Effects of β-Amino Butyric Acid Induced Rice Blast Resistance on Reactive Oxygen Metabolism

[Objective] This study was to understand the effects of β-Amino butyric acid(abbreviated as BABA) induced rice blast resistance on reactive oxygen metabolism. [Method] Using the cultivar Chaochan 2 that is highly susceptible to disease as experimental material, the changes of catalase(CAT), and superoxide dismutase(SOD) and MDA activities in rice treated by BABA were investigated. [Result] In rice plants treated by BABA, the activities of CAT and SOD increased, meanwhile the MDA content also rose to some extent, resulting in the disease resistance to rice blast. [Conclusion] By influencing reactive oxygen metabolism, BABA endows rice plants with resistance to rice blast. BABA is safe to environment and has highly resistance-inducing capacity, it could be generalized in production.

Induced Resistance of Tomato against Gray Mold (Botrytis cinerea) by Salicylic Acid (SA)

[ Objective ] The paper was to explore the induced resistance of tomato against gray mold （Botrytis cinerea） by salicylic acid. [ Method ] SA was used as an inducer to treat tomato seedlings, the effects of SA on mycelial diameter and spore germination of B. cinerea were studied, and the changes of 4 defense enzyme activities containing catalase （CAT）, peroxidase （POD）, polyphenol oxidase （PPO） and phenylalanine ammonia lyase （PAL）, as well as malondialdehyde （MDA） content during the production process of induced resistance were also measured. [ Result] SA had no inhibitory effect against spore germination and myce- lial growth of B. cinerea within the concentration range, and the relative induced effect had different degrees of improvement after treatment. The induced effect was the best as B. cinerea was challenged to inoculate at the third day after using 150 mg/L SA in tomato plants, and the duration of resistance was 10 -15 d. After treated by SA, CAT, POD, PPO and PAL first increased and then decreased in systemic induced resistance against B. cinerea, which were significantly higher than control. Meanwhile, MDA content showed ascendant trend in wavy line form. [ Conclusion ] The use of SA within a certain concentration range is safe; CAT, POD, PPO and PAL activities have positive correlation with induced resistance against B. cinerea, the increase of MDA content also has close relationship with the imvrovement of disease resistance.

Induced systemic resistance to Meloidogyne spp by <i>β</i>,amino butyric acid in tomato

β,amino butyric acid (BABA) induced resistance against?Meloigogyne?spp in tomato. Significantly (p?= 0.05) less, 41.11 second stage juveniles (J2) enter the roots of treated than, 116.66 J2 in untreated control plants. Root fresh and dry weight (Rfw, Rdw) were 2.87 and 0.12 g in treated compared with 4.78 and 0.30 g in nematode infected control plants respectively, 30 d after nematode inoculation. Sfw and Sdw were 8.62 and 0.60 g compared with 3.94 and 0.22 g in control plants. Foliage spray at 40 and 20 mM of BABA was more effective than 10 and 5 mM treatments. The former two concentrations recorded the lowest, average gall index, 2.11 compared with 3.33, 4.11, and 5 for the latter two concentrations and nematode infected control respectively. Results also indicated that treatments with BABA prior to nematode inoculation were superior in inducing resistance toMeloidogyne?spp over treatment at the time or after nematode inoculation.

A Triterpenoid Inhibited Hormone-Induced Adipocyte Differentiation and Alleviated Dexamethasone-Induced Insulin Resistance in 3T3-L1 adipocytes

6a-Hydroxylup-20(29)-en-3-on-28-oic acid(1),a natural triterpenoid,was found to possess the ability in a dose-dependent manner inhibiting hormone-induced adipocyte differentiation in 3T3-L1 preadipocytes,and restoring glucose consuming ability in dexamethasone(DXM)-induced insulin resistant 3T3-L1 adipocytes.Compound 1 was also found to ameliorate DXM-induced adipocyte dysfunction in lipolysis and adipokine secretion.Mechanistic studies revealed that 1 inhibited adipocyte differentiation in 3T3-L1 preadipocytes via down-regulating hormone-stimulated gene transcription of peroxisome proliferator-activated receptor c and CCAAT-enhancer-binding protein alpha which are key factors in lipogenesis,and restored DXM-impaired glucose consuming ability in differentiated 3T3-L1 adipocytes via repairing insulin signaling pathway and activating down-stream signaling transduction by phosphorylation of signaling molecules PI3K/p85,Akt2 and AS160,thus leading to increased translocation of glucose transporter type 4 and transportation of glucose.

A change of phenolic acids content in poplar leaves induced by methyl sali-cylate and methyl jasmonate

The contents of seven different phenolic acids such as gallic acid, catechinic acid, pyrocatechol, caffeic acid, coumaric acid, ferulic acid and benzoic acid in the poplar leaves （Populus Simonii×Populus Pyramibalis c.v and Populus deltoids） suffocated by Methyl jasmonate （MeJA） and Methyl salicylate （MeSA） were monitored for analyzing their functions in interplant communications by using high-pressure liquid chromatography （HPLC）.The results showed that the contents of phenolic acids had obviously difference in leaves exposed to either MeSA or MeJA.When P.deltoides leaves exposed to MeJA or MeSA, the level of gallic acid, coumaric acid, caffeic acid, ferulic acid and benzoic acid was increased, gallic acid in leaves treated with MeJA comes to a peak at 24 h while to a peak at 12-d having leaves treated with MeSA.When P.Simonii ×P.Pyramibalis c.v leaves were exposed to MeJA or MeSA, the level of gallic acid, pyrocatechol and ferulic acid was increased; The catechinic acid and benzoic acid had a little drop; The caffeic acid and coumaric acid were undetected in both suffocated and control leaves.This changed pattern indicated that MeJA and MeSA can act as airborne signals to induce defense response of plants.

Effects of Exogenous Salicylic Acid Derivative on the Resistance to TMV and Activity of Defense Enzymes of Tobacco

[Objective] This study aimed to evaluate the effects of exogenous salicylic acid derivatives on tobacco resistance to TMV and activity of defense enzymes. [Method] The tobboco leaves were treated by exogenous salicylic acid derivatives. Then, the disease occurrence was observed, and the activity of phenylalanin ammo- nia lyase （PAL） and peroxidase （POX） were measured. [Result] Exogenous salicylic acid derivative increased the activities of PAL and POX, while did not influence the resistance to TMV. [Conclusion] The result provides a theoretical basis for the study of plant disease resistance mechanisms.

Pathophysiology of insulin resistance and steatosis in patients with chronic viral hepatitis

Chronic hepatitis due to any cause leads to cirrhosis and end-stage liver disease.A growing body of literature has also shown that fatty liver due to overweight or obesity is a leading cause of cirrhosis.Due to the obesity epidemic,fatty liver is now a significant problem in clinical practice.Steatosis has an impact on the acceleration of liver damage in patients with chronic hepatitis due to other causes.An association between hepatitis C virus (HCV) infection,steatosis and the onset of insulin resistance has been reported.Insulin resistance is one of the leading factors for severe fibrosis in chronic HCV infections.Moreover,hyperinsulinemia has a deleterious effect on the management of chronic HCV.Response to therapy is increased by decreasing insulin resistance by weight loss or the use of thiazolidenediones or metformin.The underlying mechanisms of this complex interaction are not fully understood.A direct cytopathic effect of HCV has been suggested.The genomic structure of HCV (suggesting that some viral sequences are involved in the intracellular accumulation of triglycerides),lipid metabolism,the molecular links between the HCV core protein and lipid droplets (the core protein of HCV and its transcriptional regulatory function which induce a triglyceride accumulation in hepatocytes) and increased neolipogenesis and inhibited fatty acid degradation in mitochondria have been investigated.

Biochemical and Morphological Characteristics of Acid-Resistant Regenerants of Sugar Beet （Beta vulgaris L.）

The aim of the paper was to study the metabolite profile and morphological characteristics of sugar beet regenerants exposed to aluminium ions （Al^3＋）. The regenerants were selected basing on selective media with sublethal acidity （pH 3.5）. The thrice-repeated passaging of sugar beet microclones of two genotypes in low pH medium causes certain alterations in the cellular metabolism. The paper demonstrated that peroxidase （POD） and isocitrate lyase （ICL） activity increased in both varieties. At the same time, NADH-dehydrogenase （NADH-DH） activity decreased in hybrid plants. Glucose-6-phosphate-dehydrogenase （gl-6-ph-dh） activity increased in mail sterile （MS） hybrid plants, but reduced in Ramonskaya fertile （RF） hybrid plants. Adaptation to reduced pH was accompanied by alterations in the isozyme spectra of POD, 1- and 2-esterase, cytochrome c oxidase and malic enzyme （ME）. The adaptation process of sugar beet regenerants was also accompanied by an increase in protein synthesis. The level of metabolic response to stress very much depended on the initial genotype of the hybrid. In this experiment, aluminium resistant plants were growing rapidly in selective media. They developed leaves with healthy petioles and blades and had strong root systems.

Alternaria toxin-induced resistance in rose plants against rose aphid(Macrosiphum rosivorum): effect of tenuazonic acid

Many different types of toxins are produced by the fungus, Alternaria alternata （Fr.） Keissler. Little is known, however, regarding the influence of these toxins on insects. In this study, we investigated the toxin-induced inhibitory effects of the toxin produced by A. alternata on the rose aphid, Macrosiphum rosivorum, when the toxin was applied to leaves of the rose, Rosa chinensis. The results demonstrated that the purified crude toxin was non-harmful to rose plants and rose aphids, but had an intensive inhibitory effect on the multiplication of aphids. The inhibitory index against rose aphids reached 87.99% when rose plants were sprayed with the toxin solution at a low concentration. Further results from bioassays with aphids and high performance liquid chromatography （HPLC） analyses demon- strated that tenuazonic acid （TEA） was one of the most important resistance-related active components in the crude toxin. The content of TeA was 0.1199% in the crude toxin under the HPLC method. Similar to the crude toxin, the inhibitory index of pure TeA reached 83.60% 15 d after the rose plants were sprayed with pure TeA solution at the lower concentration of 0.060 IJg/ml, while the contents of residual TeA on the surface and in the inner portion of the rose plants were only 0.04 and 0.00 ng/g fresh weight of TeA-treated rose twigs, respectively, 7 d after the treatment. Our results show that TeA, an active component in the A. alternata toxin, can induce the indirect plant-mediated re- sponses in rose plants to intensively enhance the plant＇s resistances against rose aphids, and the results are very helpful to understand the plant-mediated interaction between fungi and insects on their shared host plants.

Changes in Unsaturated Levels of Fatty Acids in Thylakoid PSII Membrane Lipids During Chilling-induced Resistance in Rice

Temperature is one of the abiotic factors limiting growth and productivity of plants. In the present work, the effect of low non-freezing temperature, as an inducer of ＂chilling resistance＂, was studied in three cultivars of rice （Oryza sativa L.）, japonica cv. 9516 （j-9516）, the two parental lines of superhigh-yield hybrid rice between subspecies, Peiai/E32 （ji-PE）, and the traditional indica hybrid rice Shanyou 63 （i-SY63）. Leaves of chill-treated rice showed chilling-induced resistance, as an increase of their low-temperature tolerance was measured using chlorophyll fluorescence measurements, revealing a change in photosystem II （PSII） efficiency. After 5 d of exposure to 11 ~C under low light （100 pmol·m^-2·s^-1）, levels of unsaturated fatty acids in PSII thylakoid membrane lipids decreased during the initial 1-2 d, then increased slowly and reached 99.2%, 95.3% and 90.1% of the initial value （0 d） in j-9516, ji-PE and i-SY63, respectively, on the fifth day. However, under medium light （600 μmol·m^-2·s^-1）, all cultivars experienced similar substantial photoinhibition, which approached steady state levels after a decline in levels of unsaturated fatty acids in PSII thylakoid membrane lipids to about 57.1%, 53.8% and 44.5% of the initial values （0 d） in j-9516, ji-PE and i-SY63 on the fifth day. Under either chilling-induced resistance （the former） or low temperature photoinhibition （the latter） conditions, the changes of other physiological parameters such as D1 protein contents, electron transport activities of PSII （ETA）, Fv/Fm, xanthophyl cycle activities expressed by DES （deepoxide state） were consistent with that of levels of unsaturated fatty acids in PSII thylakoid membrane lipids. So there were negative correlations between saturated levels of fatty acids （16：1（3t）, 16：0, 18：0）, especially the 16：1（3t） fatty acid on thylakoid membrane and other physiological parameters, such as D1 protein contents, ETA and （A＋Z）/（A＋V＋Z）. A specific role of desaturation of fatty acids and the photoprotective pigments of the xanthophyl cycle, leading to an acclimation response in thylakoid membrane lipids may be involved. We conclude that chilling-induced resistance is accelerated by the unsaturation of thylakoid membranes, and the ability of rice plants to cold-harden can be enhanced by genetic engineering.

Different Proteomics of Ca^(2+) on SA-induced Resistance to Botrytis cinerea in Tomato

This study aims to comprehensively study the effects of Ca^(2+) on the SA-induced resistance Botrytis cinerea in tomato through proteomics analysis.A proteomic approach was used to uncover the inducible proteins of tomato in the susceptible tomato cultivars ‘L402' against Botrytis cinerea after salicylic acid(SA) and a combination treatment of CaCl_2 and SA.The results showed that the use of combination treatment of CaCl_2 and SA significantly enhanced tomato resistance against Botrytis cinerea.In total,46 differentially expressed protein spots from 2-DE gel maps were detected,of which 41 were identified by mass spectrometry.All the identified proteins were categorized into eight groups according to their putative functions:defense response(14.00%),antioxidative protein(9.75%),photosynthesis(24.39%),molecular chaperone(4.88%),energy(17.01%),metabolism(21.95%),protein synthesis(4.88%) and signal transduction(0.2%).Of the proteins in the eight function groups,the effect of stress/defense and reactive oxygen species on Ca^(2+) -regulated SA-induced resistance may be the most important one in induced resistance by RT-PCR.The expression level of pathogenesis-related proteins(PRs) and chitinase was upregulated by a combination treatment of CaCl_2 and SA.The characterization of these proteins greatly helped to reveal the induced proteins involved in the regulation of Ca^(2+) on SA-induced resistance to Botrytis cinerea.In the combination treatment of CaCl_2 and SA,the defense response and antioxidative protein were clearly upregulated much more than SA alone or the control treatment by the method of proteomics and RT-PCR.The present findings suggest that susceptible tomato cultivars treated by the combination treatment of CaCl_2 and SA might possess a more sensitive SA signaling system or effective pathway than SA treatment alone.In addition,results indicated that SA could coordinate other cellular activities linked with photosynthesis and metabolism to facilitate defense response and recovery,indicating that the self-defense capability of tomato was improved by the combination treatment of CaCl_2 and SA.

Gh_D11G050000参与棉花黄萎病抗性的功能分析

【目的】克隆Gh_D11G050000基因,解析其在棉花黄萎病抗性反应中的功能和作用机制,为开展棉花抗病分子育种提供理论依据。【方法】利用生物信息学方法分析Gh_D11G050000基因的序列特征和系统进化关系。通过实时荧光定量聚合酶链式反应(quantitative real-time polymerase chain reaction, qRT-PCR)分析该基因的表达模式以及大丽轮枝菌(Verticillium dahliae)侵染后的表达量变化。利用病毒诱导的基因沉默(virus-induced gene silencing, VIGS)技术初步验证该基因的功能。通过转录组测序分析和相关基因的表达量测定初步解析其抗病机制。【结果】Gh_D11G050000与Gh_A11G049600和Gr_11G034620蛋白的亲缘关系最近。qRT-PCR分析发现,Gh_D11G050000在棉花根部的表达量最高;该基因的表达量在大丽轮枝菌侵染后显著增加。Gh_D11G050000沉默植株对大丽轮枝菌的抗性减弱,具体表现为茎秆维管束褐变加重,有病菌繁殖的茎段数量明显增加,病株率和病情指数显著升高。转录组及qRT-PCR分析表明,Gh_D11G050000沉默棉株中茉莉酸、乙烯信号通路和木质素合成途径中相关基因的转录水平降低。【结论】Gh_D11G050000通过影响木质素合成基因、茉莉酸和乙烯信号通路相关基因的表达正调控棉花对黄萎病的抗性。

脐橙采后草酸浸泡处理抑制指状青霉侵染的效应

为研究外源草酸诱导脐橙果实抗采后绿霉病的效应和抗氧化能力之间的关系,并筛选出外源草酸处理适宜浓度,以八九成成熟的“龙回红”脐橙果实为试验材料,分别使用0(清水对照)、12.5、25.0、50.0 mmol·L^(-1)草酸浸泡10 min后,在25℃环境中诱导抗性48 h,再刺伤接种指状青霉(Penicillium digitatum)孢子悬浮液,通过分析病斑直径筛选出外源草酸处理的最适浓度,并测定果实经最适浓度草酸处理和接种孢子悬浮液后黄皮层总酚和类黄酮含量、抗氧化酶活性和丙二醛(Malonaldehyde,MDA)含量及其动态变化。结果表明,12.5、25.0、50.0 mmol·L^(-1)草酸处理诱导脐橙抗绿霉病的效果分别为16.26%、25.22%和17.36%,25.0 mmol·L^(-1)的诱导效果显著高于其他浓度。25.0 mmol·L^(-1)草酸处理可以提高果实黄皮层抗坏血酸过氧化物酶、过氧化物酶和多酚氧化酶活性,增加总酚和类黄酮积累,提高自由基清除能力,抑制MDA积累,从而减轻脐橙绿霉病的发生。25.0 mmol·L^(-1)草酸处理提高脐橙对采后绿霉病的抗性,可能与其诱导提高了脐橙抗氧化能力密切相关。

β-氨基丁酸诱导枸杞抗根腐病的响应机制

【目的】探究β-氨基丁酸诱导枸杞抗根腐病的生理机制,为枸杞根腐病的高效防治提供参考。【方法】分别以β-氨基丁酸诱导的枸杞根系和清水灌根的枸杞根系(对照)为材料,针刺接种尖孢镰刀菌,分别在接种后0和128 h测定枸杞根腐病病斑面积,计算病情指数并提取枸杞根系代谢物。通过代谢组学方法分析诱导组和枸杞-镰刀菌互作组枸杞根系中的差异代谢物,结合多元统计分析方法解析代谢物的变化情况。【结果】经β-氨基丁酸诱导的枸杞根系在接种尖孢镰刀菌128 h时枸杞根腐病的病斑面积和病情指数显著低于对照组。代谢组学共筛选出79种显著上调差异代谢物和94种显著下调差异代谢物。多元统计分析结果显示,诱导组和互作组组内的重复样本相关性极强、重复性好,可以用于后续差异代谢物分析。KEGG富集分析发现,诱导组中氨酰基-tRNA生物合成通路存在显著差异代谢物富集,互作组中氨酰基-tRNA生物合成和氰基氨基酸代谢通路存在显著差异代谢物富集。代谢物热图分析结果显示,诱导组中甘氨酸、组氨酸、脯氨酸、天冬氨酸、谷氨酸、天门冬酰胺和色氨酸含量分别上调了211.5%,206.1%,182.5%,176.5%,118.0%,106.7%和75.2%;互作组中β-氰基丙氨酸、天门冬氨酸、天门冬酰胺、异亮氨酸、酪氨酸、缬氨酸和苯丙氨酸含量分别上调了440.5%,403.6%,304.1%,219.2%,185.9%,185.2%和169.5%。【结论】氨酰基-tRNA生物合成和氰基氨基酸代谢通路可能是β-氨基丁酸诱导枸杞抗根腐病的关键代谢途径。

Epsilon-poly-L-lysine increases disease resistance of citrus against postharvest green mold by activating amino acid metabolism and phenolic comnpounds biosynthesis

As a famous fruit worldwide,citrus is susceptible to green mold caused by Penicillium digitatum,which causes large economic losses every year.e-Poly-L-lysine(e-PL)is a novel preservative with strong inhibitory effects on fungi,and has the capacity to induce disease resistance in fruit,but the mechanism has been reported rarely,especially in citrus.In the present study,8ooμg/mL e-PL and P digitatum spores were inoculated in two different wounds on the citrus pericarp at an interval of 24 h.The results revealed that e-PL inhibited that the development of green mold without direct contact with P digitatum,indicating that the disease resistance of citrus was activated.Transcriptome analysis revealed that e-PL activated amino acid metabolism and phenylpropanoid biosynthesis.Besides,the accumulation of glutamic acid,proline,arginine,serine,lysine,phenylalanine,and tyrosine were changed during storage.In phenylpropanoid biosynthesis,-PL increased phenylalanine ammonia-lyase(PAL),cinnamate 4-hydroxylase(C4H),and 4-coumarate:coenzyme A ligase(4CL)activities and total phenolic and flavonoid contents.Importantly.among these phenolic compounds,e-PL promoted the accumulation of individual phenolic compounds including ferulic acid,chlorogenic acid,p-coumaric acid,caffeic acid,gallic acid,catechins,epicatechin,and narirutin.In conclusion,e-PL enhanced the resistance of citrus through amino acid metabolism and accumulation of phenolic compounds.These results improved the knowledge of the mechanism of-PL-induced disease resistance and provided a fresh theoretical basis for the use of e-PL in postharvest citrus preservation.

Analysis of Salicylic Acid Induced Proteins in Rice

An analysis using SDS\|PAGE of acidic and basic protein fractions extracted from rice seedling treated with salicylic acid (SA) yielded several new proteins, some of which are similar in relative molecular mass to PR\|1a,c, PR\|2, 2e and PR\|3d, 3e of tobacco. Direct assays for peroxidases and β\|1,3\|glucanases demonstrated that the activities of the two enzymes in the rice seedlings increased rapidly with time after SA treatment, reaching a maximum 6 days after treatment.Disease resistance tests showed that SA treated rice seedlings stunted the development of blight lesions and displayed higher resistance to rice blight pathogen ( Xanthomonas oryzea pv. oryzea ). The data suggest that the treatment with SA, even for plants with high endogenous SA levels such as rice, may induce the appearance of new proteins and the formation of disease resistance. The results contribute to the analysis of the SA role in rice systemic acquired resistance.

叶酸联合维生素B_(12)二甲双胍对2型糖尿病患者治疗效果

目的对叶酸、维生素B_(12)(VB_(12))、二甲双胍联用对2型糖尿病(T2DM)患者的治疗作用。方法选取2021年2月至2023年3月浙江省医疗健康集团长兴医院收治的112例T2DM患者,采用随机数字表法分为对照组(VB_(12)^(+)二甲双胍,56例)和研究组(叶酸^(+)VB_(12)^(+)二甲双胍,56例)。对比血糖、糖化血红蛋白(HbA1c)、空腹胰岛素(FINS)水平、胰岛素抵抗指数(HOMA-IR)和同型半胱氨酸(Hcy)水平、临床疗效、CD4^(+)、CD8^(+)、CD4^(+)/CD8^(+)水平、Th1、Th17、Th1/Th17水平,不良反应及并发症。结果治疗后,研究组空腹血糖(FPG)、餐后2 h血糖(2 h PG)、HOMA-IR、HbA1c、FINS和Hcy均低于治疗前与对照组(P<0.05);研究组总有效率更高(P<0.05);治疗后研究组CD4^(+)、CD4^(+)/CD8^(+)均高于治疗前和对照组(P<0.05),CD8^(+)低于治疗前和对照组(P<0.05);治疗后,研究组Th1、Th17水平低于治疗前和对照组(P<0.05),Th1/Th17高于治疗前和对照组(P<0.05);2组患者不良反应发生率比较差异无统计学意义(P>0.05);研究组并发症发生率低于对照组(P<0.05)。结论叶酸与VB_(12)、二甲双胍联用治疗T2DM有助于控糖,还可提高免疫,调节Th1/Th17平衡,且安全可靠,有助于减少并发症。

水杨酸等4种诱导剂诱导辣椒抗疫病作用的研究

对水杨酸(SA)、CaCl2、KH2PO4和VA菌根4种诱导剂诱导辣椒抗疫病的作用试验结果表明,4种诱导剂中,只有SA能显著提高辣椒的抗疫病性,其它3种诱导剂对辣椒的抗性无明显影响。SA处理的最佳浓度范围为0.15～0.3g·L-1,SA处理后1～5d接种辣椒疫霉菌,辣椒植株开始表达出较高的诱导抗性,这种抗病作用可持续20d以上。低浓度的SA(<0.3g·L-1)对疫霉菌没有直接的抑菌作用,说明辣椒苗产生的抗性主要是诱导抗性。

水杨酸对黄瓜植株抗病酶系和白粉病抗性的诱导作用

水杨酸对黄瓜植株抗病酶系和白粉病抗性的诱导作用进行了研究,结果表明,5mmoL/L水杨酸喷雾处理黄瓜幼苗后,植株体内PAL,POD和PPO活性均有所提高。其中PAL活性升高迅速,在处理后24h即达到最大值;PPO活性在处理后24h开始提高,48h时达到最大值;POD活性在处理后8h即开始升高,48h时达到最大值。并且经水杨酸处理的植株抗病性明显增强,处理后7d对黄瓜白粉病的相对防治效果为51 23%。

水杨酸诱导马铃薯疮痂病抗性的生理机制研究

以感病品种夏波蒂为材料,研究外源水杨酸(SA)在温室马铃薯种薯生产中,对种薯疮痂病的感病指数和植株生长的影响。通过分析植株叶片过氧化物酶、PAL活性、叶绿素含量、可溶性蛋白含量等多种生理指标的变化,探索诱导抗性的生理基础。结果表明,外源SA能显著降低种薯感病率;同时矮化植株,抑制地上部分生长,增强叶片叶绿素和类胡萝卜素合成。通过诱导抗氧化酶系活力的提高,SA能有效降低叶片中超氧自由基和MDA的含量,增强植株对疮痂病的系统抗性。