused by this disease. Phenotypic characterization and susceptibility testing were performed to identify quinolone resistance (QR)-associated genes in F. columnare isolated from freshwater cultured Asian sea bass. A total of 15 F. columnare isolates were collected from moribund fish that exhibited columnaris-like clinical signs and lesions including gill necrosis, saddleback lesion, and fin erosion. Phylogenetic analysis based on 16S rRNA and dnaK revealed that these isolates belonged to genetic group (GG) 2 and 4. Disk diffusion test results indicated that the 15 isolates were susceptible to all tested antibiotics except quinolones. Five and six isolates were resistant to oxolinic (OA) (33.33%) and nalidixic acid (NA) (40%) respectively. Broth microdilution indicated that highest OA, NA and enrofloxacin (ENR) minimum inhibitory concentration (MIC) values were 16, 64 and 1 μg/mL respectively. The MIC level to quinolone of GG 2 was higher for the GG 4 counterparts. Sequence analysis revealed a serine:phenylalanine amino acid substitution at position 83 (S83F) and a glutamine:histidine amino acid substitution at position 458 (Q458H) of quinolone resistance-determining regions (QRDRs) of gyrA and gyrB respectively. The Q458H in gyrB was identified as a novel non-synonymous mutation of the Flavobacteriaceae family. A genome-scale resistome analysis revealed that connections between GG and QR level potentially correlated with the presence or absence of chromosomal antimicrobial resistance genes and accumulated mutations in QRDRs. This study provide a guidance for choosing antibiotics for treatment columnaris disease and point out the important quinolone resistance mechanisms in F. columnare.

Abstract P471: Ipsilateral Asymmetrical Internal Cerebral Vein on Multiphasic Computed Tomography for Acute Anterior Circulation Ischemic Stroke Thrombectomy is an Independent Predictor of Poor Functional Outcome

Background: National Institute of health stroke scale(NIHSS) and collateral circulation are well-established predictors for functional outcomes of endovascular thrombectomy (EVT) patients in acute ischemic stroke (AIS), nonetheless additional prognostic markers can improve the prediction of stroke outcomes. The inflow and drainage into the internal cerebral veins (ICV) can be seen consistently on multiphasic computed tomography angiography (mCTA). Thus, we hypothesize that asymmetry of ICV in the mCTA in large vessel occlusion AIS can be used as an adjunctive predictor of functional outcomes and complications. Method: We enrolled 185 consecutive anterior circulation AIS patients who underwent EVT that presented to our hospital between 2017 and 2019. The collateral circulation was defined by the university of Calgary mCTA collateral flow assessment in stroke. The ICV on the ipsilateral occlusion side was compared with the contralateral side according to a binary scale: 1 (less than contralateral or absent) or 2(equal or greater than contralateral). The primary outcome was modified Rankin scale at 3 months (mRS), and secondary outcomes included symptomatic intracranial hemorrhage and mortality. Result: Among 185 patients, 53% were men, the median age 70 years (range 29-91) and the median NIHSS score on arrival (NIHSS OA) was 19 (range 4-34). 82 patients (44.3%) had good functional outcomes at 3 months. Ipsilateral asymmetry in all three stages of mCTA were statistically significantly associated with good functional outcomes. The 1 st delay phase of mCTA showed the strongest association. On multivariate analysis, high NIHSS OA (OR 1.09, 95% CI 1.02-1.15, P = 0.007), good mCTA collateral score (OR 0.30, 95% CI .16- .53, P < .001), ipsilateral asymmetrical ICV on the 1 st delay phase of mCTA (OR 2.64, 95% CI 1.17-5.96, P = 0.01) were independent predictors of poor functional outcome. Ipsilateral asymmetry was not associated with mortality or symptomatic intracranial hemorrhage on multivariate analysis. Conclusion: Ipsilateral assymetrical ICV is a novel radiological marker associated with functional outcomes after thrombectomy even after correction for the collateral circulation. Further studies should be done to validate this finding in different datasets.

Transgenic chickpea (Cicer arietinum L.) harbouring AtDREB1a are physiologically better adapted to water deficit

BackgroundChickpea (Cicer arietinum L.) is the second most widely grown pulse and drought (limiting water) is one of the major constraints leading to about 40–50% yield losses annually. Dehydration responsive element binding proteins (DREBs) are important plant transcription factors that regulate the expression of many stress-inducible genes and play a critical role in improving the abiotic stress tolerance. Transgenic chickpea lines harbouring transcription factor, Dehydration Responsive Element-Binding protein 1A from Arabidopsis thaliana (AtDREB1a gene) driven by stress inducible promoter rd29a were developed, with the intent of enhancing drought tolerance in chickpea. Performance of the progenies of one transgenic event and control were assessed based on key physiological traits imparting drought tolerance such as plant water relation characteristics, chlorophyll retention, photosynthesis, membrane stability and water use efficiency under water stressed conditions.ResultsFour transgenic chickpea lines harbouring stress inducible AtDREB1a were generated with transformation efficiency of 0.1%. The integration, transmission and regulated expression were confirmed by Polymerase Chain Reaction (PCR), Southern Blot hybridization and Reverse Transcriptase polymerase chain reaction (RT-PCR), respectively. Transgenic chickpea lines exhibited higher relative water content, longer chlorophyll retention capacity and higher osmotic adjustment under severe drought stress (stress level 4), as compared to control. The enhanced drought tolerance in transgenic chickpea lines were also manifested by undeterred photosynthesis involving enhanced quantum yield of PSII, electron transport rate at saturated irradiance levels and maintaining higher relative water content in leaves under relatively severe soil water deficit. Further, lower values of carbon isotope discrimination in some transgenic chickpea lines indicated higher water use efficiency. Transgenic chickpea lines exhibiting better OA resulted in higher seed yield, with progressive increase in water stress, as compared to control.ConclusionsBased on precise phenotyping, involving non-invasive chlorophyll fluorescence imaging, carbon isotope discrimination, osmotic adjustment, higher chlorophyll retention and membrane stability index, it can be concluded that AtDREB1a transgenic chickpea lines were better adapted to water deficit by modifying important physiological traits. The selected transgenic chickpea event would be a valuable resource that can be used in pre-breeding or directly in varietal development programs for enhanced drought tolerance under parched conditions.

Water Relations of Two Adjacently Growing Tree Species Shorea Robusta Gaertn-and Pinus Roxburbhii Sarg-in the Lower Himalayan Region

Water potential (predawn and mid day), water potential components (osmotic potential at full and zero turgor, relative water content), soil water potential and leaf conductance were measured for two adjacently growing tree species Shorea robusta Gaertn and Pinus roxburghii Sarg. at an elevation of 1370m. The stands were open and the density of S. robusta was 212 trees/ha and of P. roxburghii was 141trees/ha. Presence of high number of saplings indicates both the species were regenerating well in the site despite human disturbance. S. robusta maintained relatively high predawn water potential even in summers (above -0.50MPa) and P. roxburghii showed low predawn water potential in early summer and summer season (above-1.4 MPa). P. roxburghii maintained a relatively small daily change in water potential during early summer and summer season (0.33MPa and 0.27MPa) indicating greater ability of the species to close its stomata as drought intensifies. The values of osmotic potential at full and zero turgor remained more or less constant for S. robusta from monsoon to winter and then declined during early summer. P. roxburghii showed a gradual decline in osmotic potential values from monsoon to winter season. Chir-pine has the ability of invade and grow on sites that are water stressed which can be related to its capacity to show high osmotic adjustment.. The most negative values of soil water potential were in early summer in both years. The morning and afternoon conductance was lowest during early summer and highest in autumn season.

Wheat breeding highlights drought tolerance while ignores the advantages of drought avoidance: A meta-analysis

Crop tolerance and avoidance are critical adaptation mechanisms to cope with drought stress but they contribute differently to grain yield formation. Little is known about the different roles of these two mechanisms in long-term crop breeding. A meta-analysis was conducted to determine the different effects of drought tolerance and avoidance mechanisms on the drought adaptation of wheat crops. The meta-analysis summarized the results of 283 published papers in international journals, and illustrated that primitive wheat genotypes, including wild, cultivated diploids, tetraploids and old hexaploids, preferentially showed a drought avoidance strategy, as evidenced by large root biomass, small leaf area, and reduced stomatal conductance under water deficits. Modern hexaploid genotypes showed stronger drought tolerance advantages, such as high leaf water potential and osmotic adjustment, with a small root system. The meta-analysis indicated that the breeding process of dryland wheat has been continuously enhancing drought tolerance while weakening drought avoidance. Under severe water deficits, old hexaploid wheat genotypes with drought avoidance characteristics showed lower reduction of aboveground biomass and yield than modern genotypes with stronger drought tolerance features, while under mild and moderate water deficits genotypes with stronger drought tolerance features had higher yields and aboveground biomass. The meta-analysis provide information for making decisions on the direction of modern crop breeding and the implementing of managing practices to cope with drought stress, which frequency and severity is increasing with the advent of climate change.