Salt stress affects global protein expression profiles of extracellular membrane-derived vesicles of <i>Listeria monocytogenes</i>

Lee, Taewon,Jun, So Hyun,Choi, Chi Won,Kim, Seung Il,Lee, Je Chul,Shin, Ji Hyun Elsevier 2018 Microbial pathogenesis Vol.115 No.-

<P><B>Abstract</B></P> <P>Our previous study has suggested that <I>Listeria monocytogenes</I> produces extracellular membrane vesicles (MVs) and its general stress transcription factor sigma B (σ<SUP>B</SUP>) affects the production of MVs under energy stress. The objective of this study was to evaluate the production of MVs and perform global protein profiling for MVs with or without salt stress to understand the function of MVs in the pathogenesis of <I>L. monocytogenes</I>. When cells of <I>L. monocytogenes</I> were grown under 0.5 M salt stress, protein concentrations of MVs derived from wild-type strain and its isogenic Δ<I>sigB</I> mutant were approximately doubled compared to those of MVs derived from cells without salt stress. Proteomic analyses showed that the number of MV proteins expressed in wild-type strain was similar to that in Δ<I>sigB</I> mutant under salt stress. However, global protein expression profiles were dramatically changed under salt stress compared to those without salt stress. Fifteen σ<SUP>B</SUP> dependent proteins were expressed in MVs of wild-type strain under salt stress, including osmolyte transporter OpuCABCD. In addition, MVs produced by salt stressed wild-type and Δ<I>sigB</I> mutant inhibited biofilm formation abilities of both strains. Taken together, our results suggest that salt stress can promote the production of MVs involved in carnitine transporter proteins, with σ<SUP>B</SUP> playing a pivotal role in biological event.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Osmolyte transpoter proteins are packed in MVs from salt stressed <I>L. monocytogenes.</I> </LI> <LI> OpuCABCD regulated by σ<SUP>B</SUP> are important MV proteins obtained under salt stress. </LI> <LI> MVs obtained from salt stress do not contribute to biofilm forming ability. </LI> </UL> </P>

Alleviation of Salt-induced Deleterious Effects in Chrysanthemum Plant and Soil by Silicon Supplement

Young Shin Chon,Su Hyeon Ha,Kyeong Jin Jeong,Jae Gill Yun 한국화훼학회 2016 화훼연구 Vol.24 No.2

Chrysanthemums (Dendranthema grandiflorum ‘Iwanohakusen’) were grown in a greenhouse with complete nutrient solution system to investigate the effect of silicon (Si) supplement on salt induced deleterious effects in chrysanthemum plants. The experiment was conducted in plastic pots supplemented with a mixture of upland soil : leaf mold : river sand (3:3:4, v:v:v). Si and salinity were treated in combination with two levels of NaCl (0 and 100 mM) and two sources of silicon (K2SiO3, KSi and silicate fertilizer, SiF) at the same concentration (1.8 mM Si) by weekly-drenching for 12 weeks. Chrysanthemum plants supplemented with Si increased in fresh and dry matter enhancing water content and salinity tolerance. The plants grown under salt stress produced less fresh and dry matter than control plant. However, Si supplement to plants under salt stress ameliorated negative effects of salt stress. In soil, EC and NaCl increased by salt stress were mitigated by Si supplement. Salt stress significantly decreased the contents of K and P in leaf, but Si supplement under salt stress significantly recovered the decreased contents with enormous desorption of K and P in soil. Added Si significantly increased content of available SiO2 with its adsorption by salt stress in soil, which was directly related to Si accumulation in leaf. However, Si uptake by roots was suppressed by salt stress irrespective of Si supplement. Si supplement did not ameliorated the negative effects of salt stress on chlorophyll content and membrane integrity in leaf of chrysanthemum plant although significantly increased Si content in leaf, but reversed pest (Liriomyza trifolii) resistance to above-control level.

Transcriptome analysis reveals salt-stress-regulated biological processes and key pathways in roots of peanut (Arachis hypogaea L.)

Shanlin Yu,Na Chen,Maowen Su,Xiaoyuan Chi,Zhimeng Zhang,Lijuan Pan,Mingna Chen,Tong Wang,Mian Wang,Zhen Yang 한국유전학회 2016 Genes & Genomics Vol.38 No.6

The cultivated peanut is important oil crop and salt stress seriously influences its development and yield. Tolerant varieties produced using transgenic techniques can effectively increase peanut plantation area and enhance its yields. However, little is known about how gene expression is regulated by salt stress in peanut. In this study, we screened genes regulated by salt stress in peanut roots using microarray technique. In total, 4828 up-regulated and 3752 down-regulated probe sets were successfully identified in peanut roots subjected to 3 and 48 h of salt stress. Data analysis revealed that different response groups existed between the up and down-regulated probe sets. The main up-regulated biological processes involved in salt stress responses included transcription regulation, stress response, and metabolism and biosynthetic processes. The main down-regulated biological processes included transport processes, photosynthesis and development. The Kyoto encyclopedia of genes and genomes pathway analysis indicated that metabolic pathway, biosynthesis of unsaturated fatty acids and plant–pathogen interaction, were mainly up-regulated in peanut under salt stress. However, photosynthesis and phenylalanine metabolism were mainly down-regulated during salt stress. The function of some probe sets in salt stress regulation was not clarified (e.g., protein functioning in cell cycle regulation and xylem development). Many of the genes we identified lacked functional annotations and their roles in response to salt stress are yet to be elucidated. These results identified some candidate genes as potential markers and showed an overview of the transcription map, which may yield some useful insights into salt-mediated signal transduction pathways in peanut.

Functional deficiency of phytochrome B improves salt tolerance in rice

Kwon, Choon-Tak,Song, Giha,Kim, Suk-Hwan,Han, Jaehyuk,Yoo, Soo-Cheul,An, Gynheung,Kang, Kiyoon,Paek, Nam-Chon Elsevier 2018 Environmental and experimental botany Vol.148 No.-

<P><B>Abstract</B></P> <P>Soil degradation affects agriculture worldwide. Soils with high salt can result from local geological conditions or accumulation of salt from irrigation. Salt limits water uptake and reduces crop yields; therefore, salt tolerance is an important trait for crops grown in high-salt soils. Here, we show that the rice (<I>Oryza sativa</I>) <I>phytochrome B</I> (<I>osphyB</I>) mutant has greater tolerance to salt stress than its parent <I>japonica</I> rice (cv. Dongjin). We found that the <I>osphyB</I> mutant showed a higher survival rate, fresh weight, and levels of total chlorophylls and carotenoids, as well as enhanced membrane integrity under salt stress compared to the wild type. <I>OsPHYB</I> transcripts increased in tissues of the wild type after salt treatment; <I>OsPHYB</I> expression was much higher in the leaf blade than in the stem and root. The <I>osphyB</I> mutant accumulated less Na<SUP>+</SUP> in the shoot and considerably more K<SUP>+</SUP> in both the shoot and root, maintaining a significantly lower Na<SUP>+</SUP> to K<SUP>+</SUP> ratio, possibly due to a lower rate of Na<SUP>+</SUP> uptake and a higher rate of K<SUP>+</SUP> uptake. To elucidate the possible mechanism of salt tolerance in the <I>osphyB</I> mutant, we performed quantitative reverse transcription PCR analysis, which indicated that salt stress-associated genes, including transcription factors and high-affinity K<SUP>+</SUP> transporters, are upregulated in the <I>osphyB</I> mutant under high-salinity conditions. Taken together, our findings show that the null mutation of <I>OsPHYB</I> contributes to a decrease in the Na<SUP>+</SUP>/K<SUP>+</SUP> ratio and enhances cell membrane integrity through upregulation of salt stress-associated genes, resulting in improved tolerance to salt stress.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The rice <I>osphyB</I> mutation confers enhanced tolerance to salt stress. </LI> <LI> <I>OsphyB</I> mutants show altered expression of salinity stress-associated genes. </LI> <LI> Altered expression of K<SUP>+</SUP> transporters decreases the Na<SUP>+</SUP>/K<SUP>+</SUP> ratio in <I>osphyB</I> mutants. </LI> <LI> Improved reactive oxygen species scavenging mitigates oxidative stress in <I>osphyB</I>. </LI> </UL> </P>

Enhanced Fatty Acid Productivity by Parachlorella sp., a Freshwater Microalga, via Adaptive Laboratory Evolution Under Salt Stress

김지훈,김광민,박한울,이창수,남승원,임경준,정지영,홍성주,이철균 한국생물공학회 2021 Biotechnology and Bioprocess Engineering Vol.26 No.2

Salt stress can be used to increase intracellular lipid content of microalgae. However, the growth of microalgae is decreased under salt stress. Thus, a two-stage cultivation strategy with a growth phase followed by a stress stage is required to improve lipid content. In this study, adaptive laboratory evolution (ALE) with salt stress was conducted to improve biomass and fatty acid (FA) productivity using a locally isolated freshwater microalga Parachlorella sp. in a single-stage cultivation. Algal cell growth and FA production under conditions of salt stress (0 - 40 g of NaCl/L) were compared to those in a 0.5 L bubble column photobioreactor and appropriate levels of salt stress (10 and 20 g/L) were determined for ALE. During the ALE process, the average cell size increased from 3.0 to 3.9 μm. After eight consecutive ALE cycles, microalgal growth rate was remarkably increased to close to that of the culture without salt stress. Furthermore, FA content in microalga was improved from 7.5% to 25%. This result was confirmed by observations with various types of microscopes. Eventually, overall FA productivity was increased up to 219.0 ± 10.7 mg/L/day with the addition of 20 g of NaCl/L, which was 233% greater than that of the culture without salt stress (93.8 ± 5.3 mg/L/day) due to increased FA content. Recovered biomass productivity was 80% of that in the culture without salt stress. These results suggest that microalgal FA production can be significantly improved by a simple ALE process without an additional stress culture step.

A Salt Stress-activated Mitogen-activated Protein Kinase in Soybean Is Regulated by Phosphatidic Acid in Early Stages of the Stress Response

임종희,이형석,Jitae Kim,Ho Bang Kim,Kim Seyoung,김병문,안정선 한국식물학회 2012 Journal of Plant Biology Vol.55 No.4

Salt stress inhibits plant growth and development and plants activate kinase-dependent survival pathways in response to salt stress. However, the role of soybean mitogenactivated protein kinases (MAPKs) in salt stress response has yet to be characterized. In this study, we found that salt stress activates Glycine max MAP kinase 1 (GMK1), a soybean MAPK. The activity of GMK1 induced with increasing salt concentrations, up to 300 mM NaCl, after 5 min of the treatment and was regulated by post-translational modification. We found that mastoparan, a heteromeric G-protein activator,also activated GMK1, and that n-butanol, a phospholipase D inhibitor, and neomycin, a phospholipase C inhibitor, inhibited its activity. Moreover, GMK1 activity was reduced by suramin,a heteromeric G-protein inhibitor, and by two inhibitors of phosphatidic acid (PA) generation after 5 min of 300 mM NaCl treatment. Endogenous PA levels were highest 5 min after induction of salt stress, and exogenous PA directly activated GMK1. From these data, we propose that salt stress signaling is transduced from heteromeric G-protein to GMK1 via phospholipases in the early stages of the response to salt stress in soybean.

SALT-INDUCED CHLOROPLAST PROTEIN (SCP) is Involved in Plant Tolerance to Salt Stress in Arabidopsis

Yong Zhuang,Yangxuan Liu,Yuxiang Li,Ming Wei,Yuying Tang,Penghui Li,Zhijian Liu,Hui Li,Weizao Huang,Songhu Wang 한국식물학회 2019 Journal of Plant Biology Vol.62 No.6

Soil salinization threats the agricultural productionand food security worldwide. Salt stress induced plantsenescence and chloroplast degradation. However, it remainslargely unknown how the chloroplast-localized proteins affectplant response to salt stress. Here, we characterized a novelgene (At5g39520) in Arabidopsis, which is induced by saltstress and encodes a chloroplast-localized protein. Thus, thisgene was named SALT-INDUCED CHLOROPLAST PROTEIN(SCP). A T-DNA insertion mutant of SCP gene (scp-1)showed the enhanced tolerance to salt stress, as indicated bythe increased survival rates, fresh weights and chlorophyllcontents compared with wild type plants under salt treatment. Salt-induced leaf senescence was also delayed in scp-1 mutant. The scp-1 complementation line and SCP overexpressionlines displayed the hypersensitivity to salt stress. The qRTPCRanalysis indicated that the transcripts of CHLOROPLASTVESICULATION (CV), which mediates stress-inducedchloroplast degradation, were altered in scp-1 mutant andSCP overexpression lines. Taken together, our results suggestthat SCP gene plays a negative role in response to salt stress andhas potential application for genetic modification of improvingplant tolerance to salt stress.

Biological Inoculant of Salt-Tolerant Bacteria for Plant Growth Stimulation under Different Saline Soil Conditions

( Ru Wang ),( Chen Wang ),( Qing Feng ),( Rey-may Liou ),( Ying-feng Lin ) 한국미생물생명공학회(구 한국산업미생물학회) 2021 Journal of microbiology and biotechnology Vol.31 No.3

Using salt-tolerant bacteria to protect plants from salt stress is a promising microbiological treatment strategy for saline-alkali soil improvement. Here, we conducted research on the growth-promoting effect of Brevibacterium frigoritolerans on wheat under salt stress, which has rarely been addressed before. The synergistic effect of B. frigoritolerans combined with representative salt-tolerant bacteria Bacillus velezensis and Bacillus thuringiensis to promote the development of wheat under salt stress was also further studied. Our approach involved two steps: investigation of the plant growth-promoting traits of each strain at six salt stress levels (0, 2, 4, 6, 8, and 10%); examination of the effects of the strains (single or in combination) inoculated on wheat in different salt stress conditions (0, 50, 100, 200, 300, and 400 mM). The experiment of plant growth-promoting traits indicated that among three strains, B. frigoritolerans had the most potential for promoting wheat parameters. In single-strain inoculation, B. frigoritolerans showed the best performance of plant growth promotion. Moreover, a pot experiment proved that the plant growth-promoting potential of co-inoculation with three strains on wheat is better than single-strain inoculation under salt stress condition. Up to now, this is the first report suggesting that B. frigoritolerans has the potential to promote wheat growth under salt stress, especially combined with B. velezensis and B. thuringiensis.

Heat resistance of <i>Salmonella</i> Enteritidis under prolonged exposure to acid-salt combined stress and subsequent refrigeration

Kang, Il-Byeong,Kim, Dong-Hyeon,Jeong, Dana,Park, Jin-Hyeong,Seo, Kun-Ho Elsevier 2018 International journal of food microbiology Vol.285 No.-

<P><B>Abstract</B></P> <P> <I>Salmonella</I> Enteritidis is a major foodborne pathogen exposed to various environmental and preservation stresses in the food chain. Because adaptive responses of viable bacterial cells in the presence of sublethal stress can induce cross-protection against different stresses, we investigated the heat resistance of <I>Salmonella</I> Enteritidis at 60 °C under prolonged exposure to acid-salt combined stress and subsequent refrigeration. <I>Salmonella</I> Enteritidis was grown in tryptic soy broth at four pH values (4.5, 5.4, 6.4, and 7.3) and four NaCl concentrations (0%, 1%, 2%, and 3%) at 37 °C for 24 h and then incubated at 4 °C for 0, 1, 4, or 7 days. For 0 and 1 day-refrigerated cultures, previous adaptation to single stresses (acid or salt stress) increased the heat resistance of <I>Salmonella</I> Enteritidis, resulting in increased D-values, whereas the combination of acid and salt stress reduced heat tolerance; acid stress played a more critical role in mediating this effect than salt concentration. To elucidate the related mechanisms, the expression levels of heat shock sigma factors (<I>rpoH</I>) and heat shock genes (<I>dnaK</I> and <I>groEL</I>) were analyzed and found to be associated with the heat resistance of <I>Salmonella</I> Enteritidis. The refrigeration period was negatively correlated (<I>P</I> < 0.01) with the D-value (<I>r</I> = −0.505) and with the transcript levels of <I>rpoH</I> (<I>r</I> = −0.654), <I>dnaK</I> (<I>r</I> = −0.652), and <I>groEL</I> (<I>r</I> = −0.645). Our findings demonstrated that acid-salt combined preservation techniques and subsequent refrigeration may prevent <I>S</I>. Enteritidis survival in heat-pasteurized food products caused by cross-protection of acid or salt adapted cells.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We investigated heat resistance in <I>S</I>. Enteritidis at 60 °C under acid/salt stresses. </LI> <LI> Prior adaptation to single stresses increased the heat resistance of <I>S</I>. Enteritidis. </LI> <LI> The combination of acid/salt stresses reduced heat tolerance. </LI> <LI> <I>rpoH</I>, <I>dnaK</I>, and <I>groEL</I> gene expression levels were associated with heat resistance. </LI> <LI> Thus, combination preservation methods may prevent <I>S</I>. Enteritidis survival in foods. </LI> </UL> </P>

Comparative transcriptome analysis of salt-sensitive and salt-tolerant maize reveals potential mechanisms to enhance salt resistance

Mingquan Wang,Yufeng Wang,Yifei Zhang,Chunxia Li,Shichen Gong,Shuqin Yan,Guoliang Li,Guanghui Hu,Honglei Ren,Jianfei Yang,Tao Yu,Kejun Yang 한국유전학회 2019 Genes & Genomics Vol.41 No.7

Background Salt stress is a devastating environmental stress that causes plant growth inhibition and yield reduction. Objective The identification of salt-tolerant genes brings hope for the generation of salinity-tolerant crop plants through molecular breeding. Methods In this study, one salt-sensitive and one salt-tolerant maize inbred line were screened from 242 maize inbred lines. Reactive oxygen species (ROS)-related enzyme activities were detected and salt-responsive comparative transcriptome analysis was performed for control and 220 mM NaCl treated maize leaves. Results Salt-tolerant maize inbred line (L87) showed higher ROS-related enzyme (SOD, POD, APX and CAT) activities and accumulated relatively lower levels of ROS under salt stress. Of the total DEGs, 1856 upregulated DEGs were specific to L87, including stress tolerance-related members of the 70kDa family of heat shock proteins (Hsp70s) and aquaporins. The DEGs involved in the abscisic acid (ABA), ethylene, jasmonic acid (JA) and salicylic acid (SA) signal transduction pathways may determine the difference in salt tolerance between the two varieties, especially one central component SnRK2, that positively regulates ABA signaling and was only upregulated in L87. Analysis of DEGs related to ROS scavenging showed that some peroxidase (POD), glutathione S-transferase (GST), catalase (CAT) and superoxide dismutase (SOD) genes specific to L87 probably enhanced its salt tolerance. The analysis of differentially expressed transcription factors (TFs) suggested that WRKY TFs could contribute to the difference in salt tolerance between the two maize lines. Conclusion Compared with Salt-sensitive maize inbred line (L29), L87 exhibits specific regulatory mechanisms related to salt tolerance, including plant hormone interactions, ROS scavenging and the regulation of TFs. Our study identifies new candidate genes that may regulate maize tolerance to salt stress and provides useful information for breeding maize with high salt resistance.