Anti-Melanogenesis Activity of Supercritical Carbon Dioxide Extract from Perilla frutescens Seeds

Perilla frutescens seed (PFS) oil is reported to inhibit skin photoaging;however, its effect on melanogenesis has not yet been investigated. Herein, we tested the anti-melanogenesis activity of an oil-based extract from PFS with supercritical carbon dioxide (scCO2). In a cell culture system, B16 mouse melanoma cells were treated with the PFS scCO2 extract and other samples. The PFS scCO2 extract decreased melanin production by approximately 90% in B16 mouse melanoma cells without cytotoxicity at 100 μg/mL. This effect was greater than that of the well-known melanogenesis inhibitor, kojic acid. Although a hexane-extracted PFS oil and a squeezed PFS oil also decreased melanin production in the B16 cells, the inhibitory effect of the PFS scCO2 extract was higher than both of these. Chemical analysis of the PFS scCO2 extract and squeezed PFS oil showed that almost 90% of the components of both oils were α-linolenic acid, linoleic acid, and oleic acid. Furthermore, the ratio of those three fatty acids across both samples was almost the same. When the three fatty acids were mixed in the same ratio as in the PFS scCO2 extract, the IC50 of the mixture for melanin production in B16 melanoma cells was identical to that of the PFS scCO2 extract. However, the IC50 of the squeezed PFS oil was approximately 6.6 times higher than that of the mixture. Although those fatty acids are the main inhibitory ingredients against melanin production in all of the extracts, some factor(s) in the squeezed PFS reduce their affinity with the cells. These results indicated that the PFS scCO2 extract could be a superior melanogenesis inhibitor. Although its main ingredients are probably the same as those of the squeezed PFS oil, it is necessary to extract with scCO2 for stronger anti-melanogenesis activity.

Studies on In Vitro Flowering and Fruiting of Perilla frutescens

Influences of PGR, sucrose, and ammonium nitrate on in vitro flowering and fruiting from cotyledon explants of P. frutescens were studied. The regenerated shoots at 2-4. cm from cotyledon explants on MS medium supplemented with 0.5 mg L^-1 BA and 1.0 mg L^-1IAA were excised and transferred to MS medium containing 30 g L^-1 sucrose, 8.25 g L^-1 ammonium nitrate, and 1.0 mg L^-1 BA. Following 40 d of culture, 86.2% of them flowered and set seeds. These seeds were germinable and developed into flowering plants in the fields. This study provides a simple system for rapid breeding of P. frutescens and studying the physiological mechanism of flowering of plants.

GC-MS analysis of volatile compounds of Perilla frutescens Britton var. Japonica accessions: morphological and seasonal variability

Objective: To investigate the composition of volatile compounds in the different accessions of Perilla frutescens(P. frutescens) collected from various habitats of China and Japan. Methods: In the present study, the essential oil from the leaves of P. frutescens cultivars from China and Japan was extracted by hydro-distillation and the chemical composition and concentration of the volatile components present in the oils were determined by gas chromatography–mass spectrometry(GC–MS) analysis. Results: Among the volatile components, the major proportion was of perilla ketone, which was followed by elemicin and beta-caryophyllene in the Chinese Perilla cultivars. The main component in the oil extracted from the Japanese accessions was myristicin, which was followed by perilla ketone and beta-caryophyllene. We could distinguish seven chemotypes, namely the perilla ketone(PK) type, perilla ketone, myristicin(PM) type, perilla ketone, unknown(PU) type, perilla ketone, beta-caryophyllene, myristicine(PB) type, perilla ketone, myristicin, unknown(PMU) type, perilla ketone, elemicine, myristicin, beta-caryophyllene(PEMB) type, and the perilla ketone, limonene, betacryophyllene, myristicin(L) type. Most of the accessions possessed higher essential oil content before the flowering time than at the flowering stage. The average plant height, leaf length, leaf width of the Chinese accessions was higher than those of the Japanese accessions. Conclusion:The results revealed that the harvest time and geographical origin caused polymorphisms in the essential oil composition and morphological traits in the Perilla accessions originating from China and Japan. Therefore, these chemotypes with desirable characters might be useful for industrial exploitation and for determining the harvest time.

Effects of Plant Density on the Economic Yield and Agronomic Characters of Perilla frutescens L.

Perilla frutescens L. is a traditional medicinal plant in china. In recent years, with more and more attention is paid to the nutritional and health values of Perilla frutescens L, it has become a potential medicinal and edible crop. Two Per- ilia frutescens cultivars, Qisu No.1 （oil type） and Qisu No.3 （leaf and seed-using type）, bred by Rapeseed Research Institute of Guizhou Academy of Agricultural Sciences, were used as test material for studying the effects of different planting density on the economic yield and agronomic characters of Perilla frutescens L. under moderate fertility level. The results showed the variation tendency of agro- nomic characters with the change of planting density was similar for the two Perilla frutescens cultivars. Among them, the plant height, main-stem nods, first effective branch length, first effective branch height, spikes per plant, and yield per plant were negatively related to the planting density; and main spike length and main- spike grains were positively related to the planting density. The effects of planting density on kilo-grain weight were not significant. The yield of the two cuitivars all increased first and then decreased with the increase of planting density. The re- gression analysis of planting density versus yield of Perilla frutescens L. was per- formed for obtaining the regression equations （Qisu No.l： y=54.046 5＋96.777 lx- 45.719 8x2, r=0.999 4; Qisu No.3：y=38.717 6＋42.111 3x-16.757 7x2, r=0.999 8）. Based on the regression equations, the optimal planting density for Qisu No.1 was 158 745 plants/hm2 with peak yield of 1 578.90 kg/hm2, and for Qisu No.3 was 188 745 plants/hm2 with peak yield of 977.55 kg/hm2. Under the optimal planting density, Qisu No.3 could also harvest 3 000 kg/hm2 of Perilla frutescens dry leaves and 2 400 kg/hm2 of Perilla frutescens stems. This research would provide an important reference for the promotion, high-yield cultivation and comprehensive utilization of Perilla frutescens L.

Thai Perilla frutescens fruit oil alleviates carbon tetrachloride-induced hepatotoxicities in rats

Objective:To study the effect of perilla fruit oil against carbon tetrachloride(CCl4)-induced liver damage in rats.Methods:Perilla fruit oil was analyzed in terms of fatty acids,tocopherols and tocotrienols using chromatography.Sub-chronic toxicity of perilla fruit oil was investigated in rats for 90 d followed by a 28 d recovery period.Hematological,biochemical and pathological parameters were determined.To evaluate hepatoprotection,rats were divided into five groups and orally administered with Tween 80 for 10 d;Tween 80,silymarin,perilla fruit oil(0.1 mL/200 g)and perilla fruit oil(1 mL/200 g)for 10 d together with subcutaneous injection of CCl4(2 mL/200 g)on days 9 and 10.Liver enzymes and pathological parameters were determined.Results:Perilla fruit oil containedα-linolenic acid(56.55%of total fatty acid),β-tocopherol(49.50 mg/kg)andγ-tocotrienol(43.65 mg/kg).Rats showed significant changes in the percentage of monocytes and platelet indices following perilla fruit oil consumption for 90 d;in the percentage of neutrophils and lymphocytes,and RBC indices in the recovery period when compared with the deionized water group.Total protein and creatinine levels were increased while alkaline phosphatase and aspartate aminotransferase levels were decreased(P<0.05).Organ weight index and pathological indicators did not change significantly.The liver of CCl4-induced rats showed remarkable centrilobular fatty changes,which was ameliorated by perilla fruit oil pretreatment.Aspartate aminotransferase,alanine aminotransferase and alkaline phosphatase levels were decreased(P<0.05)in rats given perilla fruit oil.Conclusions:Perilla fruit oil is rich inα-linolenic acid,β-tocopherol andγ-tocotrienol and improves blood biomarker levels and protects against CCl4-induced hepatotoxicity.Further studies are required before supporting its use for the treatment of hepatitis.

紫苏(Perilla frutescens)的种籽、茎叶营养

紫苏(Perilla frutescens)原产我国,至今已有2千多年的栽培历史,历来享有食疗同源珍品之称。本研究结果表明,其种籽蛋白质、脂肪等,以及活性营养素(β-Carotene、V_(B1)、V_(B2)、V_C、V_E)、矿物元素(Ca、P、Fe、Zn……)及油脂、脂肪酸(C_(16:0)、C_(18:0)、C_(18:1)、C_(18:1)、C_(18:3)……)含量均十分显著,尤其是它的β-胡萝卜素(β-Carotene)成倍高于红胡萝卜、番茄、红苋等蔬菜。

Development and Characterization of New Microsatellite Markers for <i>Perilla frutescens</i>(L.) Britton

Based on RNA sequences using transcriptome analysis, 37 new simple sequence repeat (SSR) primer sets were developed for Perilla species. These new SSR markers were applied to analyze the genetic diversity among 15 accessions of Perilla species. A total of 182 alleles were confirmed in 37 loci, with an average of 4.9 alleles per locus and from 2 to 9 alleles per locus. The MAF (major allele frequency) per locus varied from 0.200 to 0.733, with an average of 0.463. The gene diversity (GD) ranged from 0.391 to 0.853, with an average of 0.670. The average polymorphic information content (PIC) was 0.624, ranging from 0.315 to 0.838. The new SSR markers of Perilla species reported in this study may provide potential markers to analyze the genetic diversity and genetic relationships of Perilla species. In addition, new Perilla SSR markers developed from transcriptome analysis can be useful for the identification of cultivars, conservation of Perilla germplasm resources, and genetic mapping and designating of important genes/QTLs for future Perilla crop breeding programs.

紫苏花蚬子香菇复合保健风味酱的研制

以紫苏叶、花蚬子、香菇、黄豆酱为主要原料,开发一种紫苏海鲜复合保健风味酱。在单因素试验的基础上,通过响应面试验结合感官评定法确定了紫苏花蚬子香菇复合保健风味酱的最佳制备工艺条件:蚬子肉烘干时间为60 min,辣椒片添加量为27.8 g,蚬子肉添加量为222.7 g,紫苏叶添加量为31.4 g,香菇添加量为180 g。并对产品进行了理化指标和微生物指标检测,结果均符合相关标准。研究开发的紫苏花蚬子香菇复合保健风味酱味道独特、营养丰富,不仅提高了紫苏、花蚬子的经济附加值,而且满足了人们对复合功能酱产品的需求,为今后开发复合功能酱产品提供了参考依据。

单菌剂固态发酵改善紫苏饼粕工艺优化及理化特性分析

目的通过单菌剂固态发酵工艺优化改善紫苏饼粕品质。方法以紫苏饼粕为原料,研究枯草芽孢杆菌(Bacillus subtilis JP2)接种量、发酵时间、发酵温度、面粉添加比例对发酵紫苏饼粕的品质影响,并通过正交实验优化发酵工艺,并对最佳发酵工艺条件下发酵的紫苏饼粕的主要成分、pH及游离氨基酸含量进行测定。结果正交实验极差分析和验证实验显示,最佳发酵条件为:发酵时间60 h、发酵温度34℃、接种量2.5%和面粉添加比例1:20(g/g)。在最佳发酵条件下,发酵紫苏饼粕中蛋白酶活力为1152 U/g,氨基酸态氮含量为0.49 g/100 g;水分含量和pH分别由58.11%、6.27增加至60.20%、8.09,蛋白质、脂肪、还原糖含量分别由32.14%、11.10%、0.47%降低至24.92%、2.66%、0.05%,游离氨基酸种类增加至13种,总氨基酸含量、必需氨基酸含量分别增加至1.1455%、0.8031%。结论经优化获得了单菌剂固态发酵紫苏饼粕工艺的最佳工艺条件,该工艺条件有效改善了紫苏饼粕的品质。

紫苏中紫苏醛含量的高光谱预测方法

为了实现高光谱成像技术快速检测紫苏中的紫苏醛(PAE)含量,采集了4种产地的紫苏高光谱图像,在获取紫苏有效波长图像的基础上,将其纹理特征和经小波变换后获得的能量值与光谱值采用不同方式融合,构建出了不同的表征向量,建立了相应的PAE含量快速检测模型。经对比分析确定了PAE含量最优预测策略,具体方法如下。(1)采用4种方法对光谱值进行预处理,对比所构建模型的预测能力,可得较优预处理方法为局部加权回归散点平滑(LOWESS)。(2)运用竞争自适应重加权采样法(CARS)和连续投影算法(SPA)提取预处理后光谱信息的特征波长,计算对应的光谱值,以便与其他特征进行组合。(3)对高光谱图像进行主成分分析(PCA)获得有效波长图像,利用其灰度共生矩阵(GLCM)提取能量(ASM)、对比度(CON)、相关性(COR)和熵(ENT)等4种纹理特征;同时,采用Daubechies小波对有效波长图像进行三层分解,将分解出的低频分量能量也作为有效波长图像的1种表征特征。(4)将上述提取的特征波长光谱值、小波能量值、纹理特征值以不同组合方式构造特征输入向量,在此前提下分别构建偏最小二乘回归(PLSR)、BP神经网络、随机森林(RF)、极限梯度提升树(XGBoost)四种检测模型,经对比分析后获得最优输入向量和预测模型。结果表明,基于单类特征输入向量的4种预测模型的预测能力均不如多类特征融合的输入向量;最佳输入向量是经LOWESS预处理后由CARS优选的特征波长所对应的光谱值与有效波长图像的纹理特征值和小波能量值三者的融合向量,且XGBoost模型预测能力最强,其训练集R_(c)^(2)和RMSEC分别为0.99808和0.02249,测试集R_(p)^(2)和RMSEP分别为0.98944和0.03640。该成果为快速检测紫苏中PAE含量提供了一种新手段,也为其他成分检测策略的制定提供了参考。

干燥方式对紫苏叶品质的影响

为评价不同干燥方式对紫苏叶品质的影响,采用热泵干燥(heat pump drying,HPD)、远红外干燥(far-infrared drying,FIRD)、真空冷冻干燥(vacuum freeze drying,VFD)、热风干燥(hot air drying,HAD)4种干燥方式对紫苏叶进行处理,测定其基本营养成分含量、活性成分含量及抗氧化能力,并利用隶属函数法进行综合评价,采用顶空固相微萃取-气质联用技术鉴定其挥发性物质。结果表明,VFD处理的紫苏叶中蛋白质、粗脂肪、黄酮、多酚、迷迭香酸含量最高,色差值最小,DPPH、ABTS~+自由基清除能力最强;HPD处理的紫苏叶中还原糖含量最高;经4种干燥方式处理后,紫苏叶中挥发性物质的种类与相对含量都有不同程度的增减,烯烃类和醛类为主要挥发性物质。综合评价表明,VFD处理的紫苏叶品质优于其他干燥处理,但能耗较高;HPD处理的紫苏叶品质优于HAD和FIRD,是紫苏叶干燥处理的一种较好选择。

不同产地紫苏种子萌发对温度和pH的耐性评估

以13份紫苏种质资源为试材,采用培养皿发芽的方法进行萌发试验,设置不同处理研究温度、pH等条件对13份紫苏种子萌发特性的影响,结合隶属函数分析法对其耐性进行综合评价,以期为高产、高抗逆型紫苏优良种质资源的选育提供参考依据。结果表明:13个产地紫苏种子的萌发最适温度范围为15~25℃,pH范围为4~8;隶属函数分析表明,山东日照、黑龙江佳木斯、甘肃庆阳对温度耐受性较强,黑龙江佳木斯、江苏盐城、甘肃庆阳、河北沧州青县(CZ1、CZ2)对pH的耐受性较强。综上,黑龙江佳木斯、甘肃庆阳、江苏盐城等产地对温度及pH的耐受性较强。

紫苏磷脂酸磷酸水解酶基因(PfPAH1)的鉴定及功能分析

本文基于紫苏基因组数据筛选获得两条PfPAH1基因序列,分别命名为PfPAH1-1和PfPAH1-2。应用生物信息学工具分析PfPAH1s蛋白理化性质、功能结构域及系统进化。定量PCR(qRT-PCR)检测PfPAH1s在紫苏根、茎、叶、花及不同发育时期种子的表达谱。进一步克隆到高表达的PfPAH1-1基因的编码序列并进行烟草瞬时转化以鉴定其功能。结果表明,PfPAH1-1和PfPAH1-2基因的开放阅读框(ORF)长度均为2715 bp,编码904个氨基酸残基,含有Lipin_N、Lipin_mid和属于HAD_like超家族的LNS2三个保守结构域。系统进化分析显示紫苏PfPAH1-1蛋白与唇形科植物一串红的SsPAH1亲缘关系最近,其次是葡萄和芥菜。PfPAH1-2蛋白则与唇形科的芝麻SiPAH1亲缘关系最近,其次为油橄榄,紫苏和芝麻均为油料作物,推测PfPAH1-2和SiPAH1可能具有相似功能。qRT-PCR分析表明PfPAH1-1和PfPAH1-2基因均在开花后40 d种子中表达量最高,预示着其可能参与油脂合成积累。烟草瞬时转化揭示过表达PfPAH1-1基因烟草叶片总脂肪酸及中性脂含量均高于野生型烟草,然而磷脂含量降低。

紫苏磷脂酰乙醇胺结合蛋白基因家族成员PfFT3调控开花功能

紫苏(Perilla frutescens)含有丰富的生物活性物质和营养成分,是严格的短日照植物。目前,对紫苏的研究主要集中在产量和脂肪酸积累等农艺性状,而对紫苏开花进程及花器官形成的研究较少,其分子调控机制尚不明确。FLOWERING LOUC T(FT)是目前公认的感知光周期的关键基因,在花转变中发挥重要作用。PfFT3是FT-like亚家族基因,其在植物开花调控的功能尚待揭示。本研究首先通过亚细胞定位证明PfFT3定位于细胞核和细胞质。之后构建植物表达载体pCAMBIAI1303-PfFT3,并通过农杆菌介导的花序浸染法转化野生型Col-0和突变体fd-2、fd-3和ft-10拟南芥,以此分别获得稳定遗传的纯合的过表达和回补转基因株系。结果分析表明,PfFT3的过表达能够显著促进拟南芥开花并且能够挽救突变体fd-2、fd-3和ft-10的晚花表型,进一步研究表明,外源PfFT3基因的表达促进下游内源开花基因AtSOC1、AtAP1、AtFUL和AtLFY的表达。综上所述,本研究阐明了PfFT3在促进开花过程的积极作用,为深入研究PfPEBP基因的功能及紫苏短日照早花优良种质培育奠定基础。

不同品种紫苏汁的生物活性成分及抗氧化性研究

紫苏是一种药食同源的草本植物,具有预防疾病、调节食物风味的功能。文章采用新鲜紫苏叶片的汁液进行活性物质含量及抗氧化能力的测定,并进行相关性分析。结果表明,各品种紫苏汁的生物活性成分丰富且差异显著,含有抗坏血酸(2.08~4.23 mg/100 mL)、总黄酮(1.89~20.86 mg/mL)、总多酚(1.62~7.75 mg/mL)、总多糖(5.74~34.95 mg/mL)、总花青素(18.56~199.50 mg/L)等。相关性分析表明,黄酮、多酚在紫苏汁发挥抗氧化性方面起着关键作用,清除DPPH自由基、ABTS自由基的效果较好,其含量与清除DPPH自由基、ABTS自由基的IC 50值间存在极显著负相关(P<0.001),但与清除羟基自由基的IC 50值呈非常显著正相关(P<0.01)。相比于黄酮、多酚,紫苏汁中抗坏血酸含量较低,在该实验中与抗氧化性无显著相关性。综合比较,双面紫苏冀-S品种可作为开发功能性紫苏调味品的良好来源。

紫苏AP2基因家族PfWRI1促进植物种子油脂积累

AP2转录因子属于AP2/ERF超家族,参与调节植物生长发育的各种生物学过程,以及对生物和非生物胁迫的响应。然而,关于紫苏(Perilla frutescens) AP2转录因子家族的研究未见报道。在本研究中,从紫苏基因组中鉴定到18个AP2家族成员,使用生物信息学方法分析了基因结构、保守基序和顺式作用元件。WRINKLED1 (WRI1)是许多植物物种中脂质生物合成的关键调节因子,在油脂合成过程中发挥重要调控作用。通过序列比对发现其中1个成员与AtWRI1序列高度同源,含有2个保守的AP2结构域,命名为PfWRI1。结合转录物组数据分析了PfAP2家族基因在紫苏不同组织和种子发育不同阶段的表达水平,结果表明,PfWRI1仅在紫苏种子中高表达,暗示PfWRI1可能与种子的发育过程有关。进而构建植物过表达载体pCAMBIA1303-PfWRI1,通过农杆菌侵染技术转化野生型(Col)以及突变体(wri1-1)拟南芥,分别获得过表达和回补株系。结果表明,相比于Col,PfWRI1的表达导致拟南芥种子含油率提高了8.90%~13.57%,并促进转基因拟南芥种子中油酸(C18:1)和亚油酸(18:2)的积累,减少棕榈酸(C16:0)、花生酸(C20:0)和花生一烯酸(C20:1)的积累。此外,外源PfWRI1基因的表达增加了糖酵解和脂肪酸生物合成相关基因AtPKP-α、AtPKP-β1、AtBCCP2、AtSUS2和AtLIP1的表达。综上所述,PfWRI1可能通过与上述基因互作,增加不饱和脂肪酸含量来促进油脂积累。

广西药食两用紫苏高产栽培技术

紫苏是我国药食两用作物之一,药用和食用价值高。近几年,广西紫苏产业发展迅速,对新品种、新技术需求迫切。从品种选择、整地、田间管理、病虫害防治及采收等方面总结了广西药食两用紫苏高产栽培技术,以期为广西紫苏产业发展提供技术支撑。

基于网络药理学和UPLC指纹图谱的紫苏质量标志物(Q-Marker)预测

基于UPLC指纹图谱和网络药理学法分析并筛选紫苏潜在质量标志物(Q-Marker)。首先建立15批紫苏叶及14批紫苏梗的指纹图谱,并对不同来源、批次的紫苏叶和紫苏梗中的成分及含量进行比较,标定紫苏不同部位指纹图谱的共有峰和非共有峰;采用网络药理学法构建紫苏“成分-靶点”网络图,并构建靶点蛋白互作网络图,预测紫苏Q-Marker。本研究建立的紫苏不同部位的指纹图谱,共检测到了5种成分,其中迷迭香酸、咖啡酸、木犀草素-7-O-葡萄糖醛酸苷、木犀草素-7-O-二葡萄糖醛酸苷为叶和梗的共有成分,芹菜素-7-O-葡萄糖醛酸苷为紫苏叶特有成分。筛选得到包括MAPK1、PIK3CA等在内的14个核心靶点,对以上靶点进行GO和KEGG功能分析可知涉及肿瘤坏死因子、新冠肺炎、脂质和动脉粥样硬化等通路,最后构建“成分-靶点-通路”网络图,选取排名前4的靶蛋白与4个成分进行分子对接验证,结果显示成分与蛋白之间具有十分良好的结合性能。本实验基于UPLC法建立紫苏不同部位多成分含量测定方法,此方法操作简单、准确度高,可作为紫苏质量检测的参考方法;同时结合网络药理学和分子对接技术预测迷迭香酸、咖啡酸、木犀草素-7-O-葡萄糖醛酸苷、木犀草素-7-O-二葡萄糖醛酸苷为紫苏潜在质量标志物,以此来评价紫苏“多成分-多靶点-多通路”的协同作用,为紫苏的质量控制提供了理论依据,同时也为后续的紫苏药效物质基础和作用机制提供坚实的基础。

北京延庆山区紫苏林下生态种植模式研究

【目的】探明北京山区老龄化村庄中药材林下生态种植模式,助力乡村振兴。【方法】以典型的老龄化村庄—延庆区大庄科乡黄土梁村作为试验地点,中药材紫苏作为试验材料,在板栗林下进行生态种植,设置不同的播种量和有机菌肥用量,收获后统计分析紫苏产量、品质及收益,与大田和四旁地种植的紫苏进行比较。采用水蒸气蒸馏法提取紫苏叶挥发油并测定含量,使用高效液相色谱法测定紫苏梗和紫苏子中迷迭香酸含量。【结果】采用生态种植技术,紫苏药材品质达到且优于《中国药典》2020版标准;不同种植环境的收益达9 585.00~10 350.00元/hm^(2);郁闭度为0.20板栗林下,播种量22.50 kg/hm^(2),有机菌施肥量1 800.00 kg/hm^(2)的条件下紫苏药材产量高、品质优、收益好。【结论】紫苏林下生态种植模式充分利用山区农村的自然禀赋,在获得可观收益的同时,大幅度降低了劳动力投入,非常适合在山区老龄化农村进行推广。

外源添加苯甲酸对紫苏种子发芽和幼苗生长的影响

为探究外源苯甲酸胁迫对紫苏种子萌发、幼苗生长及叶片抗氧化酶活性的影响,添加苯甲酸对紫苏种子进行培养皿滤纸培养和室内盆栽实验,设置0、1、1.5、2、2.5、3 mmol/L 6个梯度处理,研究不同浓度苯甲酸胁迫对紫苏种子发芽率、发芽势、发芽指数、活力指数、紫苏幼苗生长以及抗氧化酶活性的影响。结果表明,随着苯甲酸浓度的增加,紫苏种子的发芽率、发芽势、发芽指数、活力指数总体表现为低浓度促进、高浓度抑制;紫苏幼苗的根重、胚根长、胚轴长和株鲜重均呈显著下降趋势,幼苗叶片过氧化氢酶和过氧化物酶活性呈显著下降趋势(P<0.05),超氧化物歧化酶活性呈先升高后下降趋势,在1.5 mmol/L达到最大。外源添加苯甲酸对紫苏种子萌发与苯甲酸浓度有关(低浓度促进高浓度抑制),对紫苏幼苗的生长具有抑制作用,证实了苯甲酸对紫苏的生长存在自毒作用。