Abiotic stress treatment reveals expansin like A gene OfEXLA1 improving salt and drought tolerance of Osmanthus fragrans by responding to abscisic acid

Sweet osmanthus(Osmanthus fragrans) is a having general approval aromatic tree in China that is widely applied to landscaping and gardening. However, the evergreen tree adaptability is limited by many environmental stresses. Currently, limited information is available regarding the genetic analysis and functional identification of expansin genes in response to abiotic stress in sweet osmanthus. In this study, a total of 29 expansin genes were identified and divided into four groups by genome-wide analysis from the sweet osmanthus genome. Transcriptome and quantitative Real-time PCR analysis showed that the cell wall-localized protein expansin-like A(OfEXLA1) gene was significantly induced by salt and drought treatment. Histochemical GUS staining of transgenic Arabidopsis lines in which GUS activity was driven with the OfEXLA1 promoter, GUS activity was significantly induced by salt, drought, and exogenous abscisic acid(ABA). In yeast, we found OfEXLA1overexpression significantly improved the population of cells compared with wild-type strains after NaCl and polyethylene glycol(PEG)treatment. Additionally, OfEXLA1 overexpression not only promoted plant growth, but also improved the salt and drought tolerance in Arabidopsis. To gain insight into the role of ABA signaling in the regulation of OfEXLA1 improving abiotic tolerance in sweet osmanthus, four differentially expressed ABA Insensitive 5(ABI5)-like genes(OfABL4, OfABL5, OfABL7, and OfABL8) were identified from transcriptome, and dualluciferase(dual-LUC) and yeast one hybrid(Y1H) assay showed that OfABL4 and OfABL5 might bind to OfEXLA1 promoter to accumulate the OfEXLA1 expression by responding to ABA signaling to improve abiotic tolerance in sweet osmanthus. These results provide the information for understanding the molecular functions of expansin-like A gene and molecular breeding of sweet osmanthus in future.

Strategies and prospects for melatonin to alleviate abiotic stress in horticultural plants

Melatonin is a conserved pleiotropic molecule in animals and plants.Melatonin is involved in many development processes and stress responses;thus,exploring its function in plants,particularly in horticultural plants,has become a rapidly developing field.Many studies have revealed that phytomelatonin acts as a plant biostimulant and increase its tolerance to various abiotic stressors,including extreme temperature,drought,osmotic disturbance,heavy metals,and ultraviolet(UV).Melatonin appears to have roles in the scavenging of reactive oxygen species(ROS)and other free radicals,affecting the primary and secondary metabolism of plants,regulating the transcripts of stress-related enzymes and transcription factors,and crosstalk with other hormones under different environmental conditions.This pleiotropy makes phytomelatonin an attractive regulator to improve resistance to abiotic stress in plants.The recent discovery of the potential phytomelatonin receptor CAND2/PMTR1 and the proposition of putative models related to the phytomelatonin signaling pathways makes phytomelatonin a new plant hormone.Based on relevant studies from our laboratory,this review summarizes the phytomelatonin biosynthetic and metabolic pathways in plants and the latest research progress on phytomelatonin in abiotic stress of horticultural plants.This study will provide a reference for elucidating the regulatory mechanism of phytomelatonin affecting the resistance to abiotic stress in plants.

Analysis and Characterization of the GABA Transaminase and Succinate Semialdehyde Dehydrogenase Genes in the Microalga Isochrysis zhanjiangensis in Response to Abiotic Stresses

Gamma-aminobutyric acid(GABA),widely existing in different organisms,is rapidly accumulated in plants in response to environmental stresses.The main biosynthesis and degradation pathways of GABA constitute the GABA shunt,which is tied to the tricarboxylic acid(TCA)cycle.GABA transaminase(GABA-T)and succinate semialdehyde dehydrogenase(SSADH)are two essential enzymes for the GABA degradation pathway.While there are abundant studies on GABA shunt in higher plants at the physiological and genetic levels,research on its role in microalgae remains limited.This study aimed at exploring the function of GABA-T and SSADH genes in Isochrysis zhanjiangensis,an important diet microalga,under different stresses.We cloned two GABA-T genes,IzGABA-T1 and IzGABA-T2,and one SSADH gene IzSSADH from Isochrysis zhanjiangensis and conducted heterologous expression experiments.The results showed that the overexpression of IzGABA-T1 or IzGABA-T2 enhanced the survival rates of yeast transformants under heat or NaCl stress,while the overexpression of IzSSADH improved yeast tolerance to NaCl stress but had no obvious effect on heat stress.Additionally,the results of quantitative real-time polymerase chain reaction(qPCR)showed that IzGABA-T1 transcription increased in the HT(salinity 25,35℃)and LS(salinity 15,25℃)groups.At 24 h,the IzGABA-T2 transcriptions increased in the HT,LS,and HS(salinity 35,25℃)groups,but their transcription levels decreased in all groups at 48 h.IzSSADH transcription increased in the LS group.These results suggest that IzGABA-T1,IzGABA-T2,and IzSSADH are associated with temperature and salinity stresses and possess a certain preference for different stresses.

The Correlation between Nutrition and Transport Mechanism under Abiotic Stress in Plants: A Comprehensive Review

Variations in the nutrients and water that plants require for metabolism,development,and the maintenance of cellular homeostasis are the main causes of abiotic stress in plants.It has,however,hardly ever been studied how these transporter proteins,such as aquaporin which is responsible for food and water intake in cell plasma mem-branes,interact with one another.This review aims to explore the interactions between nutrient transporters and aquaporins during water and nutrient uptake.It also investigates how symbiotic relationships influence the plant genome’s responses to regulatory processes such as photoperiodism,senescence,and nitrogenfixation.These responses are observed in reaction to various abiotic stresses.For instance,plasma membrane transporters are upregulated during macronutrient insufficiency,tonoplast transporters are overexpressed,and aquaporins are downregulated in micronutrient deficiency.Additionally,tolerant plants often exhibit increased expression of nutrient transporters and aquaporins in response to drought,salt,and cold temperatures.To better comprehend plant stress tolerance to abiotic challenges including starvation,K famine,salt,and freezing temperatures,both classes of nutrient and water transporters should be considered at the same time.

Genome wide investigation of Hsf gene family in Phoebe bournei:identification,evolution,and expression after abiotic stresses

Heat shock transcription factors(Hsfs)have important roles during plant growth and development and responses to abiotic stresses.The identification and func-tion of Hsf genes have been thoroughly studied in various herbaceous plant species,but not woody species,especially Phoebe bournei,an endangered,unique species in China.In this study,17 members of the Hsf gene family were identi-fied from P.bournei using bioinformatic methods.Phyloge-netic analysis indicated that PbHsf genes were grouped into three subfamilies:A,B,and C.Conserved motifs,three-dimensional structure,and physicochemical properties of the PbHsf proteins were also analyzed.The structure of the PbHsf genes varied in the number of exons and introns.Pre-diction of cis-acting elements in the promoter region indi-cated that PbHsf genes are likely involved in responses to plant hormones and stresses.A collinearity analysis dem-onstrated that expansions of the PbHsf gene family mainly take place via segmental duplication.The expression levels of PbHsf genes varied across different plant tissues.On the basis of the expression profiles of five representative PbHsf genes during heat,cold,salt,and drought stress,PbHsf pro-teins seem to have multiple functions depending on the type of abiotic stress.This systematic,genome-wide investigation of PbHsf genes in P.bournei and their expression patterns provides valuable insights and information for further func-tional dissection of Hsf proteins in this endangered,unique species.

Upregulation of the glycine-rich protein-encoding gene GhGRPL enhances plant tolerance to abiotic and biotic stressors by promoting secondary cell wall development

Abiotic and biotic stressors adversely affect plant survival,biomass generation,and crop yields.As the global availability of arable land declines and the impacts of global warming intensify,such stressors may have increasingly pronounced effects on agricultural productivity.Currently,researchers face the overarching challenge of comprehensively enhancing plant resilience to abiotic and biotic stressors.The secondary cell wall plays a crucial role in bolstering the stress resistance of plants.To increase plant resistance to stress through genetic manipulation of the secondary cell wall,we cloned a cell wall protein designated glycine-rich protein-like(GhGRPL)from cotton fibers,and found that it is specifically expressed during the period of secondary cell wall biosynthesis.Notably,this protein differs from its Arabidopsis homolog,AtGRP,since its glycine-rich domain is deficient in glycine residues.GhGRPL is involved in secondary cell wall deposition.Upregulation of GhGRPL enhances lignin accumulation and,consequently,the thickness of the secondary cell walls,thereby increasing the plant’s resistance to abiotic stressors,such as drought and salinity,and biotic threats,including Verticillium dahliae infection.Conversely,interference with GhGRPL expression in cotton reduces lignin accumulation and compromises that resistance.Taken together,our findings elucidate the role of GhGRPL in regulating secondary cell wall development through its influence on lignin deposition,which,in turn,reinforces cell wall robustness and impermeability.These findings highlight the promising near-future prospect of adopting GhGRPL as a viable,effective approach for enhancing plant resilience to abiotic and biotic stress factors.

Genome-Wide Identification and Expression Analysis of the GSK3 Gene Family in Sunflower under Various Abiotic Stresses

Genes in the glycogen synthase kinase 3(GSK3)family are essential in regulating plant response to stressful conditions.This study employed bioinformatics to uncover the GSK3 gene family from the sunflower genome database.The expressions of GSK3 genes in different tissues and stress treatments,such as salt,drought,and cold,were assessed using transcriptome sequencing and quantitative real-time PCR(qRT-PCR).The study results revealed that the 12 GSK3 genes of sunflower,belonging to four classes(Classes I–IV),contained the GSK3 kinase domain and 11–13 exons.The majority of GSK3 genes were highly expressed in the leaf axil and flower,while their expression levels were relatively lower in the leaf.As a result of salt stress,six of the GSK3 genes(HaSK11,HaSK22,HaSK23,HaSK32,HaSK33,and HaSK41)displayed a notable increase in expression,while HaSK14 and HaSK21 experienced a significant decrease.With regard to drought stress,five of the GSK3 genes(HaSK11,HaSK13,HaSK21,HaSK22,and HaSK33)experienced a remarkable rise in expression.When exposed to cold stress,seven of the GSK3 genes(HaSK11,HaSK12,HaSK13,HaSK32,HaSK33,HaSK41,and HaSK42)showed a substantial increase,whereas HaSK21 and HaSK23 had a sharp decline.This research is of great importance in understanding the abiotic resistance mechanism of sunflowers and developing new varieties with improved stress resistance.

Abiotic and Biotic Factors Controlling Grain Aroma along Value Chain of Fragrant Rice:A Review

The aroma of fragrant rice is one of the grain quality attributes that significantly influenceconsumer preferences and prices in world markets. The volatile compound 2-acetyl-1-pyrroline (2AP) isrecognized as a key component of the aroma in fragrant rice. The variation in grain 2AP content amongvarious fragrant rice varieties is associated with the expression of the badh2 gene, with 19 alleles havingbeen identified so far. The grain 2AP content is strongly influenced by environmental and managementfactors during cultivation as well as post-harvest conditions. This review pinpointed the major abiotic andbiotic factors that control grain 2AP content. Abiotic factors refer to water, temperature, light quality,fertilizer application (both macro- and micro-nutrients), and soil properties, including salinity, while bioticfactors include microorganisms that produce aromatic compounds, thus influencing the grain aroma infragrant rice. Post-harvest management, including storage and drying conditions, can significantly impactthe grain 2AP content, and proper post-harvest conditions can intensify the grain aroma. This reviewsuggests that there are rice varieties that can serve as potential sources of genetic material for breedingrice varieties with high grain aroma content. It offers an overview of recent research on the major factorsaffecting the aroma content in fragrant rice. This knowledge will facilitate further research on theproduction of high-quality rice to meet the demands of farmers and consumers.

Abiotic Factors Associated with Abundance Dynamics and Antibiotic Multidrug Resistance of Escherichia coli and Enterococcus faecalis Isolated from Some Ombessa Aquatic Systems (Central Cameroon Region)

The present study conducted in the town of Ombessa aims to assess the influence of abiotic factors on the abundance dynamics and antibiotic susceptibility of Escherichia coli and Enterococcus faecalis isolated from some aquatic systems from February to July 2022, monthly samples were taken at 10 water points used by the population (8 groundwater points and 2 surface water points). Samples were analyzed for physico-chemical parameters such as temperature, pH, electrical conductivity. Bacteriological variables such as BHAM, E. coli and E. faecalis abundances were also assessed. Antibiotic susceptibility of E. coli and E. faecalis was assessed using 06 antibiotics using the Kirby-Bauer diffusion disk method. The results show that bacterial abundances were the highest in surface waters. Bacterial densities were the highest in May and the lowest in February. The average densities recorded were 3845 CFU/100mL for BHAM, 380 CFU/100mL for E. coli and 14 CFU/100mL for E. faecalis in groundwater;and 8583 CFU/100mL for BHAM, 6878 CFU/100mL for E. coli and 812 CFU/100mL for E. faecalis in surface water. Antibiotic susceptibility tests showed that these bacterial species are sensitive to Gentamicin, Chloramphenicol, Azithromycin and Ciprofloxacin. They are all resistant to Trimethoprim/Sulfamethoxazole, E. coli is resistant to Doxycycline and E. faecalis has an intermediate sensitivity to Gentamicin. Overall, the Multiresistance to Antibiotics (MRA) indices obtained were above 0.2, indicating the presence of multidrug resistance in bacterial communities. The physico-chemical properties of the water varied over time and space, but on the whole remained below the threshold values of WHO guidelines. The degree of linkage between abiotic water variables and bacteriological parameters has shown that bacterial densities are more abundant in rainy seasons and increased O2 levels favor bacterial growth, while TSS, CO2 and dissolved nitrate levels affect the sensitivity of these bacterial species to antibiotics.

Genome-wide identification of TPS genes in sesame and analysis of their expression in response to abiotic stresses

Trehalose and its precursor,trehalose-6-phosphate,play critical roles in plant metabolism and response to abiotic stresses.Trehalose-6-phosphate synthase(TPS)is a key enzyme in the trehalose synthesis pathway.Hence this study identified TPS genes in sesame(SiTPSs)and examined their expression patterns under various abiotic stresses.Totally,ten SiTPSs were identified and comprehensively characterized.SiTPSs were found to be unevenly distributed on five out of 13 sesame chromosomes and were predicted to be localized in chloroplasts and vacuoles of cells.Phylogenetic analysis classified SiTPS proteins into two groups(I and II),which was supported by gene structure and conserved motif analyses.Analysis of cis-acting elements in promoter regions of SiTPSs revealed that they might primarily involve developmental and environmental responses.SiTPSs exhibited different expression patterns in different tissues and under different abiotic stresses.Most group II SiTPS genes(SiTPS4-SiTPS10)were strongly induced by drought,salt,waterlogging,and osmotic stress.Particularly,SiTPS10 was the most significantly up-regulated under various abiotic stresses,indicating it is a candidate gene for improving sesame tolerance to multiple abiotic stresses.Our results provide insight into the TPS gene family in sesame and fundamental resources for genomics studies towards dissecting SiTPS genes’functions.

Deciphering the Origin of Abiotic Organic Compounds on Earth:Review and Future Prospects

The geologic production of abiotic organic compounds has been the subject of increasing scientific attention due to their use in the global carbon flux balance,by chemosynthetic biological communities,and for energy resources.Extensive analysis of methane(CH_(4))and other organics in diverse geologic settings,combined with thermodynamic modelings and laboratory simulations,have yielded insights into the distribution of specific abiotic organic molecules on Earth and the favorable conditions and pathways under which they form.This updated and comprehensive review summarizes published results of petrological,thermodynamic,and experimental investigations of possible pathways for the formation of particular species of abiotic simple hydrocarbon molecules such as CH_(4),and of complex hydrocarbon systems,e.g.,long-chain hydrocarbons and even solid carbonaceous matters,in various geologic processes,distinguished into three classes:(1)pre-to early planetary processes;(2)mantle and magmatic processes;and(3)the gas/water-rock reaction processes in low-pressure ultramafic rock and high-pressure subduction zone systems.We not only emphasize how organics are abiotically synthesized but also explore the role or changes of organics in evolutionary geological environments after synthesis,such as phase transitions or organic-mineral interactions.Correspondingly,there is an urgent need to explore the diversity of abiotic organic compounds prevailing on Earth.

Defensive Role of Plant Hormones in Advancing Abiotic Stress-Resistant Rice Plants

Consistent climatic perturbations have increased global environmental concerns, especially the impacts of abiotic stresses on crop productivity. Rice is a staple food crop for the majority of the world’s population. Abiotic stresses, including salt, drought, heat, cold and heavy metals, are potential inhibitors of rice growth and yield. Abiotic stresses elicit various acclimation responses that facilitate in stress mitigation. Plant hormones play an important role in mediating the growth and development of rice plants under optimal and stressful environments by activating a multitude of signalling cascades to elicit the rice plant’s adaptive responses. The current review describes the role of plant hormone-mediated abiotic stress tolerance in rice, potential crosstalk between plant hormones involved in rice abiotic stress tolerance and significant advancements in biotechnological initiatives including genetic engineering approach to provide a step forward in making rice resistance to abiotic stress.

Identification and Characterization of ZF-HD Genes in Response to Abscisic Acid and Abiotic Stresses in Maize

The zinc finger homeodomain(ZF-HD)genes belong to the homeobox gene family,playing critical roles in flower development and stress response.Despite their importance,however,to date there has been no genome-wide identification and characterization of the ZF-HD genes that are probably involved in stress responses in maize.In this study,24 ZF-HD genes were identified,and their chromosomal locations,protein properties,duplication patterns,structures,conserved motifs and expression patterns were investigated.The results revealed that the ZF-HD genes are unevenly distributed on nine chromosomes and that most of these genes lack introns.Six and two ZF-HD genes have undergone segmental and tandem duplication,respectively,during genome expansion.These 24 ZF-HD transcription factors were classified into six major groups on the basis of protein molecular evolutionary relationship.The expression profiles of these genes in different tissues were evaluated,resulting in producing two distinct clusters.ZF-HD genes are preferentially expressed in reproductive tissues.Furthermore,expression profiles of the 24 ZF-HD genes in response to different kinds of stresses revealed that ten genes were simultaneously up-regulated under ABA,salt and PEG treatments;meanwhile four genes were simultaneously down-regulated.These findings will pave the way for deciphering the function and mechanism of ZF-HD genes on how to implicate in abiotic stress.

Mechanisms of autophagy function and regulation in plant growth,development,and response to abiotic stress

Autophagy is an evolutionarily conserved degradation pathway of lysosomes(in mammals)and vacuoles(in yeasts and plants)from lower yeasts to higher mammals.It wraps unwanted organelles and damaged proteins in a double-membrane structure to transport them to vacuoles for degradation and recycling.In plants,autophagy functions in adaptation to the environment and maintenance of growth and development.This review systematically describes the autophagy process,biological functions,and regulatory mechanisms occurring during plant growth and development and in response to abiotic stresses.It provides a basis for further theoretical research and guidance of agricultural production.

Hormetic effects of abiotic environmental stressors in woody plants in the context of climate change

Woody plants contribute to the stability and productivity of terrestrial ecosystems and are significantly affected by climate change.According to the concept of environmental hormesis,any environmental stressors can cause hormesis,that is,stimulation in low doses and inhibition in high doses.Numerous studies have demonstrated plant hormesis under low doses of various abiotic stressors.However,the hormetic responses of woody plants to abiotic stressors from climate change are insufficiently studied.This review analyses data on the stimulating effects of low doses of climate stressors in experiments and in real ecosystems.Numerous laboratory and field experiments show that single and combined exposure to various climate stressors(temperature,humidity,and elevated carbon dioxide concentrations) can cause hormesis in various species and functional types of woody plants,which can be accompanied by hormetic trade-offs and preconditioning.In addition,there is evidence of climate hormesis in woody plants in ecosystem conditions.Field experiments in various ecosystems show that elevated temperatures and/or precipitation or elevated carbon dioxide concentrations causing hormesis in dominant tree species can stimulate ecosystem productivity.Moreover,climate hormesis of the growth and reproduction of dominant forest tree species contributes to the spread of forests,that is,climate-driven ecological succession.The main commonalities of climate hormesis in woody species include:(1) Low-dose climate stressors cause hormesis in woody plants when strong(limiting) stressors do not affect plants or these limiting stressors are mitigated by climate change.(2) Hormesis can occur with the direct impact of climatic stressors on trees and with the indirect impact of these stressors on plants through other parts of the ecosystem.(3)Climate stressor interactions(e.g.,synergism,antagonism)can affect hormesis.(4) Hormesis may disappear due to tree acclimatization with consequent changes in the range of tolerances to climate factors.This review highlights the need for targeted studies of climate hormesis in woody species and its role in the adaptation of forest ecosystems to climate change.

The nuclear export receptor OsXPO1 is required for rice development and involved in abiotic stress responses

The transport of proteins to and from the nucleus is necessary for many cellular processes and is one of the ways plants respond to developmental signals and environmental stresses.Nucleocytoplasmic trafficking of proteins is mediated by the nuclear transport receptor(NTR).Although NTR has been extensively studied in humans and Arabidopsis,it has rarely been identified and functionally characterized in rice.In this study,we identified exportin 1 in rice(OsXPO1)as a nuclear export receptor.OsXPO1shares high protein identity with its functional homologs in Arabidopsis and other organisms.OsXPO1localized to both the nucleus and the cytoplasm,directly interacted with the small GTPases OsRAN1and OsRAN2 in the nucleus,and mediated their nuclear export.Loss-of-function osxpo1 mutations were lethal at the seedling stage.Suppression of OsXPO1 expression in RNA interference lines produced multifaceted developmental defects,including arrested growth,premature senescence,abnormal inflorescence,and brown and mouth-opened spikelets.Overexpression of OsXPO1 in rice reduced plant height and seed-setting rate,but increased plant tolerance in response to PEG-mimicked drought stress and salt stress.These results indicate that OsXPO1 is a nuclear export receptor and acts in regulating plant development and abiotic stress responses.

What Do Seedlings Like? The Relationship between Seedling Richness and Abundance with Abiotic Factors

Natural regeneration is the interaction of natural processes to restore the forest ecosystem. Its dynamics are influenced by the intensity and extent of a series of abiotic and biotic factors, which may be intrinsic or extrinsic. Knowing the importance of establishing natural regeneration within forest ecosystems, this work aimed to evaluate whether litter depth and trail distance influenced seedling abundance and richness in a forest fragment undergoing natural restoration. The hypothesis tested in this research was that abiotic factors influence the natural regeneration of this forest since they are factors that are directly linked to seed germination and seedling establishment. 30 plots of 1 m2 were randomly analyzed within the forest located on the brown trail. A millimeter ruler was used to diagnose the litter depth and a measuring tape to measure the distance from the plot to the edge. In each plot the seedlings were morpho-specified and each morphospecies had the number of individuals counted. Linear regression tests were performed to assess the relationships between species richness and trail distance and litter depth. The same was done for species abundance. All results showed that there is no relationship pattern between any of the variables. Other factors also influence the regeneration of a forest, such as luminosity and seed bank. Furthermore, litter depth is related to the successional stage of the forest. It was concluded that the abiotic factors tested do not influence the regeneration of the study area.

Abiotic Methane Reservoirs in the Western Tianshan HP–UHP Metamorphic Belt,China

Natural gas,consisting primarily of methane(CH_(4)),has become a major source of clean energy in modern society in many parts of the globe.Recent experimental observations and discoveries of deep-sourced abiotic CH_(4)in cold subduction zones indicate the important ability of cold subducted slabs to generate natural gas reservoirs.However,most CH_(4)flux and reservoirs remain unknown and their potential is overlooked in global carbon flux estimations.Massive abiotic CH_(4)-rich fluid inclusions(FIs)in garnet and omphacite from ultrahigh-pressure(UHP)eclogites have been found in the Western Tianshan(WT)UHP metamorphic belt,which provides one ideal case for quantification of abiotic CH_(4)stored in the cold subducted crust.By two methods,we assess the abiotic CH_(4)content stored in the Chinese WT HP–UHP metamorphic belt.Our calculations show that at least 113 Mt CH_(4)is stored in the WT eclogites.We also discuss the implications for CH_(4)reservoirs in subduction zones worldwide and speculate that the cold subduction zones may represent one of the largest,yet overlooked,sources of abiotic CH_(4)on Earth,which should not be ignored in the global natural resource and carbon flux estimations.

Isolation of an Arabidopsis Gene Encoding Ins (1,3,4) P_3 5/6-Kinase-like Protein and Involved in Plant Response to Abiotic Stresses

By mRNA differential display from control versus NaCl_shocked Arabidopsis seedlings, we screened an Arabidopsis 3′ partial cDNA, which represents a gene encoding inositol 1,3,4_trisphosphate (Ins(1,3,4)P 3) 5/6_kinase_like protein. Northern blotting analysis showed that the gene, named as AtITL1, is strongly induced by NaCl and low temperature, but not induced by drought and abscisic acid (ABA). Analysis of 5′ region of the AtITL1 found that there are dehydration_responsive element/C_repeat (DRE/CRT) cis _acting elements, but no elements related to G_box and ABRE (ABA_responsive element) in its 5′ region, which is consistent with the expression patterns of the AtITL1 independent of ABA. These results suggest that the AtITL1 may be involved in the osmotic stress response pathway independent of ABA.

The Expression of RcLEA Gene Improves Tolerance of E. coli Cells to Abiotic Stress

[Objective] This study was to reveal the heat induced expression model of RcLEA gene and its tolerance to various abiotic stresses.[Method] Heat resistant and heat sensitive varieties of Rosa hybrida L.were subjected to heat shock treatment at 38 ℃ for 3 h;then RcLEA gene from both varieties treated was cloned and transformed into Escherichia coli strain BL21;finally recombinant colonies were separately cultured at 4 ℃ and 50 ℃ under the stresses of LiCl,NaCl,Na2CO3,CdCl2 and H2O2 to study the responses of recombinant E.coli strains to high temperature,low temperature and some other abiotic stresses.[Result] After heat shock treatment at 38 ℃ for 3 h,RcLEA gene expressed highly in ＇Schloss mannieim＇（SM）and ＇Las vegas＇（LV）variety,but weakly or even not expressed in ＇Kordes＇ Perfecta＇（KP）,indicating that this gene is closely related with heat resistance of R.hybrida.Compared with WT strains,recombinant clones showed higher tolerance to abiotic stresses including high temperature,low temperature,heavy metal,high salt,high pH value and oxidation,suggesting that RcLEA is concerned with the response of R.hybrida to abiotic stresses mentioned above.[Conclusion] These results provide thoughts for increasing heat resistance by introducing RcLEA into heat sensitive R.hybrida varieties and studying the heat-resistant mechanism of R.hybrida,and also provide theoretical support for selecting heat resistant variety of landscape and ornamental plants like R.hybrida.