SA Treatment Research Articles

Glutathione Transferases are Involved in Salicylic Acid-Induced Transcriptional Reprogramming

Salicylic acid (SA) plays a crucial role not only in defence against pathogen attacks, but also in abiotic stress responses. Recently, some key steps of SA signalling outlined the importance of redox state-dependent processes. This study explores the role of glutathione transferases (GSTs) in the transcriptional reprogramming of redox status-related genes in seven-day-old wild type and Atgst mutant Arabidopsis thaliana plants. The timing of redox changes, detected by the redox-sensitive green fluorescent protein (roGFP2), differed in wild type roots treated with 10 μM or 100 μM SA. Our results verified how the applied SA concentrations had different effect on the expression of oxidative stress- and redox-related genes, among them on the expression of AtGSTF8 and AtGSTU19 genes. Lower vitality and less negative EGSH values were specific characteristics of the Atgst mutants compared to the wild type plants throughout the experiment. Changes in the redox potential were only modest in the mutants after SA treatments. A slightly modified gene expression pattern was observed in control conditions and after 1 h of SA treatments in Atgst mutants compared to Col-0 roots. These data originating from the whole roots provide indirect evidence for the role of the investigated AtGSTF8 and AtGSTU19 isoenzymes in the transduction of the redox signal. Our results demonstrate that the investigated Arabidopsis GSTs have a role in maintaining the levels of reactive oxygen species- and redox homeostasis and are involved in transcriptional reprogramming in the roots.

Genome-wide identification of the TGA genes in common bean (Phaseolus vulgaris) and revealing their functions in response to Fusarium oxysporum f. sp. phaseoli infection.

Fusarium wilt, which affects common bean all across the world, is caused by Fusarium oxysporum f. sp. Phaseoli (Fop). It is necessary to have functional genes in response to Fop infection because they might be used to manage disease. As a crucial regulator, TGA-binding transcription factor (TGA) is engaged in the defense mechanism of plants against pathogens. The role of TGA regulators in common bean in response to Fop infection, however, has not been documented. Hence, we performed genome-wide identified and characterized eight TGA genes in common bean. In this study, eight PvTGA genes were distributed on six chromosomes and classified into four subgroups. The PvTGA genes have the same conserved bZIP and DOG1 domains, but there are specific sequence structures in different PvTGAs. Phylogenetic and synteny analysis explained that PvTGA gene has a close genetic relationship with legume TGAs and that PvTGA03 and PvTGA05 may play an important role in evolution. Transcriptome data explained that expression levels of PvTGA genes showed diversity in different tissues. After Fop inoculation, the expression levels of PvTGA03 and PvTGA07 were significantly different between resistant and susceptible genotypes. Under SA treatment, the expression levels of PvTGA03, PvTGA04, PvTGA06, PvTGA07 and PvTGA08 were significantly different. These results imply that PvTGA03 and PvTGA07 play key roles in SA-mediated resistance to Fusarium wilt. Together, these findings advance knowledge of the PvTGA gene family in common bean and will help future studies aimed at reducing Fusarium wilt.

Validation of suitable reference genes by various algorithms for gene expression analysis in Isodon rubescens under different abiotic stresses

Isodon rubescens (Hemsley) H. Hara (Lamiaceae) is a traditional Chinese medicine plant that has been used to treat various human diseases. Oridonin is one of the main active ingredients, and the route of its molecular biosynthesis remains to be determined. The study of gene expression patterns can provide clues toward the understanding of its biological functions. The selection of suitable reference genes for normalizing target gene expression is the first steps in any quantitative real-time PCR (RT-qPCR) gene expression study. Therefore, validation of suitable reference genes is necessary for obtaining reliable results in RT-qPCR analyses of I. rubescens. Here, 12 candidate reference genes were chosen, and their expression stability in different tissues of I. rubescens and in leaves under different abiotic stresses (NaCl, dehydration, SA, MeJA, and ABA) was evaluated using the ∆Ct, NormFinder, GeNorm, BestKeeper, and RankAggreg statistical tools. Analysis using the comprehensive tools of RankAggreg algorithm showed that GADPH, 18S and eIF were stably expressed in different tissues; UBQ, Apt, and HIS; Cycl, UBQ, and PP2A; GADPH, 18S, and eIF; eIF, UBQ, and PP2A; TUB, Cycl, and UBQ; were the best three candidate reference genes for the samples of Dehydration, NaCl, SA, MeJA, and ABA treatment, respectively. While for the concatenated sets of ND (NaCl and dehydration) and SMA (SA, MeJA, and ABA), UBQ, HIS, and TUA; UBQ, eIF and Apt were the three appropriate candidate reference genes, respectively. In addition, the expression patterns of HMGR in different tissues and under different treatments were used to confirm the reliability of the selected reference genes, indicating that the use of an inappropriate reference gene as the internal control will cause results with a large deviation. This work is the first study on the expression stability of reference genes in I. rubescens and will be particularly useful for gene functional research in this species.

Abscisic Acid, Paclobutrazol, and Salicylic Acid Alleviate Salt Stress in Populus talassica × Populus euphratica by Modulating Plant Root Architecture, Photosynthesis, and the Antioxidant Defense System

The exogenous plant growth regulators (PGRs) represent a useful strategy for reducing the adverse effects of salt stress in plants. In order to investigate the regulatory effect of exogenous PGRs on the salt tolerance of Populus talassica × Populus euphratica seedlings, in this study, the effects of different foliar spray concentrations of ABA (5 mg·L−1, 15 mg·L−1, 25 mg·L−1), PP333 (300 mg·L−1, 900 mg·L−1, 1500 mg·L−1), and SA (40 mg·L−1, 120 mg·L−1, 200 mg·L−1) on P. talassica × P. euphratica seedlings under salt stress (soil salt concentration of 2%) were determined. The results showed that the dry weight, total root length, root surface area, root volume, total Chl content, and photosynthetic parameters of P. talassica × P. euphratica seedlings significantly decreased under salt stress and increased their contents of malondialdehyde (MDA), hydrogen peroxide (H2O2), superoxide anion (O2−), free proline (Pro), superoxide dismutase (SOD), and peroxidase (POD). However, ABA, PP333, and SA can mitigate the adverse effects of salt stress on these indicators. Especially, the 15 mg·L−1 ABA, 900 mg·L−1 PP333, and 120 mg·L−1 SA treatments had the best effect on alleviating salt stress, with significant increases in dry weight, root parameters, total Chl content, and the photosynthetic parameters of the P. talassica × P. euphratica seedlings, improving their photosynthetic characteristics; meanwhile, increased Pro content and enzyme activity and decreased MDA, H2O2, and O2− content protected the integrity of membrane system and enhanced the salt tolerance of the seedlings. SA resulted in a better ameliorative effect on salt stress compared to ABA and PP333.

Effects of Different Soil Moisture-Holding Strategies on Growth Characteristics, Yield and Quality of Winter-Seeded Spring Wheat

Drought during the overwintering period threatens the emergence rate and restricts the yield under the “winter-seeded spring wheat” cultivated model in the Hetao Plain Irrigation District in Inner Mongolia. To address this issue, from 2017 to 2019, six treatments were set up in the field to study the emergence rate, growth attributes, grain quality, yield and its percentage of winter-seeded spring wheat. These treatments were the (1) application of water-retaining agents under winter sowing (WRA), (2) soil amendments under winter sowing (SA) and wheat seed presoaking with amino acid water-soluble fertilizer under winter sowing (SP), (3) straw mulching under winter sowing (SM), (4) film-mulching hole sowing under winter sowing (FMHS), (5) blank control under winter sowing (CKW) and (6) conventional blank control under spring sowing (CKS). The results showed that the emergence rate of winter-seeded treatment was lower than CKS treatment, the emergence of WRA, SA, SM, and FMHS treatment increased by 5.4%, 2.3%, 6.5% and 10.8% compared with CKW treatment, respectively. The winter-seeded treatment is earlier than CKS treatment in the growth process, in which FMHS treatment is between 12 d and 16 d earlier in the emergence period, between 13 d and 15 d earlier in the maturation period, between 8 d and 12 d earlier than the CKW treatment in the emergence period, and between 8 d and 10 d earlier in the maturity period. Compared with CKW treatment, WRA, SA, SM, FMHS and CKS treatments increased yield by 13.49%, 11.42%, 14.75%, 21.61% and 28.15%, respectively. FMHS treatment significantly reduced the total water consumption and significantly improved water use efficiency. The protein content, wet gluten content, sedimentation value, dough ductility and maximum resistance in CKS treatment were significantly lower than other winter sowing treatments. The protein percentage and wet gluten percentage in FMHS treatment were the highest, and the difference with CKW treatment was significant. In summary, film-mulching hole sowing in winter improves soil water and the emergence rate, significantly accelerates the growth process of wheat, increases yield and promotes grain quality.

Synergistic and antagonistic effects of preharvest salicylic acid and postharvest 1-methylcyclopropene treatments on the storage quality of apricot

Preharvest salicylic acid (SA, 1 mmol/L) spraying at 72 and 74 days after complete bloom combined with postharvest 1-methylcyclopropene (1-MCP, 1 μL L-1) fumigation was conducted to improve the storage quality of apricot. The results showed that preharvest SA combined with postharvest 1-MCP (SA + 1-MCP) treatment delayed the ethylene peak, inhibited respiration, slowed fruit softening, maintained high sugar and organic acid contents, and maintained high antioxidant capacity in apricots. SA + 1-MCP treatment produced synergistic effects on ethylene production, respiration rate, firmness, sorbitol, glucose and citric acid, but antagonistic effects on fructose, sucrose, malic acid, and total phenolic content and antioxidant capacity. In addition, SA treatment could overcome the disadvantages or enhance positive effects of 1-MCP treatment. Both synergistic and antagonistic effects of SA + 1-MCP treatment can achieve efficient preservation than individual 1-MCP or SA treatment. Thus, the SA + 1-MCP treatment may be an effective method for improving the storage quality of apricots.

Effect of Salicylic Acid and Pre-Cold Treatment on Flower Induction in Saffron.

Saffron is an important flowering plant, generally known as a golden condiment. The present study was performed to find the influence of different levels of SA and pre-cold treatment in the dormancy period of saffron and their effects on content enzyme activity. The results indicated that the SA2%, SA1%, and, pre-cold treatments took the shortest day to flowering. PAL enzyme activity was highest in pre-cold treatment. The higher total amount of protein was measured in the control, SA1% and SA2%. The highest amount of starch content and total soluble sugar was detected in pre-cold, SA2%, and control, respectively. No significant differences between treatments were present for CAT, PPO, GPX, and APX enzymes activity. There was a negative significant correlation between flowering time and some studied traits, i.e., starch and PAL activity. Applying SA and pre-cold treatment can induce saffron flowering and effect on pal enzyme activity and corm total protein, sugar, and starch content accordingly.

Cloning, Subcellular Location and Expression Analysis of Grape Myb Gene

MYB gene plays an important role in plant growth, development and response to abiotic stress. In the present study, ‘Yatomi Rosa’ grape (Vitis vinifera L.) was used as the test material. Two MYB, VvMYBB1 and VvMYBA3 gene were obtained by homologous cloning, and their subcellular location, different organs, and expression patterns under stress treatment and hormone induction were obtained. VvMYBB1 and VvMYBA3 proteins were located in the nucleus and belonged to nuclear proteins. They were highly expressed in roots and flowers. These genes might have a negative effect on the formation of peel color. VvMYB1 gene and VvMYBA3 gene might play an important role in drought resistance and salt stress resistance. Under the induction of exogenous hormones, relative expression of VvMYBB1 gene was higher than that of VvMYBA3 gene under IAA, ETH, SA and MeJA treatment. Relative expression of VvMYBB1 gene was lower than that of VvMYBA3 gene under 6-BA, GA3 and ABA treatment. It showed that MYB gene played an important role in the development of different organs of grapes, fruit color, and response to abiotic stress and exogenous hormones induction in grape. Bangladesh J. Bot. 51(3): 499-506, 2022 (September)

Identification and expression analysis of the grape pentatricopeptide repeat (PPR) gene family in abiotic stress.

The pentatricopeptide repeat (PPR) is one of the largest gene family in plants, and play important role in regulating plant growth, development and abiotic stress response. However, PPR genes have been poorly studied in grapes. In this study, based on the grape genome database, bioinformatics methods and quantitative real-time PCR (qRT-PCR) were used to identify the VvPPR family and the response to abiotic stress. A total of 181 PPR genes were identified in grape and divided into two subfamilies. Subcellular localization predicted that this gene family mainly functions in chloroplasts, nucleus, and mitochondria. Protein-protein interaction prediction indicated that there may be interaction between VvPPR44,53 and VvPPR44. The promoter region of VvPPR gene family contained various cis-acting elements, which were related to light and hormone. Expression pattern analysis showed that the VvPPR gene family was highly expressed in grape leaves, buds and carpel tissues. qRT-PCR results showed that the expression of VvPPR genes in roots was higher than stems and leaves under NAA, SA, ABA, MeJA and GA3 treatments. VvPPR8 was significantly up-regulated after GA3 and MeJA treatment for 24h, VvPPR53 was significantly up-regulated after SA, NAA, ABA and MeJA treatment. In addition, In grape leaves, VvPPR53 was up-regulated under PEG, Nacl and 4℃ treatments. These data indicate that VvPPR gene family members are responsive to hormones and abiotic stresses, and that there are some differences in the degree of response and expression in different grape tissues. This study provides a certain theoretical basis for grape resistance breeding.

Blue light combined with salicylic acid treatment maintained the postharvest quality of strawberry fruit during refrigerated storage.

Strawberryis a high economic and nutritional valuefruit,but marketing is limited by a short postharvest life. The objective of this work is to assess the influence of blue light (BL) and salicylic acid (SA, 2mM) on strawberry postharvest quality during cold storage. The results showed that the combination of BL and SA noticeably delayed weight loss, prevented decay, improved fruit skin brightness, and increased soluble protein. Strawberries treated with BL+SA had lower total soluble solids and titratable acidity contents among treatments but had no significant change during the entire storage. Additionally, contents of total flavonoids, phenolics, anthocyanins and proanthocyanidins, activities of superoxide dismutase (SOD) and ascorbate peroxidase (APX) and total antioxidant capacities in BL+SA-treated fruit were kept at stable levels throughout the entire storage. Collectively, these findings suggest that BL+SA treatment exhibits a high potential in maintaining postharvest fruit quality of strawberry fruit.

Identification and Analysis of JAZ Gene Family in Ginkgo biloba Reveals Candidate Genes for Biosynthesis of Terpene Trilactones

Terpene trilactones (TTLs) are the main secondary metabolites in Ginkgo biloba L. with efficacious pharmacological activity. Jasmonate ZIM-domain (JAZ) protein is a key regulatory factor of the JA signaling pathway, which regulates the biosynthesis of secondary metabolites such as terpenes, alkaloids, and flavonoids. In this study, GbJAZ01~GbJAZ11 were identified from the genome data in G. biloba, which contained TIFY-, Jas-, and weakly conserved NT-domains, and the promoters in most of them contained light, hormone, and stress-responsive elements. Phylogenetic analysis divided all JAZ proteins of Arabidopsis thaliana, Oryza sativa, Picea sitchensis, Taxus chinensis, and G. biloba into nine groups, in which GbJAZs belong to Group VI-IX. GbJAZs have similar functional motifs to A. thaliana and O. sativa, but also contain three specific motifs of gymnosperms, indicating that, although gymnosperms and angiosperms have some conservative structures and functions, their evolutionary processes are independent. Expression pattern analysis showed that the expression levels of GbJAZs were significantly up-regulated by MeJA, but the change pattern and amplitude were different, indicating that the function of GbJAZs in response to a JA signal may be different. After ABA and SA treatment, the expression of GbJAZs was up-regulated or inhibited in varying degrees, and different GbJAZs may be involved in the synergistic or antagonistic effects between JA and other hormone signals. The MeJA significantly increased the content of TTLs in G. biloba leaves, which were significantly positively correlated with the expression levels of GbJAZ01, 02, 07, and 11, and negatively correlated with the expression of GbJAZ04. They may play an important role in JA signaling pathways and the interactions between JA and other hormone signals, and participate in the regulation of the biosynthesis of TTLs. Our results provide a reference for the discovery that GbJAZs are involved in JA signaling pathways, and lay a theoretical foundation for analyzing JA signaling pathways to regulate the synthesis of secondary metabolites.

Genome-Wide Characterization of the Methyl CpG Binding Domain-Containing Proteins in Watermelon and Functional Analysis of Their Roles in Disease Resistance Through Ectopic Overexpression in Arabidopsis thaliana.

Methyl-CPG-Binding Domain (MBD) proteins play important roles in plant growth, development, and stress responses. The present study characterized the MBD families in watermelon and other cucurbit plants regarding the gene numbers and structures, phylogenetic and syntenic relationships, evolution events, and conserved domain organization of the MBD proteins. The watermelon ClMBD proteins were found to be localized in nucleus, and ClMBD2 and ClMBD3 interacted with ClIDM2 and ClIDM3. ClMBD2 bound to DNA harboring methylated CG sites but not to DNA with methylated CHG and CHH sites in vitro. The ClMBD genes exhibited distinct expression patterns in watermelon plants after SA and MeJA treatment and after infection by fungal pathogens Fusarium oxysporum f.sp. niveum and Didymella bryoniae. Overexpression of ClMBD2, ClMBD3, or ClMBD5 in Arabidopsis resulted in attenuated resistance against Botrytis cinerea, accompanied by down-regulated expression of AtPDF1.2 and increased accumulation of H2O2 upon B. cinerea infection. Overexpression of ClMBD1 and ClMBD2 led to down-regulated expression of AtPR1 and decreased resistance while overexpression of ClMBD5 resulted in up-regulated expression of AtPR1 and increased resistance against Pseudomonas syringae pv. tomato DC3000. Transcriptome analysis revealed that overexpression of ClMBD2 in Arabidopsis up-regulated the expression of a small set of genes that negatively regulate Arabidopsis immunity. These data suggest the importance of some ClMBD genes in plant immunity and provide the possibility to improve plant immunity through modification of specific ClMBD genes.

Non-Coding RNAs Regulate Spontaneous Abortion: A Global Network and System Perspective.

Spontaneous abortion is a common pregnancy complication that negatively impacts women’s health and commercial pig production. It has been demonstrated that non-coding RNA (ncRNA) is involved in SA by affecting cell proliferation, invasion, apoptosis, epithelial-mesenchymal transformation (EMT), migration, and immune response. Over the last decade, research on ncRNAs in SA has primarily concentrated on micro RNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs). In this review, we discuss recent ncRNA studies focused on the function and mechanism of miRNAs, lncRNAs, and circRNAs in regulating SA. Meanwhile, we suggest that a ceRNA regulatory network exists in the onset and development of SA. A deeper understanding of this network will accelerate the process of the quest for potential RNA markers for SA diagnosis and treatment.

Effects of therapeutic levels of dietary antibiotics on the cecal microbiome composition of broiler chickens

Dietary antibiotics, including antibiotic growth promoters (AGPs), have been commonly used to improve health and growth of poultry. The present study investigated the effects of therapeutic doses of dietary antibiotics, including bacitracin methylene disalicylate (BMD), penicillin G potassium (PP) and an ionophore (salinomycin, SA), on the cecal microbiome of chickens. BMD and SA treatments were given as dietary supplements from d 1 to 35 of age. The SAPP (salinomycin+ penicillin G potassium) group was given SA as a dietary supplement from d 1 to 35 of age and PP was added to drinking water from d 19 to 24 of age to simulate common practices for control of necrotic enteritis in broilers. The cecal contents were collected from all treatment groups on d 10, 24, and 35 of age and DNA was extracted for metagenomic analysis of the cecal microbiome. The results revealed that dietary or water supplementation of therapeutic levels of antibiotics and ionophores to chickens significantly altered the cecal microbial homeostasis during different stages of the chicken life. The alpha diversity analysis showed that BMD, SA, and SAPP treatments decreased diversity and evenness of the cecal microbiome of treated chickens on d 10 of age. Species richness was also reduced on d 35 following treatment with BMD. Beta diversity analyses revealed that SAPP and BMD induced significant changes in the relative abundance of Gram-positive and -negative bacteria on d 10, while no significant differences were observed on d 24. On d 35, the non-treated control group had higher relative abundance of unclassified Gram-positive and -negative bacteria compared to SA, SAPP, and BMD treatment groups. Overall, despite their beneficial role in controlling necrotic enteritis outbreaks, the findings of this study highlight the potential negative effects of dietary supplementation of therapeutic levels of antibiotics on the gut microbiome and suggest that adjusting gut bacteria may be required to restore microbial richness and diversity of the gut microbiome following treatment with these antibiotics.

Expression of ZjPSY, a Phytoene Synthase Gene from Zoysia japonica Affects Plant Height and Photosynthetic Pigment Contents.

Phytoene synthase (PSY) is a key limiting enzyme in the carotenoid biosynthesis pathway for regulating phytoene synthesis. In this study, ZjPSY was isolated and identified from Zoysia japonica, an important lawn grass species. ZjPSY cDNA was 1230 bp in length, corresponding to 409 amino acids. ZjPSY showed higher expression in young leaves and was downregulated after GA3, ABA, SA, and MeJA treatments, exhibiting a sensitivity to plant hormones. Regulatory elements of light and plant hormone were found in the upstream of ZjPSY CDS. Expression of ZjPSY in Arabidopsis thaliana protein led to carotenoid accumulation and altered expression of genes involved in the carotenoid pathway. Under no-treatment condition, salt treatment, and drought treatment, transgenic plants exhibited yellowing, dwarfing phenotypes. The carotenoid content of transgenic plants was significantly higher than that of wild-type under salt stress and no-treatment condition. Yeast two-hybrid screening identified a novel interacting partner ZjJ2 (DNAJ homologue 2), which encodes heat-shock protein 40 (HSP40). Taken together, this study suggested that ZjPSY may affect plant height and play an important role in carotenoid synthesis. These results broadened the understanding of carotenoid synthesis pathways and laid a foundation for the exploration and utilization of the PSY gene.

Exogenous Application of Salicylic Acid and Hydrogen Peroxide Ameliorate Cadmium Stress in Milk Thistle by Enhancing Morpho-Physiological Attributes Grown at Two Different Altitudes.

Cadmium (Cd+2) is a potential and widespread toxic environmental pollutant, mainly derived from a rapid industrial process that has inhibitory effects on growth, physiological, and biochemical attributes of various plant species, including medicinal plants such as Silybum marianum L. Gaertn commonly known as milk thistle. Plant signaling molecules, when applied exogenously, help to enhance/activate endogenous biosynthesis of potentially important signaling molecules and antioxidants that boost tolerance against various abiotic stresses, e.g., heavy metal stress. The present study documented the protective role of salicylic acid (SA;0.25 μM) and hydrogen peroxide (H2O2; 10 μM) priming, foliar spray, and combinational treatments in reducing Cd+2 toxicity (500 μM) in milk thistle grown at two diverse ecological zones of Balochistan Province of Pakistan i.e., Quetta (Qta) and Turbat (Tbt). The morpho-physiological and biochemical attributes of milk thistle were significantly affected by Cd+2 toxicity; however, priming and foliar spray of SA and H2O2 significantly improved the growth attributes (root/shoot length, leaf area, and root/shoot fresh and dry weight), photosynthetic pigments (Chl a, b, and carotenoids) and secondary metabolites (Anthocyanin, Soluble phenolics, and Tannins) at both altitudes by suppressing the negative impact of Cd+2. However, the oxidative damage parameters, i.e., MDA and H2O2, decreased astonishingly under the treatment of signaling molecules, thereby protecting membrane integrity under Cd+2 stress. The morphological variations were profound at the low altitude (Tbt) as compared to the high altitude (Qta). Interestingly, the physiological and biochemical attributes at both altitudes improved under SA and H2O2 treatments, thus hampered the toxic effect of Cd+2. These signaling compounds enhanced tolerance of plants under heavy metal stress conditions with the consideration of altitudinal, and ambient temperature variations remain to be the key concerns.

Salicylic acid mitigates salt induced toxicity through the modifications of biochemical attributes and some key antioxidants in capsicum annuum

Abiotic stress causes extensive loss to agricultural yield production worldwide. Salt stress is one of them crucial factor which leads to decreased the agricultural production through detrimental effect on growth and development of crops. In our study, we examined the effect of a defense growth substance, salicylic acid (SA 1 mM) on mature vegetative (60 Days after sowing) and flowering (80 DAS) stage of Pusa Sadabahar (PS) variety ofCapsicum annuum L. plants gown under different concentrations of NaCl (25, 50, 75, 100 and 150 mM) and maintained in identical sets in pots during the whole experiment. Physiological studies indicated that increase in root & shoot length, fresh & dry weight, number of branches per plant, and yield (number of fruits per plant) under salt + SA treatment. Biochemical studies, enzymatic antioxidants like CAT, POX, and non-enzymatic antioxidant such as ascorbic acid (AsA content), carotenoids, phenolics, besides other defense compounds like proline, protein, chlorophyll contents were studied at 10 days after treatment at the mature vegetative and flowering stage. The addition of SA led to lowering of in general, all studied parameters in the mature vegetative stage but increased the same during the flowering stage, especially in the presence of NaCl; although the control I (without SA and NaCl) remained lower in value than control II (with SA, without NaCl). Interestingly, total phenolics were higher in control I (without SA or NaCl) whereas chlorophylls were higher in treatments with SA and NaCl. Thus, physiological concentration of SA (1 mM) appears to be significantly effective against salt stress during the flowering stage. In addition, during the mature vegetative stage, however, proline accumulates in SA treated sets, to help in developing NaCl-induced drought stress tolerance.

Molecular Characterization and Activity Analysis of Promoters from Two Cucumber Translationally Controlled Tumor Protein Genes (CsTCTPs)

Aims: The aim of the paper was to isolate and characterize the promoters of two cucumber TCTP genes (CsTCTP1 and CsTCTP2) and evaluate their active domains.
 Study Design: CsTCTP1 and CsTCTP2 promoter activity were analyzed under treatments with different exogenous hormones.
 Place and Duration of Study: In 2017, these experiments were conducted in College of Bioscience and Biotechnology of Shenyang Agricultural University (Lab 240).
 Methodology: CsTCTPpro::GUS constructs were generated by using double digests method. Transient expression was mediated by Agrobacterium tumefaciens GV3101. Histochemical and Fluorometric GUS Assays were follow by the biochemical method.
 Results: Bioinformatics analysis revealed some hormone- and defense-related response elements. Histochemical and fluorometric GUS assays demonstrated that the 0.7-kb CsTCTP1 promoter (proT1-0.7kb) and 0.7-kb and 1.3-kb CsTCTP2 promoters (proT2-0.7kb and proT2-1.3kb) had strong transcriptional activity. In addition, we used exogenous hormones (abscisic acid [ABA], salicylic acid [SA], and ethylene [ETH]) for treatment. The results showed that proT1-0.7kb and proT2-1.3kb activity were upregulated in the ABA treatment group, suggesting that these promoter sequences may contain ABA-related response elements. However, in the SA and ETH treatment groups, the activity of all the promoter fragments of CsTCTP1 and CsTCTP2 declined to different degrees, suggesting that SA and ETH may have negative regulatory effects on CsTCTP1 and CsTCTP2 promoters.
 Conclusion: Taken together, these results suggest that the proT1-0.7kb promoter of CsTCTP1 and proT2-1.3kb promoter of CsTCTP2 may contain ABA-related response elements, and SA and ETH may have negative regulatory effects on the CsTCTP1 and CsTCTP2 promoters. This study will help to further understand the expression patterns and the regulatory mechanism of gene transcriptional regulation.

Genome-wide characterization of bZIP gene family identifies potential members involved in flavonoids biosynthesis in Ginkgo biloba L.

Ginkgo biloba L. is an ancient relict plant with rich pharmacological activity and nutritional value, and its main physiologically active components are flavonoids and terpene lactones. The bZIP gene family is one of the largest gene families in plants and regulates many processes including pathogen defense, secondary metabolism, stress response, seed maturation, and flower development. In this study, genome-wide distribution of the bZIP transcription factors was screened from G. biloba database in silico analysis. A total of 40 bZIP genes were identified in G. biloba and were divided into 10 subclasses. GbbZIP members in the same group share a similar gene structure, number of introns and exons, and motif distribution. Analysis of tissue expression pattern based on transcriptome indicated that GbbZIP08 and GbbZIP15 were most highly expressed in mature leaf. And the expression level of GbbZIP13 was high in all eight tissues. Correlation analysis and phylogenetic tree analysis suggested that GbbZIP08 and GbbZIP15 might be involved in the flavonoid biosynthesis. The transcriptional levels of 20 GbbZIP genes after SA, MeJA, and low temperature treatment were analyzed by qRT-PCR. The expression level of GbbZIP08 was significantly upregulated under 4°C. Protein–protein interaction network analysis indicated that GbbZIP09 might participate in seed germination by interacting with GbbZIP32. Based on transcriptome and degradome data, we found that 32 out of 117 miRNAs were annotated to 17 miRNA families. The results of this study may provide a theoretical foundation for the functional validation of GbbZIP genes in the future.

Nitrate alleviates ammonium toxicity in wheat (Triticum aestivum L.) by regulating tricarboxylic acid cycle and reducing rhizospheric acidification and oxidative damage

ABSTRACT Ammonium (NH4 +) is one of the most important nutrients required by plants. However, a high concentration of NH4 + as the sole nitrogen source suppresses plant growth. Although nitrate (NO3 −) can alleviate NH4 + toxicity, the mechanisms underlying this ability have not been fully elucidated. In this study, wheat plants were cultivated in hydroponic solution with 7.5 mM NO3 − (control), 7.5 mM NH4 + (sole ammonium, SA) or 7.5 mM NH4 + plus 1.0 mM NO3 − (ammonium and nitrate, AN). The results showed that compared with the control, the SA treatment significantly decreased root growth, protein content and the concentrations of most intermediates and the activity of enzymes from the tricarboxylic acid (TCA) cycle. Moreover, increased the activity of plasma membrane H+-ATPase and the rate of H+ efflux along roots, caused solution acidification, and increased the activity of mitochondrial respiratory chain complexes I–IV and the contents of protein-bound carbonyls and malondialdehyde in roots. SA treatment induced ultrastructure disruption and reduced the viability of root cells. Compared with the SA treatment, the AN treatment increased root growth, protein content, the concentrations of most intermediates and the activity of enzymes from the TCA cycle. Furthermore, AN treatment decreased the rate of H+ efflux, retarded medium acidification, decreased protein carbonylation and lipid peroxidation in roots and relieved ultrastructure disruption and increased the viability of root cells. Taken together, these results indicate that NO3 –-dependent alleviation of NH4 + toxicity in wheat seedlings is closely associated with physiological processes that mediate TCA cycle, relieve rhizospheric acidification and decrease the production of ROS and oxidative damage.