Artificial Rainfall on Grain Quality and Baking Characteristics of Winter Wheat Cultivars in Korea.

Wheat (Triticum aestivum L.) stands as a significant cereal crop globally, including in Korea, where its consumption reached 35.7 kg per capita in 2023. In the southern regions of Korea, wheat cultivation follows paddy rice, with harvesting typically occurring during the rainy season in mid-June. This timing, coupled with the high humidity and unpredictable rainfall, often leads to pre-harvest sprouting and subsequent deterioration in flour quality. To assess the impact of rain on flour quality, an artificial rain treatment was administered 45 days after heading in an open field greenhouse, followed by flour quality analysis. The color measurement revealed an increase in the L* parameter, indicative of enhanced kernel vitreousness, attributed to endosperm starch degradation via alpha-amylase activation induced by water absorption. Moreover, significant changes were observed in ash content and the gluten index within the wetted group, resulting in decreased dough strength and stability, ultimately leading to a reduction in loaf volume. Consequently, it is recommended that wheat be harvested 4-7 days after reaching the physiological maturity stage to avoid the rainy season and ensure the production of high-quality wheat.

Synergizing breeding strategies via combining speed breeding, phenotypic selection, and marker-assisted backcrossing for the introgression of Glu-B1i in wheat.

Wheat is a major food crop that plays a crucial role in the human diet. Various breeding technologies have been developed and refined to meet the increasing global wheat demand. Several studies have suggested breeding strategies that combine generation acceleration systems and molecular breeding methods to maximize breeding efficiency. However, real-world examples demonstrating the effective utilization of these strategies in breeding programs are lacking. In this study, we designed and demonstrated a synergized breeding strategy (SBS) that combines rapid and efficient breeding techniques, including speed breeding, speed vernalization, phenotypic selection, backcrossing, and marker-assisted selection. These breeding techniques were tailored to the specific characteristics of the breeding materials and objectives. Using the SBS approach, from artificial crossing to the initial observed yield trial under field conditions only took 3.5 years, resulting in a 53% reduction in the time required to develop a BC2 near-isogenic line (NIL) and achieving a higher recurrent genome recovery of 91.5% compared to traditional field conditions. We developed a new wheat NIL derived from cv. Jokyoung, a leading cultivar in Korea. Milyang56 exhibited improved protein content, sodium dodecyl sulfate-sedimentation value, and loaf volume compared to Jokyoung, which were attributed to introgression of the Glu-B1i allele from the donor parent, cv. Garnet. SBS represents a flexible breeding model that can be applied by breeders for developing breeding materials and mapping populations, as well as analyzing the environmental effects of specific genes or loci and for trait stacking.

Exposure to hull cleaning wastewater induces mortality through oxidative stress and cholinergic disturbance in the marine polychaete Perinereis aibuhitensis.

While wastewater and paint particles discharged from the in-water cleaning process of ship hulls are consistently released into benthic ecosystems, their hazardous effects on non-target animals remain largely unclear. In this study, we provide evidence on acute harmful effects of hull cleaning wastewater in marine polychaete Perinereis aibuhitensis by analyzing physiological and biochemical parameters such as survival, burrowing activity, and oxidative status. Raw wastewater samples were collected during ship hull cleaning processes in the field. Two wastewater samples for the exposure experiment were prepared in the laboratory: 1) mechanically filtered in the in-water cleaning system (MF) and 2) additionally filtered with a 0.45 µm filter in the laboratory (LF). These wastewater samples contained high concentrations of metals (zinc and copper) and metal-based booster biocides (copper pyrithione and zinc pyrithione) compared to those analyzed in seawater. Polycheates were exposed to different concentrations of the two wastewater samples for 96 h. Higher mortality was observed in response to MF compared to LF-exposed polychaetes. Both wastewater samples dose-dependently decreased burrowing activity and AChE activity. Drastic oxidative stress was observed in response to the two wastewater samples. MDA levels were significantly increased by MF and LF samples. Significant GSH depletion was observed with MF exposure, while increased and decreased GSH contents were observed in LF-exposed polychaetes. Enzymatic activities of antioxidant components, catalase, superoxide dismutase, and glutathione S-transferase were significantly modulated by both wastewater samples. These results indicate that even filtered hull cleaning wastewater can have deleterious effects on the health status of polychaetes.

Hull-cleaning wastewater poses serious acute and chronic toxicity to a marine mysid-A multigenerational study.

We conducted a comprehensive assessment involving acute effects on 96-hour survival and biochemical parameters, as well as chronic effects on growth and reproduction spanning three generations of the marine mysid Neomysis awatschensis exposed to filtered wastewater to evaluate the potential impact of ship hull-cleaning wastewater on crustaceans. The analyzed wastewater exhibited elevated concentrations of metals, specifically zinc (Zn) and copper (Cu) and metal-based antifoulants, i.e., Cu pyrithoine (CuPT) and Zn pyrithoine (ZnPT). The results revealed dose-dependent reductions in survival rates, accompanied by a notable increase in oxidative stress, in response to the sublethal values of two wastewater samples: 1) mechanically filtered using the cleaning system (MF) and 2) additionally filtered in the laboratory (LF) for 96 h. Mysids exposed to MF displayed higher mortality than those exposed to LF. Furthermore, mysids subjected to continuous exposure of 0.001% LF across three generations exhibited significant inhibition of the feeding rate, more pronounced growth retardation along with an extended intermolt duration, and a diminished rate of reproduction compared to the control. A noteworthy inhibition of the feeding rate and growth was observed in the first generation exposed only to the LF sample. However, although the reproduction rate was not significantly affected. Collectively, these findings underscore the potential harm posed by sublethal concentrations of wastewater to the health of mysid populations under consistent exposure.

Detrimental effects of hull cleaning wastewater on oxidative status, life cycle parameters, and population growth of the monogonont rotifer Brachionus manjavacas.

While wastewater discharged from in-water cleaning process of ship hulls on rotifer consistently released into aquatic ecosystem, its detrimental effects on non-target animals are largely unclear. In this study, we provide evidence on detrimental effects of hull cleaning wastewater in the monogonont rotifer Brachionus manjavacas by analyzing biochemical and physiological parameters in its oxidative status, survival, lifespan, growth, fecundity, and population. The wastewater contained high concentrations of metals (Zn and Cu) and metal-based antifoulants (CuPT and ZnPT). Significant oxidative stress was observed in response to two wastewater samples [1) raw wastewater (RW) and 2) mechanical filtrated in the cleaning system (MF)]. Higher detrimental effects in survival, lifespan, fecundity, and population growth for 10 days were measured in the RW-exposed rotifers than those results analyzed in the MF-exposed rotifers. Two growth parameters, lorica length and width were also significantly modulated by both wastewater samples. These results indicate that even filtered hull cleaning wastewater would have deleterious effects on the maintenance of the rotifer population when they exposed constantly.

Rice (Oryza sativa L.) Grain Size, Shape, and Weight-Related QTLs Identified Using GWAS with Multiple GAPIT Models and High-Density SNP Chip DNA Markers.

This study investigated novel quantitative traits loci (QTLs) associated with the control of grain shape and size as well as grain weight in rice. We employed a joint-strategy multiple GAPIT (Genome Association and Prediction Integrated Tool) models [(Bayesian-information and Linkage-disequilibrium Iteratively Nested Keyway (BLINK)), Fixed and random model Circulating Probability Uniform (FarmCPU), Settlement of MLM Under Progressive Exclusive Relationship (SUPER), and General Linear Model (GLM)]-High-Density SNP Chip DNA Markers (60,461) to conduct a Genome-Wide Association Study (GWAS). GWAS was performed using genotype and grain-related phenotypes of 143 recombinant inbred lines (RILs). Data show that parental lines (Ilpum and Tung Tin Wan Hein 1, TTWH1, Oryza sativa L., ssp. japonica and indica, respectively) exhibited divergent phenotypes for all analyzed grain traits), which was reflected in their derived population. GWAS results revealed the association between seven SNP Chip makers and QTLs for grain length, co-detected by all GAPIT models on chromosomes (Chr) 1-3, 5, 7, and 11, were qGL1-1BFSG (AX-95918134, Chr1: 3,820,526 bp) explains 65.2-72.5% of the phenotypic variance explained (PVE). In addition, qGW1-1BFSG (AX-273945773, Chr1: 5,623,288 bp) for grain width explains 15.5-18.9% of PVE. Furthermore, BLINK or FarmCPU identified three QTLs for grain thickness independently, and explain 74.9% (qGT1Blink, AX-279261704, Chr1: 18,023,142 bp) and 54.9% (qGT2-1Farm, AX-154787777, Chr2: 2,118,477 bp) of the observed PVE. For the grain length-to-width ratio (LWR), the qLWR2BFSG (AX-274833045, Chr2: 10,000,097 bp) explains nearly 15.2-32% of the observed PVE. Likewise, the major QTL for thousand-grain weight (TGW) was detected on Chr6 (qTGW6BFSG, AX-115737727, 28,484,619 bp) and explains 32.8-54% of PVE. The qTGW6BFSG QTL coincides with qGW6-1Blink for grain width and explained 32.8-54% of PVE. Putative candidate genes pooled from major QTLs for each grain trait have interesting annotated functions that require functional studies to elucidate their function in the control of grain size, shape, or weight in rice. Genome selection analysis proposed makers useful for downstream marker-assisted selection based on genetic merit of RILs.

Genome-wide association study (GWAS) with high-throughput SNP chip DNA markers identified novel genetic factors for mesocotyl elongation and seedling emergence in rice (Oryza sativa L.) using multiple GAPIT models.

This study employed a joint strategy high-density SNP Chip DNA markers and multiple Genome Association and Prediction Integrated Tool (GAPIT) models [(Bayesian-information and Linkage-disequilibrium Iteratively Nested Keyway (BLINK), Fixed and random model Circulating Probability Uniform (FarmCPU), General Linear Model (GLM), and Settlement of Mixed Linear Model (MLM) Under Progressively Exclusive Relationship (SUPER)], to investigate novel genetic factors controlling mesocotyl elongation and seedling emergence for direct-seeded rice. Genotype data (230,526 SNP Chip DNA makers) of 117 doubled haploid lines (derived from a cross between 93-11 (Oryza sativa L. ssp. indica) and Milyang352 (O. sativa L. ssp. japonica) were used to perform a Genome-Wide Association Study (GWAS). Results revealed the association between five (5) topmost significant SNP markers, of which number two [AX-155741269, Chr2: 15422406 bp, and AX-155200917, Chr7: 23814085 bp, explaining 37.5% and 13.8% of the phenotypic variance explained (PVE)] are linked to the mesocotyl elongation loci, while three (AX-282097034 and AX-283652873, Chr9: 9882817 bp and 1023383 bp, PVE 64.5%, and 20.2%, respectively, and AX-154356231, Chr1: 17413989 bp, PVE 21.1%) are tightly linked to the loci controlling seedling emergence. The qMEL2-1 and qSEM9-1 are identified as major QTLs explaining 37.5% and 64.5% of the PVE for mesocotyl elongation and seedling emergence, respectively. The AX-282097034 (Chr9: 9882817 bp) was co-detected by four GAPIT models (BLINK, FarmCPU, SUPER, and GLM), while AX-155741269 was co-detected by BLINK and SUPER. Furthermore, a high estimated heritability (Mesocotyl elongation: h2 = 0.955; seedling emergence: h2 = 0.863; shoot length: h2 = 0.707) was observed. Genes harbored by qMEL2-1 and qSEM9-1 have interesting annotated molecular functions that could be investigated through functional studies to uncover their roles during mesocotyl elongation and seedling emergence events in rice. Furthermore, the presence of genes encoding transcription factors, growth- and stress response, or signaling-related genes would suggest that mesocotyl elongation and seedling emergence from deep direct-seeded rice might involve an active signaling cascade and transport of molecules, which could be elucidated through functional analysis. Likewise, genomic selection analysis suggested markers useful for downstream marker-assisted selection (MAS).

Acceleration of wheat breeding: enhancing efficiency and practical application of the speed breeding system.

BACKGROUND: Crop breeding should be accelerated to address global warming and climate change. Wheat (Triticum aestivum L.) is a major food crop. Speed breeding (SB) and speed vernalization (SV) techniques for spring and winter wheat have recently been established. However, there are few practical examples of these strategies being used economically and efficiently in breeding programs. We aimed to establish and evaluate the performance of a breeder-friendly and energy-saving generation acceleration system by modifying the SV + SB system. RESULTS: In this study, a four-generation advancement system for wheat (regardless of its growth habits) was established and evaluated using an energy-efficient extended photoperiod treatment. A glasshouse with a 22-hour photoperiod that used 10 h of natural sunlight and 12 h of LED lights, and minimized temperature control during the winter season, was successful in accelerating generation. Even with one or two field tests, modified speed breeding (mSB) combined with a speed vernalization system (SV + mSB) reduced breeding time by more than half compared to traditional field-based methods. When compared to the existing SV + SB system, the SV + mSB system reduced energy use by 80% to maintain a 22-hour photoperiod. Significant correlations were found between the SV + mSB and field conditions in the number of days to heading (DTH) and culm length (CL). Genetic resources, recombinant inbred lines, and breeding materials that exhibited shorter DTH and CL values under SV + mSB conditions showed the same pattern in the field. CONCLUSIONS: The results of our SV + mSB model, as well as its practical application in wheat breeding programs, are expected to help breeders worldwide incorporate generation acceleration systems into their conventional breeding programs.

Comparison of the effects of sublethal concentrations of biofoulants, copper pyrithione and zinc pyrithione on a marine mysid - A multigenerational study.

To determine the effect of copper pyrithione (CuPT) and zinc pyrithione (ZnPT), a set of acute (96 h-LC50) and chronic endpoints was studied in the marine mysid, Neomysis awatschensis. Based on the 1/10 NOECs and NOEC values calculated from 96 h-toxicity test, survival and growth, intermolt duration, feeding, and the number of newborn juveniles were measured by evaluating enzymatic activity of detoxification parameter glutathione S-transferase (GST) and cholinergic biomarker acetylcholinesterase (AChE) in the marine mysid exposed to 96 h-NOECs of CuPT and ZnPT for four weeks across three generations. Dose-dependent decreases in survival rate monitored for four weeks were observed with age-specific sensitivity in response to the 96 h-NOECs of both antifoulants. Higher growth retardation was observed with an increase in intermolt duration and inhibition of the feeding rate in CuPT-exposed mysid compared to ZnPT-exposed mysid across generations. The numbers of newborn juveniles significantly decreased at the third generation by exposure to the 96 h-NOECs of both antifoulants. GST activity was significantly inhibited in response to 96 h-NOECs of both antifoulants, whereas AChE activity was only reduced by the 96 h-NOECs of CuPT at the third generation. These results indicate that CuPT has a higher toxicity than ZnPT and even sublethal levels of CuPT and ZnPT would have detrimental effects on the maintenance of the mysid population. Finally, consistent exposure to environmentally relevant concentrations of CuPT and ZnPT can induce intergenerational toxicity in mysid.

The complete mitochondrial genome of the terebellid polychaete Neoamphitrite affinis (Polychaeta; Terebellidae).

Here, we sequenced and annotated the complete mitochondrial genome for the terebellid polychaete, Neoamphitrite affinis (Malmgren 1866). The complete mitogenome of N. affinis is 15,823 bp, with 33.4% A, 18.2% C, 11.5% G, and 37.0% T. The circular N. affinis mitochondrial genome comprises 13 protein-coding genes (PCGs), 23 transfer RNA (tRNA) genes including 2 methionine tRNA genes, 2 ribosomal RNA (rRNA) genes, and a non-coding region. Phylogenomic analysis based on 26 in-group taxa belonging to the two main clades, Sedentaria and Errantia, is congruent with published phylogenetic relationship for annelids, which N. affinis was grouped with Pista cristata (Terebellida; Terebellidae). This mitogenome resource will be useful for future phylogenetic studies of families belonging to Sedentaria.

Nitric oxide: A core signaling molecule under elevated GHGs (CO2, CH4, N2O, O3)-mediated abiotic stress in plants.

Nitric oxide (NO), an ancient molecule with multiple roles in plants, has gained momentum and continues to govern plant biosciences-related research. NO, known to be involved in diverse physiological and biological processes, is a central molecule mediating cellular redox homeostasis under abiotic and biotic stresses. NO signaling interacts with various signaling networks to govern the adaptive response mechanism towards stress tolerance. Although diverging views question the role of plants in the current greenhouse gases (GHGs) budget, it is widely accepted that plants contribute, in one way or another, to the release of GHGs (carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O) and ozone (O3)) to the atmosphere, with CH4 and N2O being the most abundant, and occur simultaneously. Studies support that elevated concentrations of GHGs trigger similar signaling pathways to that observed in commonly studied abiotic stresses. In the process, NO plays a forefront role, in which the nitrogen metabolism is tightly related. Regardless of their beneficial roles in plants at a certain level of accumulation, high concentrations of CO2, CH4, and N2O-mediating stress in plants exacerbate the production of reactive oxygen (ROS) and nitrogen (RNS) species. This review assesses and discusses the current knowledge of NO signaling and its interaction with other signaling pathways, here focusing on the reported calcium (Ca2+) and hormonal signaling, under elevated GHGs along with the associated mechanisms underlying GHGs-induced stress in plants.

Exposure to Environmentally Relevant Concentrations of Polystyrene Microplastics Increases Hexavalent Chromium Toxicity in Aquatic Animals.

The prevalence of hexavalent chromium [Cr(VI)] and microplastics (MPs) is ubiquitous and is considered a threat to aquatic biota. MPs can act as a vector for waterborne metals; however, the combined effects of Cr(VI) and MPs on aquatic organisms are largely unknown. In this study, aquatic model animals, such as rotifers (Brachionus calyciflorus and B. plicatilis), water fleas (Daphnia magna), amphipods (Hyalella azteca), polychaetes (Perinereis aibuhitensis), and zebrafish (Danio rerio) were exposed to environmental concentrations (1, 10, and 100 particles L-1) of 1 µm polystyrene MPs alone, Cr(VI) alone, or Cr(VI) combined with MPs. Following exposure, the potential effects were measured by analyzing basic life endpoints (e.g., survival rate and growth). A significant response to MPs alone was not observed in all animals. However, MPs combined with Cr(VI) concentration-dependently increased Cr(VI) toxicity in two rotifer species. The survival rate of water fleas was significantly reduced upon exposure to Cr(VI) + MPs (100 particles L-1) compared with exposure to Cr(VI) alone, and significantly decreased the number of offspring. Although there was no significant effect on the body length of the amphipod, concentration-dependent decreases in their survival rates were observed. In contrast, no significant change was found in the survival rate of polychaetes; however, their burrowing ability was inhibited by Cr(VI) + MPs (100 particles L-1). Further, larval mortality was increased in response to Cr(VI) + MPs (100 particles L-1) in zebrafish. Taken together, the findings suggest that MPs can exacerbate Cr(VI) toxicity, even at environmental levels.

Multiple Facets of Nitrogen: From Atmospheric Gas to Indispensable Agricultural Input.

Nitrogen (N) is a gas and the fifth most abundant element naturally found in the atmosphere. N's role in agriculture and plant metabolism has been widely investigated for decades, and extensive information regarding this subject is available. However, the advent of sequencing technology and the advances in plant biotechnology, coupled with the growing interest in functional genomics-related studies and the various environmental challenges, have paved novel paths to rediscovering the fundamentals of N and its dynamics in physiological and biological processes, as well as biochemical reactions under both normal and stress conditions. This work provides a comprehensive review on multiple facets of N and N-containing compounds in plants disseminated in the literature to better appreciate N in its multiple dimensions. Here, some of the ancient but fundamental aspects of N are revived and the advances in our understanding of N in the metabolism of plants is portrayed. It is established that N is indispensable for achieving high plant productivity and fitness. However, the use of N-rich fertilizers in relatively higher amounts negatively affects the environment. Therefore, a paradigm shift is important to shape to the future use of N-rich fertilizers in crop production and their contribution to the current global greenhouse gases (GHGs) budget would help tackle current global environmental challenges toward a sustainable agriculture.

Acute and mutigenerational effects of environmental concentration of the antifouling agent dichlofluanid on the mysid model, Neomysis awatschensis.

A broad-spectrum fungicide, dichlofluanid is widely used in antifouling paints and agricultural pesticides. In this study, the acute and chronic effects of sublethal concentrations, namely, no observable effect concentration (NOEC) and 50% lethal concentration (LC50) of dichlofluanid (1/10 NOEC, NOEC, 1/10 LC50, and LC50) were evaluated on the marine mysid, Neomysis awatschensis. Acute toxicity test (96 h) showed higher sensitivity to dichlofluanid in juvenile mysids (LC50 3.1 µg L-1) than adults (LC50 24.5 µg L-1), with lower survival rate and reduction in food consumption. Exposure with dichlofluanid considerably induced oxidative imbalance, as NOEC (0.006 µg L-1 for juveniles and 0.074 µg L-1 for adults) and 1/10 LC50 values increased intracellular concentrations of malondialdehyde and glutathione, and the enzymatic activities of catalase and superoxide dismutase, whereas exposure to LC50 value decreased the values of oxidative parameters. Enzymatic activity of acetylcholinesterase decreased considerably when exposed to LC50 value. In the case of chronic effects, exposure to NOEC for 4 weeks markedly decreased the juvenile survival rate, while adults showed tolerance. Multigenerational monitoring in response to NOEC showed a significant growth retardation with an increase in intermolt duration as well as a decrease in the number of newborn mysids from females of the third generation. Consistent exposure to environmentally relevant sublethal concentrations of dichlofluanid would be detrimental to mysid individuals and the survival of the mysid population.

Speed vernalization to accelerate generation advance in winter cereal crops.

There are many challenges facing the development of high-yielding, nutritious crops for future environments. One limiting factor is generation time, which prolongs research and plant breeding timelines. Recent advances in speed breeding protocols have dramatically reduced generation time for many short-day and long-day species by optimizing light and temperature conditions during plant growth. However, winter crops with a vernalization requirement still require up to 6-10 weeks in low-temperature conditions before the transition to reproductive development. Here, we tested a suite of environmental conditions and protocols to investigate whether the vernalization process can be accelerated. We identified a vernalization method consisting of exposing seeds at the soil surface to an extended photoperiod of 22 h day:2 h night at 10°C with transfer to speed breeding conditions that dramatically reduces generation time in both winter wheat (Triticum aestivum) and winter barley (Hordeum vulgare). Implementation of the speed vernalization protocol followed by speed breeding allowed the completion of up to five generations per year for winter wheat or barley, whereas only two generations can be typically completed under standard vernalization and plant growth conditions. The speed vernalization protocol developed in this study has great potential to accelerate biological research and breeding outcomes for winter crops.

Reductive Transformation of Hexavalent Chromium in Ice Decreases Chromium Toxicity in Aquatic Animals.

In this study, the toxicity of hexavalent chromium [Cr(VI)] reduced by citric acid in ice was measured using representative aquatic model invertebrates (i.e., rotifer, water flea, amphipod, and polychaete) and a vertebrate (zebrafish) by analyzing short- and/or long-term endpoints that are frequently applied to each animal. Cr(VI) reduction in the presence of citric acid was markedly enhanced in the ice phase compared to that in an aqueous solution through the freeze concentration effect. The highly concentrated Cr(VI) and citric acid in ice grain boundaries were also confirmed using in situ cryogenic confocal Raman spectroscopy. Overall, exposure to Cr(VI) resulted in higher acute and/or chronic effects on aquatic animals, such as drastic mortality, growth inhibition, and decrease in offspring number, whereas the animals were increasingly tolerant to Cr(VI) that was reduced in the ice phase. Sublethal concentrations of Cr(VI) significantly decreased the antioxidant capacity in the aquatic animals. However, when the same concentrations of Cr(VI) were reduced in ice, these treatments showed no modulation or increase in the antioxidant defense system. Taken together, our results suggest that Cr(VI) reduction into Cr(III) was successfully achieved in ice and that this methodology can decrease the actual toxicity of Cr(VI) in aquatic animals.

Long-term exposure to antifouling biocide chlorothalonil modulates immunity and biochemical and antioxidant parameters in the blood of olive flounder.

In this study, the potential effects of 30-day exposure to environmentally relevant concentrations of chlorothalonil (0, 5, 10, and 20 µg L-l) were tested in the blood of the economically important olive flounder, Paralichthys olivaceus, using biochemical endpoints. Significant decreases in the enzymatic activities of immunity markers, alternative complements, and lysozymes were detected in the fish exposed to 10 or 20 µg L-l of chlorothalonil at day 20 or 30. The total immunoglobulin content was lowered in response to 20 µg L-l chlorothalonil at day 10 and 20, even when later exposed to 5 µg L-l at day 30. Among the essential blood components, the cortisol level was increased in response to chlorothalonil throughout the study with a decrease in white blood cells, while no changes were observed in hemoglobin, red blood cells, total protein concentration, and glucose in all exposures. The enzymatic activities of the three hepatic toxicity markers, alanine transferases, aspartate transaminase, and alkaline phosphatase, increased by 10 and/or 20 µg L-l of chlorothalonil. Significant oxidative stress was induced by chlorothalonil in the fish exposed to 10 or 20 µg L-l of chlorothalonil, as revealed by increased malondialdehyde and fluctuating glutathione levels with increase in the enzymatic activities of antioxidant defense system, including catalase and superoxide dismutase, during exposure. Taken together, these results suggest that long-term exposure to environmentally relevant concentrations of chlorothalonil can affect susceptibility to pathogens through immunosuppression, hepatic toxicity, and oxidative stress in olive flounder. These results can contribute to the monitoring of aquatic environments and ecotoxicological research through the measurement of blood components against waterborne chlorothalonil.

Novel QTL Associated with Aerenchyma-Mediated Radial Oxygen Loss (ROL) in Rice (Oryza sativa L.) under Iron (II) Sulfide.

In rice, high radial oxygen loss (ROL) has been associated with the reduction in the activity of methanogens, therefore reducing the formation of methane (CH4) due to the abundance in application of nitrogen (N)-rich fertilizers. In this study, we evaluated the root growth behavior and ROL rate of a doubled haploid (DH) population (n = 117) and parental lines 93-11 (P1, indica) and Milyang352 (P2, japonica) in response to iron (II) sulfide (FeS). In addition, we performed a linkage mapping and quantitative trait locus (QTL) analysis on the same population for the target traits. The results of the phenotypic evaluation revealed that parental lines had distinctive root growth and ROL patterns, with 93-11 (indica) and Milyang352 (japonica) showing low and high ROL rates, respectively. This was also reflected in their derived population, indicating that 93.2% of the DH lines exhibited a high ROL rate and about 6.8% had a low ROL pattern. Furthermore, the QTL and linkage map analysis detected two QTLs associated with the control of ROL and root area on chromosomes 2 (qROL-2-1, 127 cM, logarithm of the odds (LOD) 3.04, phenotypic variation explained (PVE) 11.61%) and 8 (qRA-8-1, 97 cM, LOD 4.394, PVE 15.95%), respectively. The positive additive effect (2.532) of qROL-2-1 indicates that the allele from 93-11 contributed to the observed phenotypic variation for ROL. The breakthrough is that the qROL-2-1 harbors genes proposed to be involved in stress signaling, defense response mechanisms, and transcriptional regulation, among others. The qPCR results revealed that the majority of genes harbored by the qROL-2-1 recorded a higher transcript accumulation level in Milyang352 over time compared to 93-11. Another set of genes exhibited a high transcript abundance in P1 compared to P2, while a few were differentially regulated between both parents. Therefore, OsTCP7 and OsMYB21, OsARF8 genes encoding transcription factors (TFs), coupled with OsTRX, OsWBC8, and OsLRR2 are suggested to play important roles in the positive regulation of ROL in rice. However, the recorded differential expression of OsDEF7 and OsEXPA, and the decrease in OsNIP2, Oscb5, and OsPLIM2a TF expression between parental lines proposes them as being involved in the control of oxygen flux level in rice roots.

RNA-Seq and Electrical Penetration Graph Revealed the Role of Grh1-Mediated Activation of Defense Mechanisms towards Green Rice Leafhopper (Nephotettix cincticeps Uhler) Resistance in Rice (Oryza sativa L.).

The green rice leafhopper (GRH, Nephotettix cincticeps Uhler) is one of the most important insect pests causing serious damage to rice production and yield loss in East Asia. Prior to performing RNA-Seq analysis, we conducted an electrical penetration graph (EPG) test to investigate the feeding behavior of GRH on Ilpum (recurrent parent, GRH-susceptible cultivar), a near-isogenic line (NIL carrying Grh1) compared to the Grh1 donor parent (Shingwang). Then, we conducted a transcriptome-wide analysis of GRH-responsive genes in Ilpum and NIL, which was followed by the validation of RNA-Seq data by qPCR. On the one hand, EPG results showed differential feeding behaviors of GRH between Ilpum and NIL. The phloem-like feeding pattern was detected in Ilpum, whereas the EPG test indicated a xylem-like feeding habit of GRH on NIL. In addition, we observed a high death rate of GRH on NIL (92%) compared to Ilpum (28%) 72 h post infestation, attributed to GRH failure to suck the phloem sap of NIL. On the other hand, RNA-Seq data revealed that Ilpum and NIL GRH-treated plants generated 1,766,347 and 3,676,765 counts per million mapped (CPM) reads, respectively. The alignment of reads indicated that more than 75% of reads were mapped to the reference genome, and 8859 genes and 15,815,400 transcripts were obtained. Of this number, 3424 differentially expressed genes (DEGs, 1605 upregulated in Ilpum and downregulated in NIL; 1819 genes upregulated in NIL and downregulated in Ilpum) were identified. According to the quantile normalization of the fragments per kilobase of transcript per million mapped reads (FPKM) values, followed by the Student's t-test (p < 0.05), we identified 3283 DEGs in Ilpum (1935 upregulated and 1348 downregulated) and 2599 DEGs in NIL (1621 upregulated and 978 downregulated) with at least a log2 (logarithm base 2) twofold change (Log2FC ≥2) in the expression level upon GRH infestation. Upregulated genes in NIL exceeded by 13.3% those recorded in Ilpum. The majority of genes associated with the metabolism of carbohydrates, amino acids, lipids, nucleotides, the activity of coenzymes, the action of phytohormones, protein modification, homeostasis, the transport of solutes, and the uptake of nutrients, among others, were abundantly upregulated in NIL (carrying Grh1). However, a high number of upregulated genes involved in photosynthesis, cellular respiration, secondary metabolism, redox homeostasis, protein biosynthesis, protein translocation, and external stimuli response related genes were found in Ilpum. Therefore, all data suggest that Grh1-mediated resistance against GRH in rice would involve a transcriptome-wide reprogramming, resulting in the activation of bZIP, MYB, NAC, bHLH, WRKY, and GRAS transcription factors, coupled with the induction of the pathogen-pattern triggered immunity (PTI), systemic acquired resistance (SAR), symbiotic signaling pathway, and the activation of genes associated with the response mechanisms against viruses. This comprehensive transcriptome profile of GRH-responsive genes gives new insights into the molecular response mechanisms underlying GRH (insect pest)-rice (plant) interaction.

Characterization and phylogenetic analysis of the complete mitochondrial genome of the polychaete, Melinna cristata.

In this study, we report the complete mitogenome sequence of the polychaete, Melinna cristata (Sars, 1851). The circular M. cristata mitochondrial genome is 15,696 bp in length and has an AT content of 66%. As in other polychaetes, the genome has 13 protein-coding genes (PCGs), two ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA) genes, and a non-coding region. Gene composition and their order in the M. cristata mitochondrion are identical to the Terebelliformia mitogenomes. A maximum-likelihood gene tree based on the M. cristata mitogenome combined with previously published Sedentaria and Errantia mitogenomes revealed that M. cristata forms a clade with two Terebelliformia species.