Yearly Archives: 2023

Nifuroxazide repurposing for protection from diabetes‐induced retinal injury in rats: Implication of oxidative stress and JAK/STAT3 axis

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Nifuroxazide repurposing for protection from diabetes-induced retinal injury in rats: Implication of oxidative stress and JAK/STAT3 axis

Nifuroxazide (Nifu), the potent STAT3 inhibitor successfully protected the diabetic rats against diabetic retinopathy as it ameliorated the retinal structure deterioration. This effect could be attributed to modulating JAK/STAT3 axis and oxidative stress.


Abstract

The prevalence of diabetes mellitus (DM) is alarmingly increasing worldwide. Diabetic retinopathy (DR) is a prevailing DM microvascular complication, representing the major cause of blindness in working-age population. Inflammation is a crucial player in DR pathogenesis. JAK/STAT3 axis is a pleotropic cascade that modulates diverse inflammatory events. Nifuroxazide (Nifu) is a commonly used oral antibiotic with reported JAK/STAT3 inhibition activity. The present study investigated the potential protective effect of Nifu against diabetes-induced retinal injury. Effect of Nifu on oxidative stress, JAK/STAT3 axis and downstream inflammatory mediators has been also studied. Diabetes was induced in Sprague Dawley rats by single intraperitoneal injection of streptozotocin (50 mg/kg). Animals were assigned into four groups: normal, Nifu control, DM, and DM + Nifu. Nifu was orally administrated at 25 mg/kg/day for 8 weeks. The effects of Nifu on oxidative stress, JAK/STAT3 axis proteins, inflammatory factors, tight junction proteins, histological, and ultrastructural alterations were evaluated using spectrophotometry, gene and protein analyses, and histological studies. Nifu administration to diabetic rats attenuated histopathological and signs of retinal injury. Additionally, Nifu attenuated retinal oxidative stress, inhibited JAK and STAT3 phosphorylation, augmented the expression of STAT3 signaling inhibitor SOCS3, dampened the expression of transcription factor of inflammation NF-κB, and inflammatory cytokine TNF-α. Collectively, the current study indicated that Nifu alleviated DR progression in diabetic rats, suggesting beneficial retino-protective effect. This can be attributed to blocking JAK/STAT3 axis in retinal tissues with subsequent amelioration of oxidative stress and inflammation.

Strikingly convergent genome alterations in two independently evolved holoparasites

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Nature Plants, Published online: 21 September 2023; doi:10.1038/s41477-023-01518-6

Two independently evolved lineages of holoparasites — Balanophora (Santalales) and Sapria (Malpighiales) — display massively convergent characteristics of genome modifications, including gene loss in major pathways, reduction of multigene families and generally relaxed selection pressure. These findings provide valuable new insights into the fascinating biology of parasitic plants.

The Historic Square Foot Dataset – Outstanding small‐scale richness in Swiss grasslands around the year 1900

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The Historic Square Foot Dataset – Outstanding small-scale richness in Swiss grasslands around the year 1900

The Historic Square Foot Dataset comprises several hundred vegetation plots conducted between 1884 and 1931 in grassland habitats all over Switzerland. These data are unique in providing insights in how grasslands in Central Europe were composed, making them an important source of information for vegetation science and global-change studies. The digitised and georeferenced data are made accessible through this publication.


Abstract

Grasslands host a significant share of Europe's species diversity but are among the most threatened vegetation types of the continent. Resurvey studies can help to understand patterns and drivers of changes in grassland diversity and species composition. However, most resurveys are based on local or regional data, and hardly reach back more than eight decades. Here, we publish and describe the Historic Square Foot Dataset, comprising 580 0.09-m2 and 43 1-m2 vegetation plots carefully sampled between 1884 and 1931, covering a wide range of grassland types across Switzerland. We provide the plots as an open-access data set with coordinates, relocation accuracy and fractional aboveground biomass per vascular plant species. We assigned EUNIS habitat types to most plots. Mean vascular plant species richness in 0.09 m2 was 19.7, with a maximum of 47. This is considerably more than the present-day world record of 43 species for this plot size. Historically, species richness did not vary with elevation, differing from the unimodal relationship found today. The data set provides unique insight into how grasslands in Central Europe looked more than 100 years ago, thus offering manifold options for studies on the development of grassland biodiversity and productivity.

Combinatory ability and heterosis for quantitative traits related to productivity and the pungency in F1 hybrids of habanero pepper (Capsicum chinense Jacq.)

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Abstract

The objective of this work was to obtain high-yielding F1 hybrids of the habanero pepper, using 10 outstanding parents in a line-tester genetic design. General combinatorial ability and specific combinatorial ability were evaluated in the parents' and the hybrids F1 obtained, respectively. Heterosis was determined in the 18 hybrids obtained. The technique of HPLC was used to evaluate the capsaicin content in the fruit of 10 parents and 18 hybrids of habanero pepper. The DNA profiles were analysed as part of the characterization of the germplasm of the species conserved at the CICY. Furthermore, the molecular variation of the genotypes under investigation was assessed using eight SSR and nine ISSR markers. The results showed the presence of substantial morphoagronomic and molecular variability among the habanero pepper genotypes evaluated. Genetic similarities of 83%–93% between parents and 76%–94% between hybrids were found. The most productive hybrids were H8, H10 and H19 with 3.13 to 4.29 kg/plant, respectively, these came from crosses where RNJ-04 (P26) as the male parent and the hybrid H60 (4.92 kg/plant) that comes from the male parent RES-08 (P30). Likewise, the H7 hybrid had the highest capsaicin content (128.41 mg/g dry weight, 960,687.00 SHU). Hybrids H43 with 114.39 mg/g DW and 90,444.30 SHU, and H51 with 11.61 mg/g DW and 934,745.07 SHU respectively, also stood out.

Genomic prediction with machine learning in sugarcane, a complex highly polyploid clonally propagated crop with substantial non‐additive variation for key traits

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Abstract

Sugarcane has a complex, highly polyploid genome with multi-species ancestry. Additive models for genomic prediction of clonal performance might not capture interactions between genes and alleles from different ploidies and ancestral species. As such, genomic prediction in sugarcane presents an interesting case for machine learning (ML) methods, which are purportedly able to deal with high levels of complexity in prediction. Here, we investigated deep learning (DL) neural networks, including multilayer networks (MLP) and convolution neural networks (CNN), and an ensemble machine learning approach, random forest (RF), for genomic prediction in sugarcane. The data set used was 2912 sugarcane clones, scored for 26,086 genome wide single nucleotide polymorphism markers, with final assessment trial data for total cane harvested (TCH), commercial cane sugar (CCS), and fiber content (Fiber). The clones in the latest trial (2017) were used as a validation set. We compared prediction accuracy of these methods to genomic best linear unbiased prediction (GBLUP) extended to include dominance and epistatic effects. The prediction accuracies from GBLUP models were up to 0.37 for TCH, 0.43 for CCS, and 0.48 for Fiber, while the optimized ML models had prediction accuracies of 0.35 for TCH, 0.38 for CCS, and 0.48 for Fiber. Both RF and DL neural network models have comparable predictive ability with the additive GBLUP model but are less accurate than the extended GBLUP model.

Potential breeding target genes for enhancing agronomic drought resistance: A yield‐survival balance perspective

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Abstract

Amidst global climate warming, the urgency to enhance crop drought resistance has reached unprecedented levels. However, the achievement of superior drought-resistant crop varieties, despite substantial research investments, remains constrained. This limited success in transitioning from the laboratory to the field can be partly attributed to the disparity between evaluating biological and agronomic drought resistance (ADR). ADR places emphasis on minimizing yield losses during drought conditions and maintaining robust performance under normal circumstances. Here, we present a comprehensive overview of ADR genes reported during the past decades, categorized based on their yield performance under both drought and standard growth conditions. We highlight 23 genes from grain and legume crops, providing insight into their working mechanisms. Particularly, we delve into their efficacy in improving yields predominantly through transgenic approaches in field conditions. Furthermore, we briefly touch upon the adoption of emerging phenomics technologies, which can streamline the discovery and application of ADR genes. This review is poised to serve the breeding community, aiding in the selection of appropriate target genes to augment crop drought resistance.

Plant photosynthetic responses under drought stress: Effects and management

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Abstract

Balanced photosynthesis is essential for improved plant survival and agricultural benefits in terms of biomass and yield. Photosynthesis is the hub of energy metabolism in plants; however, drought stress (DS) strongly perturbs photosynthetic efficiency due to biochemical and diffusive limitations that reduce key photosynthetic components and close stomata. This review describes photosynthetic responses, chloroplast retrograde signalling, and genetic imprints that curtail DS damage to photosynthetic machinery. While stomatal closure, disrupted photosynthetic systems, over-reduced electron transport rates (ETR), partial hindrance of the Calvin cycle, and reduced pigment contents strongly affect the repertoire of photosynthetic processes under DS, chloroplast retrograde signalling also has a plausible role in preserving photosynthetic capacity. Progress in agronomic, genetic engineering approaches and isoprene regulation would help to rescue photosynthetic apparatus under DS.

Does the plant growth regulator paclobutrazol enhance root growth of maize exposed to drought stress during flowering?

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Abstract

Due to climate change, crop production will increasingly be affected by water limitation, causing remarkable decreases in grain yields of cereals. Plant growth regulators such as paclobutrazol (PAC) have been shown to protect plants from detrimental impacts of drought stress, and improvement of root growth and antioxidant activity were identified as main reasons for their positive effect. A container experiment was conducted with two maize (Zea mays L.) cultivars, Galactus and Fabregas, to investigate how PAC application affects root growth and grain yield under stress conditions. At growth stage V8, the plants were treated once with PAC (0, 2, or 3 mg PAC per plant), and concomitantly reduction in soil water content commenced until 30–35% of the maximum water-holding capacity (WHC) was achieved. The plants were exposed to this drought condition for three weeks during flowering as the critical period for kernel setting. Both factors, PAC application and drought stress, caused decreases in plant height, whereas total leaf area was unchanged and transpiration rate was significantly reduced by water limitation only. Flowering was almost unaffected by PAC treatment; yet, drought stress significantly delayed start of silking. The straw yield was decreased due to PAC and drought stress, and an improvement of the harvest index was obtained for drought-stressed Galactus plants with PAC application. Grain yield was unaffected by PAC application, whereas drought stress caused significant decreases by 15% on average of both cultivars. The kernel number of drought-stressed Galactus plants was increased after PAC treatment, but concurrently smaller kernels were produced. Water limitation generally decreased kernel number. Drought-stressed Fabregas plants consumed less water after PAC treatment, resulting in significant improvements of water-use efficiency (WUEgrain) during silking and thus most likely alleviating stress intensity. For both cultivars, PAC treatment and water limitation showed almost no significant impact on root dry matter, root length density, and root surface area, either determined for different soil layers down to 80 cm or on a per-plant basis. It is concluded that grain yield performance of maize plants, exposed to water limitation during flowering, was not source-limited but sink-limited. Consequently, even if PAC can cause improvement of antioxidant activity and photosynthesis, due to sufficient availability of assimilates in the maize kernels a positive effect on grain yield is improbable. Considering source–sink relationships during flowering and kernel set, enhanced root growth due to PAC treatment did apparently not occur.

Saline stress affects the growth of Saccharum complex genotypes

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Abstract

Soil salinity affects plant growth, compromising sugarcane cultivation in regions with great production potential. Saccharum complex genotypes that respond positively to growth under saline environment can be used in the diversification of sugarcane cultivars to obtain greater economic returns. The objective of this study was to evaluate growth-related traits of Saccharum genotypes grown under the presence and absence of salinity. The experiment was carried out in a 32 × 2 factorial scheme in a randomized block design with three replicates. The first factor consisted of 32 genotypes of the Saccharum complex and the second factor consisted of the presence and absence of salinity. The salinity provided higher mean values than the environment without salinity for plant height in the genotypes G9, G11, G13, G22 and G28, leaf number for G9 and G24, leaf area index for G9 and stem diameter for G1, G11 and G24. Among the genotypes tested, G1, G9, G11, G13, G22, G24 and G28 were the most promising genotypes and could be used for breeding new sugarcane cultivars of enhanced salinity tolerance.