Involvement of the ABA-and H_(2)O_(2)-Mediated Ascorbate-Glutathione Cycle in the Drought Stress Responses of Wheat Roots

Abscisic acid(ABA),hydrogen peroxide(H_(2)O_(2)) and ascorbate(AsA)–glutathione(GSH)cycle are widely known for their participation in various stresses.However,the relationship between ABA and H_(2)O_(2) levels and the AsA–GSH cycle under drought stress in wheat has not been studied.In this study,a hydroponic experiment was conducted in wheat seedlings subjected to 15%polyethylene glycol(PEG)6000–induced dehydration.Drought stress caused the rapid accumulation of endogenous ABA and H_(2)O_(2) and significantly decreased the number of root tips compared with the control.The application of ABA significantly increased the number of root tips,whereas the application of H_(2)O_(2) markedly reduced the number of root tips,compared with that under 15%PEG-6000.In addition,drought stress markedly increased the DHA,GSH and GSSG levels,but decreased the AsA levels,AsA/DHA and GSH/GSSG ratios compared with those in the control.The activities of the four enzymes in the AsA–GSH cycle were also markedly increased under drought stress,including glutathione reductase(GR),ascorbate peroxidase(APX),monodehydroascorbate reductase(MDHAR)and dehydroascorbate reductase(DHAR),compared with those in the control.However,the application of an ABA inhibitor significantly inhibited GR,DHAR and APX activities,whereas the application of an H_(2)O_(2) inhibitor significantly inhibited DHAR and MDHAR activities.Furthermore,the application of ABA inhibitor significantly promoted the increases of H_(2)O_(2) and the application of H_(2)O_(2) inhibitor significantly blocked the increases of ABA,compared with those under 15% PEG-6000.Taken together,the results indicated that ABA and H_(2)O_(2) probably interact under drought stress in wheat;and both of them can mediate drought stress by modulating the enzymes in AsA–GSH cycle,where ABA acts as the main regulator of GR,DHAR,and APX activities,and H_(2)O_(2) acts as the main regulator of DHAR and MDHAR activities.

Biomechanical behavior of grass roots at different gauge lengths

Gauge length influences the biomechanical properties of herbaceous roots such as tensile resistance,tensile strength and Young’s modulus.However,the extent to which and how these biomechanical properties of herbaceous roots are influenced remain unknown.To better understand the behavior of roots in tension under different conditions and to illustrate these behaviors,uniaxial tensile tests were conducted on the Poa araratica roots as the gauge length increased from 20 mm to 80 mm.Subsequently,ANOVA was used to test the impact of the significant influences of gauge length on the biomechanical properties,nonlinear regression was applied to establish the variation in the biomechanical properties with gauge length to answer the question of the extent to which the biomechanical properties are influenced,and Weibull models were subsequently introduced to illustrate how the biomechanical properties are influenced by gauge length.The results reveal that(1)the variation in biomechanical properties with root diameter depends on both the gauge length and the properties themselves;(2)the gauge length significantly impacts most of the biomechanical properties;(3)the tensile resistance,tensile strength,and tensile strain at cracks decrease as the gauge length increases,with values decreasing by 20%-300%,while Young’s modulus exhibits the opposite trend,with a corresponding increase of 30%;and(4)the Weibull distribution is suitable for describing the probability distribution of these biomechanical properties;the Weibull modulus for both tensile resistance and tensile strain at cracks linearly decrease with gauge length,whereas those for tensile strength and Young’s modulus exhibit the opposite trend.The tensile resistance,tensile strength,and tensile strain at the cracks linearly decrease with increasing gauge length,while the tensile strength and Young’s modulus linearly increase with increasing gauge length.

The response of roots and the rhizosphere environment to integrative cultivation practices in paddy rice

Integrative cultivation practices(ICPs)are essential for enhancing cereal yield and resource use efficiency.However,the effects of ICP on the rhizosphere environment and roots of paddy rice are still poorly understood.In this study,four rice varieties were produced in the field.Each variety was treated with six different cultivation techniques,including zero nitrogen application(0 N),local farmers’practice(LFP),nitrogen reduction(NR),and three progressive ICP techniques comprised of enhanced fertilizer N practice and increased plant density(ICP1),a treatment similar to ICP1 but with alternate wetting and moderate drying instead of continuous flooding(ICP2),and the same practices as ICP2 with the application of organic fertilizer(ICP3).The ICPs had greater grain production and nitrogen use efficiency than the other three methods.Root length,dry weight,root diameter,activity of root oxidation,root bleeding rate,zeatin and zeatin riboside compositions,and total organic acids in root exudates were elevated with the introduction of the successive cultivation practices.ICPs enhanced nitrate nitrogen,the activities of urease and invertase,and the diversity of microbes(bacteria)in rhizosphere and non-rhizosphere soil,while reducing the ammonium nitrogen content.The nutrient contents(ammonium nitrogen,total nitrogen,total potassium,total phosphorus,nitrate,and available phosphorus)and urease activity in rhizosphere soil were reduced in all treatments in comparison with the non-rhizosphere soil,but the invertase activity and bacterial diversity were greater.The main root morphology and physiology,and the ammonium nitrogen contents in rhizosphere soil at the primary stages were closely correlated with grain yield and internal nitrogen use efficiency.These findings suggest that the coordinated enhancement of the root system and the environment of the rhizosphere under integrative cultivation approaches may lead to higher rice production.

The osteoclastic activity in apical distal region of molar mesial roots affects orthodontic tooth movement and root resorption in rats

The utilization of optimal orthodontic force is crucial to prevent undesirable side effects and ensure efficient tooth movement during orthodontic treatment.However,the sensitivity of existing detection techniques is not sufficient,and the criteria for evaluating optimal force have not been yet established.Here,by employing 3D finite element analysis methodology,we found that the apical distal region(A-D region)of mesial roots is particularly sensitive to orthodontic force in rats.Tartrate-resistant acidic phosphatase(TRAP)-positive osteoclasts began accumulating in the A-D region under the force of 40 grams(g),leading to alveolar bone resorption and tooth movement.When the force reached 80 g,TRAP-positive osteoclasts started appearing on the root surface in the A-D region.Additionally,micro-computed tomography revealed a significant root resorption at 80 g.Notably,the A-D region was identified as a major contributor to whole root resorption.It was determined that 40 g is the minimum effective force for tooth movement with minimal side effects according to the analysis of tooth movement,inclination,and hyalinization.These findings suggest that the A-D region with its changes on the root surface is an important consideration and sensitive indicator when evaluating orthodontic forces for a rat model.Collectively,our investigations into this region would aid in offering valuable implications for preventing and minimizing root resorption during patients’orthodontic treatment.

Fast,simple,efficient Agrobacterium rhizogenes-mediated transformation system to non-heading Chinese cabbage with transgenic roots

Non-heading Chinese cabbage, a variety of Brassica campestris, is an important vegetable crop in the Yangtze River Basin of China. However,the immaturity of its stable transformation system and its low transformation efficiency limit gene function research on non-heading Chinese cabbage. Agrobacterium rhizogenes-mediated(ARM) transgenic technology is a rapid and effective transformation method that has not yet been established for non-heading Chinese cabbage plants. Here, we optimized conventional ARM approaches(one-step and two-step transformation methods) suitable for living non-heading Chinese cabbage plants in nonsterile environments. Transgenic roots in composite non-heading Chinese cabbage plants were identified using phenotypic detection, fluorescence observation, and PCR analysis. The transformation efficiency of a two-step method on four five-day-old non-heading Chinese cabbage seedlings(Suzhouqing, Huangmeigui, Wuyueman, and Sijiu Caixin) was 43.33%-51.09%, whereas using the stout hypocotyl resulted in a transformation efficiency of 54.88% for the 30-day-old Sijiu Caixin.The one-step method outperformed the two-step method;the transformation efficiency of different varieties was above 60%, and both methods can be used to obtain transgenic roots for functional studies within one month. Finally, optimized ARM transformation methods can easily,quickly, and effectively produce composite non-heading Chinese cabbage plants with transgenic roots, providing a reliable foundation for gene function research and non-heading Chinese cabbage genetic improvement breeding.

Optimization of Enzymatic Extraction Process of Polysaccharides from Pseudostellaria heterophylla Fibrous Roots by Response Surface Methodology and Its Pilot Application

[Objectives]To study and optimize the process conditions of enzymatic hydrolysis technology for extracting polysaccharides from Pseudostellaria heterophylla fibrous roots and its application in workshop pilot tests.[Methods]P.heterophylla fibrous roots were taken as the matrix material,and Box Behnken design was used to analyze the extraction time,composite enzyme addition amount,and liquid-solid ratio for response surface optimization experiments,and then applied to the pilot extraction of P.heterophylla fibrous roots.[Results]Response surface analysis showed that all factors had a significant impact on the experimental indicators.The optimal extraction process conditions for polysaccharides from P.heterophylla fibrous roots were extraction time of 2.7 h,compound enzyme addition of 2.5%,and liquid-solid ratio of 32.The yield of polysaccharides from P.heterophylla fibrous roots was 4.83%.The water extraction process of P.heterophylla fibrous roots extraction pilot was used as the control group for response surface optimization of the pilot experiment.The optimization results showed that the extraction time was 3 h,the amount of composite enzyme added was 2.5%,and the liquid-solid ratio was 28.The polysaccharide yield was 4.75%,an increase of 4.63%compared to the control group.[Conclusions]This paper could provide feasibility for the innovation of enzy-matic hydrolysis technology for P.heterophylla fibrous roots and its workshop pilot practice application,as well as a reference for the industrial application of its medicinal resources.

Broad Hormonal Responses Induced by Aluminum in Roots of Dwarf Transgenics of Solanum lycopersicum L. cv “Micro-Tom”

The spatial pattern distribution of plant hormones in response to aluminum (Al) toxicity in roots remains to be shown. This study was performed to assess the root hormonal accumulation and gene expression in response to Al toxicity in five transgenic miniature dwarf tomatoes cv. Micro-Tom (MT). MT and MT transgenics to acid indole acetic, cytokinin, gibberellin, abscisic acid and ethylene were cultivated in nutrient solutions containing different Al concentrations. Root growth elongation was measured and cellular damage was visualized by staining Evans’s blue. The GUS reporter gene staining technique was used to visualize hormonal changes in MT apex root tissues. Data indicated that the MT is sensitive to Al that induced significant growth inhibition and cellular damage. Al concentration of 27 μM was significantly toxic, inducing root apex darkening and inhibition of root development. The qualitative evaluation of GUS reporter gene expression showed intense crosstalk among all hormones studied, underscoring the complexity of signaling induced by Al in apex roots. Results point out to a major understanding of the hormonal signaling in response to Al toxicity, which may induce a change of root growth and architecture with growth inhibition and cell constraints modulated by all different hormones evaluated.

Differential Gene Expression Between Wheat Hybrids and Their Parental Inbreds in Primary Roots

To provide an insight into the molecular basis of heterosis, differential display of mRNA was used to analyze the difference of gene expression between wheat (Triticum aestivum L.) heterotic hybrid A, nonheterotic hybrid B and their parental inbreds in the primary roots. By using 5′ end random primers in combination with three one-base-anchored primers, it was found that 22.5% and 22.9% of 877 total displayed cDNAs were differentially expressed between hybrid A, B and their parents, respectively. Both quantitative and qualitative differences in gene expression between hybrids and their parental inbreds were obvious, indicating that the patterns of gene expression in hybrids alter significantly as compared to their corresponding parents. On the other hand, by using MADS-box gene specific 5′ end primer for DDRT-PCR, we found that nearly all of the displayed cDNA fragments were polymorphic between hybrids and their parents, and major difference occurred in qualitative level, in which hybrid specific-expressed and silenced genes are the major two patterns, suggesting that MADS-box gene may be important for manifestation of differential gene expression and wheat heterosis. In comparison with our previous results by using seedling leaves, it is indicated that differential gene expression between hybrids and parents is dependent on the tissues tested, and more differentially expressed genes were observed in the primary roots than in the seedling leaves. Therefore, it is concluded that the expressions of both randomly displayed cDNAs and transcription factor genes, such as MADS-box, alter significantly between hybrids and their parents, which might be responsible for the observed heterosis.

Organic Acids Secreted from Plant Roots under Soil Stress and Their Effects on Ecological Adaptability of Plants

[Objective] In this study,the secretion of organic acids from plant roots under soil nutrient and water stress and the effects of organic acids on ecological adaptability of plants were investigated,which provided theoretical basis for improving the adaptability of plants to a variety of stress conditions.The results showed that,under nutrient and water stress,the content of organic acids secreted from plant roots increased significantly as a common active adaptive response.Organic acids could improve the activities of a variety of antioxidant enzymes,contents of osmotic regulatory substances,contents of chlorophyll and photosynthesis levels,promote nutrient absorption and transportation in plants,and ultimately contribute to plant growth and biomass accumulation,reduce the toxicity of stress conditions to plants and improve the stress resistance and adaptability of plants.

Study on the Antimicrobial Effect of the Extracts of Clerodendron bungei Roots

[ Objective ] The aim was to research the antimicrobial effect of the extracts of Clerodendron bungei roots with different solvents on the common plant microbes. [ Method] The bacteria cake method was used to study the antimicrobial capability of Clerodendron bungei roots. [ Result ] The extracts have anti-bacterial action on Rhixoctonia cerealis V. Hoeven, Fusarium graminearum, Rhizoctonia solani and Setosphaeria turcica, especially the extract from distilled water has the strongest anti-bacterial action on Rhixoctonia cerealis V. Hoeven and Fusarium graminearum, the extract from ether has the strongest anti-bacterial action on Fusarium graminearum, the MIC all were 10 mg/ml. The extracts had different antimicrobial effect when pH value was from 5 to 8[ Conclusion] The extracts of Clerodendron bungei roots could inhibit the 4 pathogenic microorganism, and the antibacterial activity was affected by pH value greatly.

Effects of Uniconazole on Physiological and Biochemical Properties of Roots of Different Sweetpotato Cultivars at Seedling Stage

Objective] This study almed to investigate the effects of uniconazoIe on physioIogical and biochemical properties of roots of different sweetpotato cuItivars at seedIing stage. [Method] Under hydroponic conditions in a greenhouse, the effects of exogenous uniconazoIe on physioIogical and biochemical properties of roots of different sweetpotato cuItivars at seedIing stage were analyzed under continuous drought stress simuIated by PEG-6000. [Result] Compared with normal water suppIy treatment （N）, drought treatment （D） decreased significantIy root Iength, root surface area, average root diameter and root voIume of Jishu 21 and Jihei 1; to be specif-ic, compared with Jishu 21, root Iength, root surface area and average root diame-ter of Jihei 1 decreased greatIy, but root voIume of Jihei 1 decreased sIightIy. SOD, POD, APX activities and MDA content of Jishu 21 and Jihei 1 increased, and root vitality of two sweetpotato cuItivars was reduced; to be specific, compared with Jihei 1, Jishu 21 exhibited significantIy improved SOD, POD, APX activities, sIightIy im-proved MDA content and remarkabIy reduced root vitality. IAA, GAs and ZR con-tents of Jishu 21 and Jihei 1 decIined at seedIing stage; ABA content of two sweetpotato cuItivars was improved; to be specific, compared with Jihei 1, IAA, GAs and ZR contents of Jishu 21 were reduced sIightIy, whiIe ABA content of Jishu 21 was improved sIightIy. Under stress conditions, uniconazoIe treatment increased sig-nificantIy root Iength and root surface area of Jihei 1 and increased sIightIy root voIume of Jihei 1 compared with Jishu 21; uniconazoIe treatment increased signifi-cantIy SOD, POD and APX activities and root vitality of Jihei 1 and decIined re-markabIy MDA content of Jihei 1 compared with Jishu 21; uniconazoIe treatment in-creased significantIy IAA, ZR and ABA contents of Jihei 1 compared with Jishu 21. [Conclusion] Drought-toIerant sweetpotato cuItivar Jishu 21 exhibits high pIasma membrane integrity and root vitality by increasing activities of antioxidant enzymes under drought stress and malntalning high contents of IAA, ZR and ABA. Unicona-zoIe exerts greater reguIatory effects on physioIogical and biochemical properties of drought-sensitive sweetpotato cuItivar Jihei 1 under drought stress.

Distribution Characteristics Comparison of Salix Psammophila Roots under Different Landforms in Mu Us Desert

[Objective] In order to study plant adaptation mechanism under different landforms in drought regions.[Method] Observe soil moisture dynamic of Salix psammophila sample areas on the dune and depression with neutron moisture gauge and research the roots distribution of Salix psammophila sample areas on the dune and depression respectively by digging method.[Result] The quantity of Salix psammophila roots on the dune exponentially decreases while that on the depression decreases by power function in horizontal direction.In vertical direction,Salix psammophila roots on the dune are mainly distributed in 0-30 and 80-120 cm layers as 72% of all,while Salix psammophila roots on the depression are mainly distributed in 0-40 cm layers as 54% of all.[Conclusion] Salix psammophila roots on the dune not only use surface soil water but also use middle-layer groundwater.Salix psammophila roots on the depression primarily use surface soil water.

THE ROOTS AND FRUITS OF CHINESE SPRING FESTIVAL

Traditional festivals forge a nation’s cultural identity and solidarity.Through opulent customs and celebratory activities,they convey the collective psyche,emotions,and aspirations of a nation.As a key part of Chinese culture,traditional Chinese festivals reinforce the bond among Chinese people and preserve our cultural roots.Of all Chinese festivals,the Spring Festival is the most important,both culturally and historically.

Effects of Salt Stress on the Activity and the Amount of Tonoplast H^+-ATPase from Pea Roots

To study the function and adaptive mechanism of tonoplast H + ATPase under salt stress, pea ( Pisum sativum L.) seedlings were treated with different concentrations of salt (100-250 mmol/L NaCl) and with 100 mmol/L NaCl for different days (1-3 d). The ATP hydrolytic activity and the proton transport activity and the changes of the amount of tonoplast H + ATPase (subunit A) were measured. ATP hydrolytic activity of H + ATPase prepared from plants treated with 250 mmol/L NaCl was reduced by about 25% compared to that of control plants, but that of stressed plants treated with 100 mmol/L and 200 mmol/L NaCl was unchanged. The activity from plants treated with 100 mmol/L NaCl for up to 3 d was lower than that of control plants by 20%. But the proton transport activity was increased under the same salt stresses as above. These results showed that the changes of the hydrolytic activity and the proton transport activity were not in proportion and salt stress may cause the change of the coupling ratio of H + transport activity to ATP hydrolysis. The protein amount kept unchanged and reduced a little only when pea was treated with 100 mmol/L NaCl for 3 d. These results indicated that salinity stimulated the increase of the pump efficiency of the V_ATPase from pea roots, which was due to the change of the coupling ratio, but not due to the increase of ATP hydrolysis and the amount of V_ATPase.

Effects of grassland vegetation roots on soil infiltration rate in Xiazangtan super large scale landslide distribution area in the upper reaches of the Yellow River,China

In order to study the infiltration characteristics of grassland soil in the super large scale landslides distribution area in the upper reaches of the Yellow River,this study selected the Xiazangtan super large scale distribution area in Jianzha County as the study area.Through experiments and numerical simulations,plant roots characteristics,soil physical properties and infiltration characteristics of naturally grazed grassland and enclosed grassland with different slope directions were compared and analyzed,and the influence of rainfall on seepage field and stability of the two grassland slopes were discussed.The results show that the highest soil moisture infiltration capacity(FIR)is found on the shady slope of the enclosed grassland(2.25),followed by the sunny slope of the enclosed grassland(1.23)and the shady slope of the naturally grazed grassland(-0.87).Correlation analysis show that soil water content,root dry weight density,total soil porosity,number of forks and root length are positively correlated with infiltration rate(P<0.05),whereas soil dry density is negatively correlated with infiltration rate(P<0.05).The results of stepwise regression analyses show that soil water content,total soil porosity,root length and number of forks are the main factors affecting soil infiltration capacity.And the ability of roots to increase soil infiltration by improving soil properties is higher than the effect of roots itself.After 60 min of simulated rainfall,the safety factors of the shady slopes of naturally grazed grassland and enclosed grassland are reduced by 29.56%and 19.63%,respectively,comparing to those before rainfall.Therefore,in this study,the roots play a crucial role in regulating soil infiltration and enhance slope stability by increasing soil water content,soil total porosity and shear strength while decreasing soil dry density.The results of this study provide theoretical evidence and practical guidance for the effective prevention and control of secondary geological disasters such as soil erosion and shallow landslide on the slope of river banks in the study area by using plant ecological measures.

Regulation of the growth of sprouting roots of black locust seedlings using root barrier panels

How can we regulate an invasive alien species of high commercial value?Black locust(Robinia pseudoacacia L.)has a unique capacity for seed dispersal and high germination.Field surveys indicate that black locust increases its growing area with sprouting roots and the elongation of horizontal roots at a soil depth of 10 cm.Therefore,a method to regulate the development of horizontal roots could be eff ective in slowing the invasiveness of black locust.In this study,root barrier panels were tested to inhibit the growth of horizontal roots.Since it is labor intensive to observe the growth of roots in the fi eld,it was investigated in a nursery setting.The decrease in secondary fl ush,an increase in yellowed leafl ets,and the height in the seedlings were measured.Installing root barrier panels to a depth of 30 cm eff ectively inhibit the growth of horizontal roots of young black locust.

Effects of Ag-carrying Zirconium Phosphate on the Kinetics of Growth of the Roots of Culture Artemisia annua

在植物组织和细胞培养过程中 ,尤其是在生物反应器培养中的染菌问题 ,一直是制约植物细胞培养工业化的难题。通过比较各种防腐剂的抑菌效果 ,确定银型磷酸锆盐抗菌粉为青蒿根培养的最佳防腐剂。银型磷酸锆盐抗菌粉在浓度为 30mg/L时 ,既能降低培养液的染菌几率 ,又不明显抑制青蒿根的生长及青蒿素的生物合成。在添加 30mg/L抗菌粉的培养液中进行的青蒿根生长、pH值变化以及残糖、铵离子和硝酸根离子消耗的动力学研究表明 ,在 4 0d内青蒿根在培养液中生长良好 ,营养成分的消耗和对照呈相似的趋势。

Studies on the Secretion of Organic Acids from Roots of Two-year-old Larix olgensis under Nutrient and Water Stress

[Objective] This study aimed to investigate the effects of nutrient and water stress on the secretion of organic acids from roots of two-year-old Larix olgensis. [Method] Different nutrient and water stress conditions were designed to investi- gate the types and quantities of organic acids secreted from roots of two-year-old L. olgensis. [Result] Under nutrient and water stress, the types of organic acids secreted from roots of two-year-old L. olgensis increased, which varied with different stress levels. In addition, nutrient and water stress also increased the secretory vol- ume of organic acids from roots of two-year-old L. olgensis. The increment in total amount of organic acids reached the maximum under Level 1 （high stress）. Among different types of organic acids, the increment in secretory volume of citric acid reached the maximum, followed by malic acid, while oxalic acid presented relatively small increment. Furthermore, the increment in secretory volume of these three organic acids all reached the maximum under Level 1. [Conclusion] The proportion of the secretory volume of each organic acid accounting for the total amount of organic acids varied slightly, but the overall order was unchanged.

Impact of Inulin Extracted, Purified from (Chicory and Globe Artichoke) Roots and the Combination with Maltodextrin as Prebiotic Dietary Fiber on the Functional Properties of Stirred Bio-Yogurt

Inulin is a prebiotic dietary fiber that plays an integral role in producing functional dairy products with improved health benefits. Therefore, the objectives of this study are as follows: extract and purify inulin from chicory roots and globe artichoke roots;evaluate the physicochemical, functional properties and functional groups of the purified inulin;determine the functional properties of chicory roots inulin-maltodextrin and globe artichoke roots inulin-maltodextrin and compare it with that of the commercial inulin;examine the impact of various inulin on physiochemical, microstructural, textural, sensory characteristics and as prebiotic dietary fiber on probiotic bacteria’s viability of stirred bio-yogurt. The characteristics of the microstructure were investigated by scanning electron microscopy and, Fourier transforms infrared spectroscopy to detect the functional group. The resulting inulin exhibited a high yield and purity along with enhanced functional properties. Stirred bio-yogurt fortified with chicory roots inulin or globe artichoke roots inulin showed enhanced physicochemical, microstructural, microbiological, and overall sensorial acceptability followed by chicory roots inulin-maltodextrin or globe artichoke roots inulin-maltodextrin and the commercial inulin as compared to the control. Stirred bio-yogurt samples can offer various health benefits and wide applications as supplement of prebiotic dietary fiber in dairy industry.

ROOTS比对法气体流量计检定装置运行分析

介绍了ROOTS比对法LL-1600型检定装置的工作原理和主要特点,通过在线检定和运行分析,该装置在满足不同气体流量计检定要求的条件下,具有性能可靠稳定、数据处理误差小、实用性强、操作简便等优点,适用于石油行业中多种气体流量计的检定和测试。