Higher MDA Content Research Articles

Effects of dietary defatted black soldier fly (Hermetia illucens) larvae meal substituting fish meal on growth, antioxidative capacity, immunity, intestinal histology and microbiota of juvenile Chinese mitten crab (Eriocheir sinensis)

This study evaluated the effects of replacing dietary fish meal (FM) with defatted black soldier fly (Hermetia illucens) larvae meal (DBSFLM) on growth, non-specific immunity, antioxidative capacity, intestinal histology and microbiota of juvenile Chinese mitten crab (Eriocheir sinensis). A control diet was designed to contain 200 g/kg FM (Con), then 25 %, 50 %, 75 %, and 100 % of dietary FM was replaced by DBSFLM, referring to DBSFLM25, DBSFLM50, DBSFLM75 and DBSFLM100, respectively. The five isoproteic and isolipidic diets were fed to crab (7.15 ± 0.10 g) for 8 weeks. The results indicated that the final weight, weight gain, feed conversion ratio and survival of DBSFLM25 and DBSFLM50 groups all reached the same level as Con (P > 0.05). The proper DBSFLM replacement on WG and FCR from broken line model were 49.70 % and 52.90 %, respectively. For immune enzyme activity, ACP, ALP, and LZM activities showed a trend of first increasing and then decreasing, the DBSFLM50 group had the highest activity, and the DBSFLM100 group was significantly lower than the DBSFLM50 group (P < 0.05). In terms of antioxidant capacity, the T-AOC, T-SOD, GSH-Px activities and MDA content of DBSFLM25 DBSFLM50 and DBSFLM75 groups all shows no significant difference with Con (P > 0.05), the DBSFLM100 group has the lowest antioxidant enzyme activities and highest MDA content. The intestinal number of folds and folds height in DBSFLM25 and DBSFLM50 groups reached the same level as Con (P > 0.05). The abundance of intestinal harmful bacteria Vibrio was enhanced with the increase of dietary DBSFLM level (P < 0.05). In conclusion, the recommended level of replacing FM with DBSFLM was at 50 % (100 g/kg) without negative effect on growth, non-specific immunity, antioxidative capacity, intestinal histology and microbiota of Chinese mitten crab.

The Impact of Drought and Salinity Stress on the Physiological Growth of Fontanesia Fortunei Carr.

In order to understand the drought resistance and salt tolerance of maple leaves of Fontanesia fortunei Carr. In this study, seeds of Fontanesia fortunei Carr. were treated with different concentrations of PEG and NaCl solutions to investigate their effects on growth and physiology. The results demonstrated that the control group had the highest germination rate. PEG had a significant impact on root length but a minimal influence on plant height, with mild drought stress promoting root growth. Increasing concentrations of PEG were associated with higher MDA content, peaking at 10% concentration, while SOD activity reached its maximum at 10% PEG concentration. When the NaCl concentration was 0%, seedling root length and plant height were both maximized. NaCl primarily influenced root length but had a minor effect on plant height. Maximum MDA content was observed at 0.8% NaCl concentration, whereas SOD activity reached its peak at 0.6% NaCl concentration. This study has significant implications for landscape architecture and horticultural production.

Comparative analyses of D-fenchone and MENA inhibited sprouting of sweet potato storage roots

Postharvest sprouting is a major problem for the storage of sweet potato. This study compared the effect of D-fenchone with methyl naphthacetate (MENA) treatments on the sprouting of ‘Yan 25′ sweet potato. The untreated control roots sprouted within 4 days however the roots fumigated with 200 μL / 23 L D-fenchone or MENA completely inhibited the sprouting of freshly harvested ‘Yan 25′ during 14 days storage at 30 ℃. Furthermore, treating established sprouts (0.5 cm) with MENA or D-fenchone resulted in damaged sprouts after seven days following treatment with higher MDA content and these sprouts eventually died. Transcriptomic analyses revealed that both D-fenchone and MENA inhibited cell wall synthesis and disrupted auxin and cytokinin pathways in the storage roots, by which suppressed the sprouting. The RNA-seq results of established sprouts showed that both D-fenchone and MENA promoted ethylene and reactive oxidative species (ROS) pathways, which were correlated with the physical damage. In addition, D-fenchone and MENA inhibited auxin pathway, MENA changed cytokinin and D-fenchone disrupted polyamine, cell division and cellulose biosynthesis pathways which all may have contributed to sprout suppression.

Different Starch Sources Affect the Growth Performance and Hepatic Health Status of Largemouth Bass (Micropterus salmoides) in a High-Temperature Environment.

The experiment was designed to investigate the effects of different starch types on the growth performance and liver health status of largemouth bass in a high-temperature environment (33-35 °C). In this study, we designed five diets using corn starch (CS), tapioca starch (TS), sweet potato starch (SPS), potato starch (PS), and wheat starch (WS) as the starch sources (10%). We selected 225 healthy and uniformly sized largemouth bass (199.6 ± 0.43 g) and conducted the feeding experiment for 45 days. The results showed that the WS group had the highest WGR, SGR, and SR and the lowest FCR. Among the five groups, the WS group had the highest CAT activity, SOD activity, and GSH content, while the SPS group had the highest MDA content. Furthermore, oil red O staining of liver samples showed that the TS group had the largest positive region, indicating high lipid accumulation. Lastly, the gene expression results revealed that compared with the WS group, the CS, TS, and SPS groups showed suppressed expression of nrf2, keap1, cat, sod, gpx, il-8, and il-10. Therefore, our results demonstrated the effect of different starch sources on largemouth bass growth performance and hepatic health in a high-temperature environment.

Physiological and autophagy evaluation of different pear varieties (Pyrus spp.) in response to Botryosphaeria dothidea infection.

Ring rot disease is one of the most common diseases in pear orchards. To better understand the physiology, biochemistry and autophagic changes of different pear varieties after Botryosphaeria dothidea (B.dothidea) infection, we evaluated eight different pear varieties for B. dothidea resistance. The susceptible varieties had larger spot diameters, lower chlorophyll contents and higher malondialdehyde contents than the resistant varieties. In disease-resistant varieties, reactive oxygen species (ROS) levels were relatively lower, while the ROS metabolism (antioxidant enzyme activities and the ascorbic acid-glutathione cycle) was also maintained at higher levels, and it induced a significant upregulation of related gene expression. In addition, autophagy, as an important evaluation index, was found to have more autophagic activity in disease-resistant varieties than in susceptible varieties, suggesting that pathogen infestation drives plants to increase autophagy to defend against pathogens. In summary, the results of this study reveal that different resistant pear varieties enhance plant resistance to the disease through a series of physio-biochemical changes and autophagic activity after inoculation with B. dothidea. This study provides clear physiological and biochemical traits for pear disease resistance selection, potential genetic resources and material basis for pear disease control and disease resistance, breeding and points out the direction for research on the mechanism of pear resistance to B. dothidea.

Metabolomic Analysis of Arabidopsis ost1-4 Mutant Revealed the Cold Response Regulation Mechanisms by OPEN STOMATA 1 (OST1) at Metabolic Level

Cold stress is one of the major abiotic stresses that limits the growth and development of plants. Improving the cold tolerance of plants is essential to enhance crop productivity in the changing environment. OPEN STOMATA 1 (OST1), also known as sucrose non-fermenting 1 related protein kinases 2.6/2E (SnRK2.6/SnRK2E), has been reported to involved in cold stress response in plants. This interesting protein is confined to expressed in guard cells and vascular system. However, the detailed mechanism of how OST1 regulates cold stress, especially at the metabolomic level is largely unknown. In this study, metabolomic profiling of ost1 mutant and WT Arabidopsis plants under cold stress was investigated. The results showed that ost1-4 mutants displayed cold sensitive phenotypes compared with the WT plant, as evidenced by higher MDA content and electrolyte leakage and lower photosynthetic characteristics. Next, the metabolic changes between ost1-4 and WT plants in response to cold stress was analyzed by using the GC-TOF-MS system. The results showed that numbers of metabolites were identified to be related to OST1 regulated cold stress response. A large portion of the metabolites were carbohydrates and organic acids. The KEGG enrichment analysis revealed that the alanine, aspartate and glutamate metabolism, cyanoamino acid metabolism and citrate cycle (TCA cycle) were presumptive pathways that most related to OST1 regulated cold stress response. Gene expression such as AtGDHs, AtPPC1 and AtAK1 was also in line with the metabolic changes in the presumed pathways. Overall, this study provides fundamental knowledge for understanding the underlying metabolic mechanisms of OST1 mediated cold stress response in plants.

Transcriptomic analyses of carvone inhibited sprouting in sweet potato (Ipomoea batatas (L.) Lam cv ‘Yan 25′) storage roots

Sprouting is an important postharvest problem in the transport and storage of sweet potato. This study investigated the effect of carvone fumigation on the development of sprouts in ‘Yan 25′ sweet potato storage roots and sprouts. The results showed that visible buds could be observed in untreated root after 4 d at 30 ℃, however no buds were found on carvone treated sweet potato, even after 14 d storage. The levels of β-amylase activity were lower in the carvone treated roots and were associated with higher starch content. Treatment of sweet potato sprouts with carvone severely damaged the sprouts after 24 h and finally turned black after 72 h treatment, resulting in higher MDA content. The transcriptomic analyses showed that the manipulation of auxin distribution, cytokinin metabolism, cell wall synthesis and cell wall loosening processes were associated with carvone inhibition of sprouting in sweet potato roots. Further transcriptomic analyses on sweet potato sprouts revealed a similar transcription profile except that the gibberellin metabolism was also affected in the sprouts by carvone treatment. The up-regulation of apoptosis related genes in carvone treated sprouts, included UDP-D-apiose/UDP-D-xylose synthase (UAXS), ACC oxidase (ACO), tonoplast intrinsic protein (TIP), respiratory burst oxidase (RBOH), senescence associated gene (SAG) which were correlated with the lethal effect of carvone on the sprout. Two conceptual models elucidating the molecular mechanism of carvone inhibited sprouting in sweet potato are proposed. The further elucidation of this mechanism will potentially lead to a theory to optimize the method in sprouting inhibition of sweet potato.

DNP and ATP regulate the pulp breakdown development in Phomopsis longanae Chi-infected longan fruit through modulating the ROS metabolism.

Compared with the P. longanae-infected longan, the DNP-treated P. longanae-infected fruit represented a higher pulp breakdown index, a higher O2 -. production rate, and a higher MDA content, but the lower activities of APX, SOD and CAT, the lower transcript levels of DlAPX6, DlSOD1, DlSOD2, DlSOD3 and DlCAT1, the lower values of AsA, GSH, flavonoid and total phenolics, a lower scavenging ability of DPPH radical, and a lower value of reducing power. Whereas, the ATP-treated P. longanae-infected samples showed the contrary results. The above findings indicated that the DNP-promoted the pulp breakdown in P. longanae-infected longan was because DNP weakened the capacity of scavenging ROS, raised the O2 -. level, and accelerated the membrane lipids peroxidation. However, the ATP-suppressed the pulp breakdown in P. longanae-infected longan was because ATP improved the capacity of scavenging ROS, reduced the O2 -. level, and reduced the membrane lipids peroxidation.

The Phytoremediation Potential and Physiological Adaptive Response of Tamarix tetrandra Pall. Ex M. Bieb. during the Restoration of Chronosequence Fly Ash Deposits

The challenging process of identifying and selecting plant species suited to the phytoremediation of fly ash (FA) dumps involves studying their functional properties and physiological response to a deficit of essential elements and toxicity from heavy metal(loid)-induced oxidative stress. We hypothesised that Tamarix tetrandra has high potential to be used for the phytoremediation of FA deposit sites thanks to its secretion strategy and antioxidative system. In this study, this hypothesis was examined by determining the bioconcentration and translocation factors for As, B, Cr, Cu, Mn, Ni, Se and Zn at the FA disposal lagoons at the ‘Nikola Tesla A’ thermal power plant in Obrenovac, Serbia, three (lagoon L1) and eleven (lagoon L2) years after the phytoremediation process had begun, and by measuring parameters of photosynthetic efficiency and chlorophyll concentration, non-enzymatic antioxidant defence (carotenoids, anthocyanins and phenolics), oxidative stress (concentration of malondialdehyde—MDA) and total antioxidant capacity to neutralise DPPH free radical activity. Tamarisk not only showed the ability to phytostabilise As, Cr and Ni and to accumulate low-availability Mn, Zn and Cu, but also the potential to maintain the structural and functional integrity of cell membranes and stable vitality at L1 under multiple stress conditions due to the high synthesis of phenols and tolerance to increased salinity. However, toxic concentrations of B and Se in leaves induced oxidative stress in tamarisk at L2 (reflected in higher MDA content and lower vitality) and also decreased the synthesis of chlorophyll, carotenoids, anthocyanins and total antioxidant activity. In addition, the prooxidative behaviour of phenols in the presence of spin-stabilising metals from FA could also have resulted in their weaker antioxidant protection at L2. These findings indicate that the choice of tamarisk was justified, but only at the beginning of the phytoremediation process because its presence contributed to an improvement in the harsh conditions at FA deposit sites and the creation of more favourable conditions for new plant species. This knowledge can be of great importance when planning sustainable ash deposit site management worldwide.

PpNUDX8, a Peach NUDIX Hydrolase, Plays a Negative Regulator in Response to Drought Stress.

Drought stress is a serious abiotic stress source that affects the growth and fruit quality of peach trees. However, the molecular mechanism of the NUDIX hydrolase family in peaches in response to drought stress is still unclear. Here, we isolated and identified the PpNUDX8 (Prupe.5G062300.1) gene from the peach NUDIX hydrolase family, and found that PpNUDX8 has a typical NUDIX hydrolase domain. In this study, we performed 15% PEG6000 drought treatment on peach seedlings, and qRT–PCR analysis showed that 15% PEG6000 induced the transcription level of PpNUDX8. Overexpression of PpNUDX8 reduced the tolerance of calli to 4% PEG6000 treatment. Compared with wild-type apple calli, PpNUDX8 transgenic apple calli had a lower fresh weight and higher MDA content. After 15% PEG6000 drought treatment, PpNUDX8 transgenic tobacco had a greater degree of wilting and shorter primary roots than Under control conditions. The chlorophyll, soluble protein, and proline contents in the transgenic tobacco decreased, and the MDA content and relative conductivity increased. At the same time, PpNUDX8 negatively regulated ABA signal transduction and reduced the transcriptional expression of stress response genes. In addition, PpNUDX8 was not sensitive to ABA, overexpression of PpNUDX8 reduced the expression of the ABA synthesis-related gene NCED6 and increases the expression of the ABA decomposition-related gene CYP1 in tobacco, which in turn leads to a decrease in the ABA content in tobacco. In addition, Under control conditions, overexpression of PpNUDX8 destroyed the homeostasis of NAD and reduced nicotinamide adenine dinucleotide (NADH) in tobacco. After 15% PEG6000 drought treatment, the changes in NAD and NADH in PpNUDX8 transgenic tobacco were more severe than those in WT tobacco. In addition, PpNUDX8 also interacted with PpSnRk1γ (Prupe.6G323700.1).

Physiological, Biochemical and Transcriptomic Analysis of the Aerial Parts (Leaf-Blade and Petiole) of Asarum sieboldii Responding to Drought Stress.

Asarum sieboldii Miq. is a leading economic crop and a traditional medicinal herb in China. Leaf-blade and petiole are the only aerial tissues of A. sieboldii during the vegetative growth, playing a vital role in the accumulation and transportation of biomass energy. They also act as critical indicators of drought in agricultural management, especially for crops having underground stems. During drought, variations in the morphology and gene expression of the leaves and petioles are used to control agricultural irrigation and production. Besides, such stress can also alter the differential gene expression in these tissues. However, little is known about the drought-tolerant character of the aerial parts of A. sieboldii. In this study, we examined the physiological, biochemical and transcriptomic responses to the drought stress in the leaf blades and petioles of A. sieboldii. The molecular mechanism, involving in drought stress response, was elucidated by constructing the cDNA libraries and performing transcriptomic sequencing. Under drought stress, a total of 2912 and 2887 unigenes were differentially expressed in the leaf blade and petiole, respectively. The detection of many transcription factors and functional genes demonstrated that multiple regulatory pathways were involved in drought tolerance. In response to drought, the leaf blade and petiole displayed a general physiological character, a higher SOD and POD activity, a higher MDA content and lower chlorophyll content. Three unigenes encoding POD were up-regulated, which can improve POD activity. Essential oil in petiole was extracted. The relative contents of methyleugenol and safrole in essential oil were increased from 0.01% to 0.05%, and 3.89% to 16.97%, respectively, while myristicin slightly reduced from 24.87% to 21.52%. Additionally, an IGS unigene, involved in eugenol biobiosynthesis, was found up-regulated under drought stress, which was predicated to be responsible for the accumulation of methyleugenol and safrole. Simple sequence repeats (SSRs) were characterized in of A. sieboldii, and a total of 5466 SSRs were identified. Among them, mono-nucleotides were the most abundant repeat units, accounting for 44.09% followed by tri-, tetra-, penta and hexa-nucleotide repeats. Overall, the present work provides a valuable resource for the population genetics studies of A. sieboldii. Besides, it provides much genomic information for the functional dissection of the drought-resistance in A. sieboldii, which will be useful to understand the bio-regulatory mechanisms linked with drought-tolerance to enhance its yield.

Seed-priming with H2O2 alleviates subsequent salt stress by preventing ROS production and amplifying antioxidant defense in cauliflower seeds and seedlings

In the present study, we examined the impact of three seed priming agents; H2O2, GA3 and NaCl on the oxidative stress status in primed seed germination dynamics and growth establishment of cauliflower seedlings subsequently grown under salt stress. Results showed beneficial effect of all priming agents in improving plant responses to salinity. However, specific differences, depending on development stage, organ and priming type were recorded. At the germination stage, GA3 was the most advantageous agent to accelerate seedling emergence. At the seedling stage, seedlings obtained from redried H2O2-primed seeds showed the highest level of seed superoxide anion (5-fold) and H2O2 (4-fold), resulting in higher MDA content (2.4-fold). At the same time, priming seeds with H2O2 triggered the overall seedling antioxidant defense, including enzymatic (SOD, CAT, GPX and APX) and non-enzymatic systems (AsA, GSH and proline). Salinity restricted the growth of both leaves (43%) and roots (60%) of cauliflower seedlings issued from unprimed seeds. Under primed conditions, the relative contribution of GA3 and NaCl was more associated with growth establishment and osmotic adjustment. However, H2O2 role was greatly correlated with the antioxidant defense. Indeed, salt-treated seedlings issued from H2O2-primed seeds showed the lowest levels of superoxide anion, H2O2 and MDA, resulting in the highest activities of the entire antioxidant systems. These findings support the hypothesis that cauliflower plants, when exposed to salt stress benefit from H2O2 seed priming, as a pre-germination stimulus, to prevent itself from subsequent oxidative injuries, which supports the hypothesis of “stress memory” of subsequent salt stress.

Overexpression of the rice ORANGE gene OsOR negatively regulates carotenoid accumulation, leads to higher tiller numbers and decreases stress tolerance in Nipponbare rice

The ORANGE (OR) gene has been reported to regulate chromoplast differentiation and enhance carotenoid biosynthesis in many dicotyledonous plants. However, the function of the OR gene in monocotyledons, especially rice, is poorly known. Here, the OR gene from rice, OsOR, was isolated and characterized by generating overexpressing and genome editing mutant lines. The OsOR-overexpressing plants exhibited pleiotropic phenotypes, such as alternating transverse green and white sectors on leaves at the early tillering stage, that were due to changes in thylakoid development and reduced carotenoid content. In addition, the number of tillers significantly increased in OsOR-overexpressing plants but decreased in osor mutant lines, a result similar to that previously reported for the carotenoid isomerase mutant mit3. The expression of the DWARF3 and DWARF53 genes that are involved in the strigolactone signalling pathway were similarly downregulated in OsOR-overexpressing plants but upregulated in osor mutants. Moreover, the OsOR-overexpressing plants exhibited greater sensitivity to salt and cold stress, and had lower total chlorophyll and higher MDA contents. All results suggest that the OsOR gene plays an important role not only in carotenoid accumulation but also in tiller number regulation and in responses to environmental stress in rice.

Timing and intensity of upregulated defensive enzymes is a key factor determining resistance in chickpea to Ascochyta rabiei

Ten genotypes comprising five resistant genotypes namely PBG 7, GLK 08–104 and GL 12021 (desi), ILWC 292 and C. judaicum 182 (wild); one moderately resistant genotype HC 5 (desi); three susceptible genotypes GLK 14313 and L552 (kabuli) and C. pinnatifidum 212 (wild) and one highly susceptible wild genotype ILWC 115 characterized on the basis of disease severity scale to Ascochyta blight caused by infection of Ascochyta rabiei were investigated for elicited biochemical responses. These genotypes were sown separately in Ascochyta screening plot and in control plot under normal conditions to study the response of enzymatic antioxidants and signalling molecules in leaves at four different stages of infection i.e. S0 (pre-inoculatory) stage, S1 stage (7 days after infection), S2 stage (20 days after infection), S3 stage (30 days after infection). The specific activity of superoxide dismutase increased during S0 and S1 and catalase activity was enhanced at later stages of infection. The specific activities of peroxidase, ascorbate peroxidase and glutathione reductase increased with the incidence of disease in resistant genotypes as compared to susceptible genotypes. The timely upregulation and more intensity of defensive enzymes such as SOD, APX-GR followed by CAT and POD in the resistant genotypes as compared to susceptible genotypes might be responsible for resistance to Ascochyta blight. The higher accumulation of H2O2 in resistant genotypes and higher MDA content in susceptible genotypes also contribute to their differential tolerance behaviour towards infection. The upregulation of defensive enzymes at later stages of infection in GLK14313, L552, C. pinnatifidum 212 and their lower activities in ILWC115 might be responsible for their susceptible behaviour indicating that the time and intensity of induced defensive mechanism is an important contributing factor towards disease tolerance.

Examining the effectiveness of biomass-derived biochar for the amelioration of tropospheric ozone-induced phytotoxicity in the Indian wheat cultivar HD 2967

A pot study was performed to evaluate the influence of O3 stress with different biochar treatments on a wheat cultivar (HD 2967). Plants were subjected to ambient and elevated (ambient+20 ppb) O3 along with three doses of biochar (0%, 2.5%, and 5%). Elevated ozone alone reduced most of the growth parameters, negatively affecting the test cultivar's physiology. Although enzymatic antioxidants were up-regulated by elevated O3, damage to the membrane integrity was evident by higher MDA content in the wheat leaves. Besides, the uptake of nutrients was observed to be reduced under elevated O3 due to the reduced phyto-availability of the soil's nutrients and cation exchange capacity. Such limitation of assimilates and nutrients marked a trade-off between growth and defence, translating to grain yield loss. However, applying biochar as a soil conditioner ameliorated the detrimental effects of O3 with respect to the economic yield of wheat. Biochar alone improved soil properties and nutrient phyto-availability, which translated to better plant growth, stronger physiological capacity, and higher crop productivity. Thus, the study inferred that altered nutrient phyto-availablity and its uptake, likely associated with biochar-induced improved soil properties, relayed stronger plant physiology and antioxidative defence system to combat O3 induced oxidative stress.

Calcium affects glucoraphanin metabolism in broccoli sprouts under ZnSO4 stress

CaCl2, Ca2+ chelator (EGTA) and Ca2+ channel blocker (verapamil) were used to investigate mechanism of glucoraphanin metabolism in broccoli sprouts under ZnSO4 stress. CaCl2 treatment promoted sprout growth, reduced MDA (malonaldehyde) content and electrolyte leakage in sprouts under ZnSO4 stress. The highest MDA content and electrolyte leakage were obtained in ZnSO4 plus verapamil-treated sprouts. In addition, ZnSO4 plus CaCl2 treatment significantly enhanced glucoraphanin content and sulforaphane formation, while an opposite result was observed after ZnSO4 plus EGTA treatment; which were further supported by expression of glucoraphanin biosynthetic and hydrolytic genes as well as myrosinase (MYR) and epithiospecifier protein (ESP) activities. These results indicated that exogenous and endogenous calcium promoted glucoraphanin biosynthesis and the conversion rate of glucoraphanin into sulforaphane. Verapamil treatment also stimulated glucoraphanin biosynthesis, but exerted an adverse influence on sulforaphane formation from the hydrolysis of glucoraphanin because of much higher ESP expression and ESP activity than ZnSO4 treatment.

Physiological and biochemical changes in wheat cultivars under salt stress as affected by foliar boron application

In this study, interactive effects of salt stress (150 mM NaCl) and foliar boron (H3BO3; 30 µM) application was studied in two wheat (Triticum aestivum L.) genotypes (Momtchil and Pamukova-97). Chlorophyll a and total chlorophyll content in Momtchil were not affected by salinity, foliar boron and salinity+foliar boron application while chlorophyll b content was increased by foliar boron and salinity+foliar boron application as compared to relative controls, probably due to higher total carotenoid and free proline level. In Pamukova-97, however, foliar boron and salinity+foliar boron application led to the reduced photosynthetic pigment content because of the absence of such a protective mechanism. Antioxidant enzymes of ascorbate-glutathione cycle and superoxide dismutase was not induced by all applications and both remarkable H2O2 accumulation and membrane damage was determined in the leaves of wheat cultivars, as demonstrated by higher MDA content in leaves. As a result, it may be concluded that expected ameliorative effect of foliar boron application did not occur in salt-affected wheat cultivars used in this study.

Genome-Wide Identification of the Physic Nut WUSCHEL-Related Homeobox Gene Family and Functional Analysis of the Abiotic Stress Responsive Gene JcWOX5.

Plant-specific WOX transcription factors have important regulatory functions in plant development and response to abiotic stress. However, the identification and functional analysis of members of the WOX family have rarely been reported in the physic nut plant until now. Our research identified 12 WOX genes (JcWOXs) in physic nut, and these genes were divided into three groups corresponding to the ancient clade, WUS clade, and intermediate clade. Expression analysis based on RNA-seq and qRT-PCR showed that most of the JcWOX genes were expressed in at least one of the tissues tested, whereas five genes were identified as being highly responsive to drought and salt stresses. Subcellular localization analysis in Arabidopsis protoplast cells showed that JcWOX5 encoded a nuclear-localized protein. JcWOX5-overexpression plants increased sensitivity to drought stress, and transgenic plants suggested a lower proline content and CAT activity, higher relative electrolyte leakage, higher MDA content, and higher rate of water loss under drought conditions. Expression of some stress-related genes was obviously lower in the transformed rice lines as compared to their expression in wild-type rice lines under drought stress. Further data on JcWOX5-overexpressing plants reducing drought tolerance verified the potential role of JcWOX genes in responsive to abiotic stress. Collectively, the study provides a foundation for further functional analysis of JcWOX genes and the improvement of physic nut crops.

The NAC transcription factor CaNAC064 is a regulator of cold stress tolerance in peppers

NAC (NAM, ATAF1/2 and CUC2) proteins are plant-specific transcription factors (TFs) that are important in plant abiotic stress responses. In this study we isolated a NAC gene from Capsicum annuum leaves, designated as CaNAC064. We characterized the amino acid sequence of CaNAC064 and found that it contain conserved domains of the NAC family, including a highly conserved N-terminus domain and a highly variable C-terminus domain. Expression analysis showed that the 40C, 400C, salicylic acid (SA) and abscisic acid (ABA) treatments strongly induced the expression of CaNAC064 through silencing of CaNAC064 in pepper and overexpressing in Arabidopsis. CaNAC064-silenced pepper plants exhibited more serious wilting, higher MDA contents and chilling injury index, lower proline content, and more accumulation of ROS in the leaves after cold stress. The CaNAC064-overexpressing Arabidopsis plants exhibited lower MDA content, chilling injury index and relative electrolyte leakage content as compared to WT plants under cold stress. Transcriptional activation activity analysis indicated that CaNAC064 has transcriptional activation activity in the 691–1071 bp key region. We identified 45 proteins that putatively interact with CaNAC064 using the Yeast Two-Hybrid method. According to the Yeast Two-Hybrid and BIFC results, CaNAC064 interacted with low temperature-induced haplo-proteinase proteins in plant cell. These results suggested that CaNAC064 positively modulates plant cold-tolerance, laying the foundation for future investigations into the role of NACs as regulatory proteins of cold tolerance in plants.

High dietary lipid level alters the growth, hepatic metabolism enzyme, and anti-oxidative capacity in juvenile largemouth bass Micropterus salmoides.

The present study was conducted to investigate the effects of high dietary lipid levels on growth, metabolism, antioxidant capacity, and immune responses of largemouth bass. Fish (initial body weight 13.38 ± 0.11g) were fed three isonitrogenous semi-purified diets containing 5%, 10%, and 20% lipid, respectively. The results indicated that fish fed 10% lipid diet showed significantly better final body weight, specific growth rate (SGR), protein efficiency ratio (PER), and feed conversion ratio (FCR) compared with that fed 5% lipid diet. Meanwhile, fish fed 20% lipid diet had a significantly higher viscera ratio (VR), hepatosomatic index (HSI), intraperitoneal fat ratio (IPF), and liver lipid content than those fed the other diets. Higher alanine aminotransferase (ALT) and aspartate transaminase (AST) activities, total cholesterol (TC), triglyceride (TG), free fatty acids (FFA), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) contents, and LDL-C/HDL-C value in plasma were recorded in fish fed 20% lipid diet, while higher insulin contents were obtained in fish fed 5% lipid diet. In addition, the highest carnitine palmitoyltransferase I (CPT1), AMP-activated protein kinase (AMPK), fructose-1,6-bisphosphatase (FBPase), and phosphoenolpyruvate carboxykinase (PEPCK) activities in the liver were also observed in fish fed 20% lipid diet. However, fish fed 20% lipid diet had a significantly lower superoxide dismutase (SOD) and catalase (CAT) activities and higher MDA contents in liver than those fed the other diets. The higher nitric oxide (NO) contents and inducible nitric oxide synthase (iNOS) activity in liver were recorded in fish fed 10% lipid diet. Moreover, the alkaline phosphatase (ALP), inducible nitric oxide synthase (iNOS) and lysozyme activities, and nitric oxide (NO) contents in plasma were higher in fish fed the 10% diets than the other groups. In conclusion, high dietary lipid levels could suppress growth performance and liver anti-oxidative capacity, and reduce immune responses of largemouth bass.