Benzothiadiazole enhances resveratrol and anthocyanin biosynthesis in grapevine, meanwhile improving resistance to Botrytis cinerea

Pre-harvest multiple treatments of grapevine (cv. Merlot) with the plant activator benzothiadiazole (BTH, 0.3 mM) enhanced trans-resveratrol content in berries by about 40%. An even more striking effect was observed on anthocyanin synthesis, particularly on malvidine 3-glucoside, malvidine 3-(6-O-acetyl)glucoside and malvidine 3-(6-O-p-coumaroyl)glucoside, whose amounts were more than doubled. These data were obtained with a novel and time-saving HPLC method, set up for the simultaneous detection of stilbenes and anthocyanins, using an RF-10Axl fluorimetric detector instrument, with excitation at 330 nm and emission at 374 nm, and a SPD-Avp UV detector with absorption at 520 nm. Furthermore, BTH treatments induced systemic acquired resistance in grapevine, as assessed by inoculating clusters from treated and untreated plants with Botrytis cinerea. Disease severity, estimated according to the percentage of infected berries per cluster, was significantly reduced in grapes from BTH-treated plants. These results indicate that BTH treatments, besides improving the content of two important classes of nutraceuticals, with their well-known antioxidant, antitumoral, and phytoestrogenic activities, could be exploited in vineyard to protect grape against gray mould infection, thereby limiting an excessive use of fungicides     

From field to health: a simple way to increase the nutraceutical content of grape as shown by NO-dependent vascular relaxation

Polyphenolic grapevine components involved in plant resistance against pathogens possess various pharmacological properties that include nitric oxide (NO)-dependent vasodilation and anti-inflammatory and free radical scavenging activities, which may explain the protective effect of moderate red wine consumption against cardiovascular disease. The aim of this work was (a) to verify the possibility that preharvest treatments of grapevine with a plant activator, benzo-(1,2,3)-thiadiazole-7-carbothioic acid S-methyl ester (BTH), could lead to an enriched nutraceutical potential of wine and (b) to characterize the profile of metabolites responsible for pharmacological activity. Plant spraying at the end of veraison, with a water suspension of BTH (0.3 mM), led to increased whole anthocyanin content as confirmed by HPLC comparative analysis. Extracts from berry skins of BTH-treated grapevines caused NO-dependent vasorelaxation, with a concentration-response curve that was significantly shifted to the left of the control non-BTH-treated curve. Moreover, 1:1000 dilutions of berry extracts from BTH-treated plants significantly increased basal production of guanosine 3',5'-cyclic monophosphate (cGMP) in human vascular endothelial cells when compared to the corresponding extracts of untreated plants. These results show that BTH treatment increases anthocyanin content of grape extracts, as well as their ability to induce NO-mediated vasoprotection. No increase of anthocyanin content was observed in the wine extracts from BTH-treated vines. It is concluded that BTH treatment could be exploited to increase the nutraceutical potential of grapes.     

Benzothiadiazole induces the accumulation of phenolics and improves resistance to powdery mildew in strawberries

Benzothiadiazole (BTH) enhanced the accumulation of soluble and cell-wall-bound phenolics in strawberry leaves and also improved the resistance to powdery mildew infection under greenhouse conditions. The most pronounced change was seen in the levels of ellagitannins, which increased up to 2- to 6-fold 4 days after the BTH application, but persisted only in the inoculated plants. The induction of phenolic metabolism by BTH was also reflected in the fruits, several compounds being increased in inoculated, BTH-treated plants. Basal salicylic acid (SA) content was high in strawberry leaves, but increased in a similar fashion to other phenolics after the treatments. Several phenolic compounds were identified in strawberries for the first time. For example, ellagic acid deoxyhexose, three agrimoniin-like ellagitannins, sanguiin H-10- and lambertianin C-like ellagitannins in the leaves, ellagic acid, p-coumaric acid, gallic acid, and kaempferol hexose in the cell-wall-bound fraction of the leaves, and kaempferol malonylglucoside in the fruits. The findings show that BTH can enhance the accumulation of phenolics in strawberry plants which may then be involved in the BTH-induced resistance to powdery mildew.     

Effect of chemical systemic acquired resistance elicitors on avenanthramide biosynthesis in oat (Avena sativa)

Oats produce a group of phenolic antioxidants termed avenanthramides. These metabolites are, among food crops, unique to oats and have shown, in experimental systems, certain desirable nutritional characteristics such as inhibiting atherosclerotic plaque formation and reducing inflammation. Avenanthramides occur in both the leaves and grain of oat. In the leaves they are expressed as phytoalexins in response to crown rust (Puccina coronata) infection. The experiments reported here demonstrate that avenanthramide levels in vegetative tissue can be enhanced by treatment with benzothiadiazole (BTH), an agrochemical formulated to elicit systemic acquired resistance (SAR). The response to BTH was dramatically stronger than those produced with salicylic acid treatment. The roots of BTH treated plants also showed a smaller but distinct increase in avenanthramides. The dynamics of the root avenanthramide increase was substantially slower than that observed in the leaves, suggesting that avenanthramides might be transported from the leaves.     

Soil properties,but not plant nutrients (N,P, K) interact with chemically induced resistance against powdery mildew in barley

Chemically induced resistance is a promising method of plant protection against diseases, which can be triggered by systemically acting chemical inducers such as BTH (benzo(1, 2, 3)thiadiazole‐carbothioic‐acid‐S‐methylester). BTH is commercially distributed as a 50 % formulation, called Bion®. The uncertain success of Bion® application in controlling infection by powdery mildew is a major obstacle in using induced resistance for plant protection in agriculture. This study aimed to investigate the effect of soil properties, selected macronutrients (N, P, and K), and addition of organic matter on induced resistance and to identify possible factors responsible for the high variability of BTH effect under field conditions. A pot experiment under open‐air conditions was set up using the pathosystem Hordeum vulgare cv. Ingrid / Blumeria graminis f. sp. hordei race A6. The different soils strongly affected the resistance of barley plants against powdery mildew after BTH treatment. The infection of barley by powdery mildew was lower than on all other soils when grown on an acid forest soil which was limed up to pH 4.9, even after BTH treatment. A reproducible induction of pathogen resistance by BTH was shown only on a mineral soil (Kleinlinden) with a negligible C content. Application of N, P, and K did not consistently affect the induction of resistance by BTH. The addition of green manure and compost led to an enhanced variability of resistance induction on the soil “Kleinlinden”. Possible effects of soil microflora on resistance induction are discussed.     

苯并噻二唑(BTH)诱导小麦对条锈病抗性的研究

小麦条锈病是小麦生产中的重要病害之一,为了明确苯并噻二唑(Benzothiadiazole,BTH)对小麦条锈病的诱导抗性作用,分别以BTH处理后的苗期和成株期小麦为试验材料,诱发接种小麦条锈菌后调查小麦的发病情况及防治效果。温室苗期试验结果表明,与对照相比,不同浓度BTH处理后,小麦抗锈性明显提高,病情指数降低29.69~49.77,防治效果可高达90%左右,不同浓度处理之间有一定差异,但与对照相比差异极显著;BTH诱导的最佳浓度为0.3 mmol·L-1,BTH喷雾处理后6~7 d小麦诱导抗锈性表达最强,诱导抗性的持久期在15 d以上。田间成株期试验结果表明,不同浓度处理诱导的小麦抗锈性无明显差异,浓度为0.3 mmol·L-1的BTH诱导处理小区小麦的产量最高,千粒重最重,为42.21 g,增产最高达19.3%。小麦在分蘖期、拔节前期和分蘖期+拔节前期喷施BTH,都能诱导小麦抗条锈性增强,病情指数显著降低,防治效果分别为43.07%、47.43%和50.01%,增产13.4%~16.9%。综上所述,BTH可以诱导小麦产生抗锈性,对小麦条锈病防治起到积极作用。     

Improving grape phenolic content and wine chromatic characteristics through the use of two different elicitors: methyl jasmonate versus benzothiadiazole

Benzothiadiazole (BTH) and methyl jasmonate (MeJ) have been described as exogenous elicitors of some plant defense compounds, polyphenols among them. The objective of this study was to determine whether the application of BTH or MeJ to grape clusters at the beginning of the ripening process had any effect on the accumulation of the main flavonoid compounds in grapes (anthocyanins, flavonols, and flavanols) and the technological significance of these treatments in the resulting wines. The results obtained after a 2 year experiment indicated that both treatments increased the anthocyanin, flavonol, and proanthocyanidin content of grapes. The wines obtained from the treated grapes showed higher color intensity and total phenolic content than the wines made from control grapes. The exogenous application of these elicitors, as a complement to fungicide treatments, could be an interesting strategy for vine protection, increasing, at the same time, the phenolic content of the grapes and the resulting wines.     

模拟降雨下铜基保护剂对茄子生长防病效果的影响

降雨是影响铜制剂喷施效果的重要因素,该文探究模拟降雨条件下喷施铜基保护剂在茄子(Solanum melongena L.)叶片上的淋失情况及其对茄子的生长作用.以传统波尔多液为对照,通过茄子盆栽试验,研究模拟17.1、33.7和58.7 mm/h强度降雨后铜基保护剂在叶片上的淋失率及其对茄子防病效果、产量、生物量和土壤全铜、有效铜含量的影响.结果表明,铜基保护剂的表面张力较清水和传统波尔多液分别降低了37.0%和33.4%(P<0.05),与茄子叶片的接触角度较清水和传统波尔多液显著降低了28.1%和31.2%(P<0.05).在茄子幼苗期、始花期和结果期,17.1 mm/h降雨强度下喷施铜基保护剂的茄子叶片上的淋失率较传统波尔多液处理分别减少了33.2%、10.2%和32.0%(P<0.05),33.7 mm/h降雨强度下分别减少了19.3%、15.2%和19.2%(P<0.05),58.7 mm/h降雨强度下分别减少了15.5%、11.5%和20.9%(P<0.05).在结果期,33.7和58.7 mm/h降雨强度下铜基保护剂处理的灰霉病防治效果较传统波尔多液分别提高了70.8%和181.0%(P<0.05),地上部鲜质量提高了17.2%和17.3%(P<0.05),叶片SPAD值提高了5.1%和4.4%(P<0.05).在结果期无降雨条件下喷施铜基保护剂处理较传统波尔多液的土壤有效铜含量减少了18.8%(P<0.05),在17.1、33.7和58.7 mm/h降雨强度下喷施铜基保护剂处理较喷施传统波尔多液处理的土壤有效铜含量分别减少了23.9%、41.8%和45.3%(P<0.05),土壤全铜含量减少了4.3%、9.1%和18.0%(P<0.05).因此,在3种降雨强度下茄子叶片上喷施铜基保护剂较传统波尔多液显著降低了保护剂的淋失率,提高了灰霉病的防治效果,增加了生物量,减少了土壤中铜的累积量.     

Benzothiadiazole-induced resistance modulates ozone tolerance

The effects of ozone on bean plants pretreated with the SAR activator benzothiadiazole (BTH) have been investigated after fumigations with an acute dose of the pollutant (200 nL x L(-1) for 4 h), carried out at different times from BTH application. BTH pretreatment induced opposite effects on bean susceptibility to O(3), depending on the time elapsed before fumigation. When this time was only 1-2 days, bean plants were more susceptible to O(3) than untreated controls, showing rapid and extensive cell death in both palisade and spongy mesophyll. These damages appeared to be closely correlated with the amount and localization of H(2)O(2) in the leaf tissues. In BTH-pretreated, but not fumigated, plants, H(2)O(2) accumulation occurred in the cell walls and no dead cells were detected, whereas O(3) fumigation of untreated plants produced H(2)O(2) accumulation also inside some palisade mesophyll cells, causing their death. When BTH pretreatments were carried out 5-7 days before fumigation, plants appeared to be more tolerant to O(3) compared to untreated controls. Under these conditions, no visible symptoms of phytotoxicity were observed for at least 2 weeks after fumigation and no H(2)O(2) accumulation was detected. Biochemical assays showed a significant increase in the ascorbate (AA) level, taking place from the fifth to the seventh day after BTH treatment and unaffected by O(3) when given at these times. Ascorbate peroxidase (APX) activity appeared to decrease during the first 2 days after BTH treatment, and the decrease was somewhat enhanced by fumigation. On the contrary, guaiacol peroxidase (GuPX) activity was found to steadily increase up to the fifth day after BTH treatment but showed a bimodal trend upon fumigation. These results suggest that, during the first 1-2 days after BTH application, the H(2)O(2) level is enhanced by O(3) over a critical threshold for cell viability. However, in the absence of the pollutant, H(2)O(2) decreases in the following days under the effect of AA accumulation and increased GuPX activity. As GuPX is known to promote cell wall lignification and protein cross-linking, these effects would protect plasmalemma from O(3) irreversible damage, provided the priming by BTH has been fully developed.     

臭氧结合拮抗酵母对草莓采后灰霉病的控制

为了寻找一种能够代替化学杀菌剂控制草莓采后病害的方法,试验研究了臭氧与罗伦隐球酵母（Cryptococcus laurentii (Ku?erath) Skinner）结合使用对草莓采后灰霉病的控制效果的影响。研究表明,臭氧处理能显著降低草莓采后灰霉病发病率、抑制草莓水果伤口处致病菌数目和抑制霉菌孢子的萌发。经过2 d的贮藏,臭氧处理与罗伦隐球酵母结合使用草莓灰霉病的发病率为29.63%,显著低于对照处理（70.37%）,同时也低于臭氧处理及罗伦隐球酵母单独处理的发病率（分别为48.15%和44.44%）。在20℃和4℃下培养,罗伦隐球酵母在水果伤口处能迅速地增长,并持续保持较高水平。臭氧处理与罗伦隐球酵母结合处理能诱导草莓果实的多酚氧化酶（PPO）、过氧化物酶（POD）、苯丙氨酸解氨酶（PAL）、过氧化氢酶（CAT）和b-1,3-葡聚糖酶（GLU）活性的提高,同时可以抑制脂氧合酶（LOX）活性的增加。     

Effect of Foliar Applied Plant Elicitors on Microbial and Nematode Populations in the Root Zone of Potato

Abstract

Systemic acquired resistance (SAR) is a process whereby a plant that successfully resists a pathogen becomes highly resistant to subsequent infection not only by the original pathogen but also by a wide variety of pathogens. Most SAR research has focused on resistance in leaves, so much less is known about the effectiveness of foliar applications of SAR compounds in the protection of plant roots and associated microorganisms in soil. This study was conducted to determine if foliar SAR‐inducing applications (BTH or harpin) negatively impact the potato root system beneficial rhizosphere microbial populations and activity or influence pathogenic nematode populations. Foliar applications of benzo (1,2,3) thiadiazole‐7‐carbothioic acid S‐methyl ester (BTH) and the microbial protein harpin applied in various combinations, timings, and rates showed no effects on microbial biomass, culturable bacteria, Pseudomonas populations, or N‐mineralization potentials over 2 years. No stimulatory or inhibitory effects on major bacterial populations were observed, indicating that SAR induction does not have a negative effect on general microbial populations or activities. BTH and harpin both reduced the numbers of lesion nematodes (Pratylenchus spp.) by potato harvest. BTH reduced root knot nematodes, Meloidogyne chitwoodi at the end of the season. In addition, BTH and high‐dose harpin (applied at the 4× rate) reduced the nematode infection index in comparison to the control. The SAR elicitors increased the population densities of nontarget free‐living nematodes in the soil compared to the control. Potato yields were not affected by plant elicitors but BTH and harpin both reduced the number of culled potatoes 26% compared to the control. Future studies are designed to determine if these plant elicitors have any direct effect on rhizosphere diversity or if plants with active defense pathways alter carbon flow and root exudates into the soil.     

定量评估京津冀气候变化和人类活动对植被NPP变化的 相对作用

气候变化和人类活动是影响植被生长的两个重要因素,定量评估两因素对京津冀地区植被净初级生产力（NPP）的相对作用,对了解该区域植被变化的驱动机制,改善生态环境具有参考价值。基于2001−2020年CASA模型的NPP数据和气象数据,采用“去趋势回归残差法”定量区分气候变化和人类活动对京津冀地区植被NPP的影响。结果表明：(1)京津冀地区47.8%的植被呈现显著改善的状态,4.5%呈现显著退化的状态。张家口中部地区植被NPP增加趋势最大,经济发达的城市群（除北京外）减少趋势显著;（2）京津冀大部分地区植被得到显著改善的主要原因为气候变化和人类活动的共同作用,其中气候变化对NPP影响为1.5gC·m−2·a−1,人类活动为2.4gC·m−2·a−1;（3）气候变化和人类活动对植被显著改善的贡献率平均为25.8%和74.2%。气候变化贡献率大于80%的区域面积约占1.3%,主要集中在张家口西北部、沧州东部等地;人类活动贡献率超过80%的区域面积占比22.1%,主要集中在张家口中部和西南部、承德大部、沧州南部、衡水大部等地。而人类活动对植被显著退化区的作用高达94.9%。研究结果表明人类活动在植被生长能力恢复和退化中的作用大于气候变化,因此,京津冀植被恢复的生态建设中应重点关注人类活动的影响。     

罗伦隐球酵母对草梅采后灰霉病害的生物防治

测定了罗伦隐球酵母对草莓采后由灰葡萄孢霉引起的灰霉腐烂的抑制效果。在马铃薯葡萄糖琼脂固体培养基（PDA）体外抑菌实验中，把生长有罗伦隐球酵母的营养酵母葡萄糖固体培养基(NYDA)切块放置在涂布有灰霉孢子的马铃薯葡萄糖琼脂固体培养基上一起培养，罗伦隐球酵母并不能抑制霉菌的生长；而在马铃薯葡萄糖液体培养基(PDB)体外抑菌实验中，罗伦隐球酵母活细胞有效地抑制了灰霉孢子的萌发。酵母细胞菌悬液对灰霉的抑菌效果好于酵母培养液，而酵母热杀死液和滤液没有抑菌作用。酵母菌悬液的细胞浓度对其抑菌作用有显著的影响：无论草莓在20℃条件下贮藏3 d或是在2℃条件下贮藏20 d，应用在草莓上的酵母细胞浓度越高，则草莓的霉变率越低。罗伦隐球酵母菌悬液对草莓整果储藏自然条件下霉变的抑制试验也有类似的结果。因此，罗伦隐球酵母可以代替化学杀菌剂作为草莓采后的霉菌抑制剂。     

The Influence of Silicon on the Components of Resistance to Gray Leaf Spot in St. Augustinegrass

ABSTRACT

Soil fertilization with silicon (Si) has been shown to reduce the severity of gray leaf spot, caused by Magnaporthe grisea, in St. Augustinegrass. However, to understand how Si reduces gray leaf spot, it is necessary to study the effects of Si on the components of host resistance. In a greenhouse, six rates (0, 0.5, 1, 2, 5, and 10 t ha^?1) of calcium silicate were evaluated for their ability to affect the components of resistance to gray leaf spot in the susceptible (‘Floratam’) and resistant (‘FX-10’) St. Augustinegrass cultivars. Components of resistance assessed were incubation period, latent period, lesion number, lesion area, daily rate of lesion expansion, and number of conidia per lesion. Percent leaf area diseased, a result of the components of resistance, was also evaluated. In this study, the only component of resistance affected by Si was lesion number. Silicon application significantly reduced the number of lesions 26 to 61% when compared to the untreated control in the susceptible cultivar ‘Floratam’. In the resistant cultivar ‘FX-10’, as the rate of calcium silicate increased the number of lesions decreased significantly from 43 to 57%. The percent leaf area diseased in ‘Floratam’ was significantly reduced (18–57%) by increasing rates of silicon when compared to the control. Silicon was the only element to increase significantly in the plant tissue from the amendment of soil with calcium silicate. Integrated disease management strategies for reducing gray leaf spot in both sod production and home lawn settings can be augmented by using Si fertilization to increase plant resistance to gray leaf spot, especially in soils deemed to be low in plant available Si.     

长期不同施肥模式对大麦-双季稻田根际土壤有机氮组分的影响

根际土壤有机氮组分在土壤养分和作物氮素营养中具有重要作用。本研究依托长期（37年）定位施肥试验田,设置4个施肥处理：不施肥对照（CK）、单独施用化肥（CF）、秸秆还田+化肥（RF）和30%有机肥+70%化肥（OM）,于晚稻成熟期测定大麦-双季稻田根际土壤基础理化性质、微生物量氮和有机氮组分（氨基酸态氮、氨基糖态氮、酸解氨态氮、酸解未知态氮、非酸解性氮）含量。研究表明：相对CK处理,RF和OM处理显著增加了稻田根际土壤有机碳、全氮、铵态氮和硝态氮的含量。RF和OM处理土壤微生物量氮含量分别比CK处理增加了19.8%和30.7%。酸解性氮作为根际土壤全氮的主体部分,占全氮的59.6%~72.1%;各处理根际土壤酸解性氮含量大小顺序表现为OM>RF>CF>CK。各施肥处理中,酸解有机氮中的氨基糖态氮、氨基酸态氮和酸解未知态氮含量均以OM处理最大,分别比CK处理增加139.3%、47.9%和110.0%;酸解氨态氮以RF处理最大,比CK处理增加69.9%。土壤有机碳、全氮、铵态氮、硝态氮与土壤氨基酸态氮、氨基糖态氮、酸解未知态氮以及微生物量氮均呈极显著（p<0.01）正相关。因此,秸秆、有机肥配施化肥均能有效提高大麦-双季稻田根际土壤的供氮能力,是改善稻田土壤肥力的有效手段。     

京津冀水资源脆弱性评价

[目的]评价京津冀水资源脆弱性,为京津冀水资源管理提供理论依据与数据支撑。[方法]选取人口密集、经济发达、水资源问题极为突出的京津冀区域,采用水足迹的理论与方法,构建了集水资源压力—发展压力—污染压力—水资源管理压力(RDHM)于一体的水资源脆弱性评价指标体系,采用层次分析法确定不同指标的权重,对该区域2003—2013年水资源脆弱性进行了评价。[结果]京津冀地区面临着水资源禀赋差,开发利用强度大,污染严重,水资源管理力度区域差异大等问题。北京市在水资源管理方面水平相对较高,但水污染压力长期没有得到有效缓解;天津市虽然在水资源管理上获得了长足的进步,但水资源脆弱性有增无减,其水资源问题的解决亟需寻找新的途径;河北省水资源管理相对京津地区差距较大,水资源脆弱性逐年突显,成为京津冀地区水资源问题的短板。[结论]缓解区域水污染压力,正视河北省水资源管理的滞后性,统一配置水资源,缩小水资源脆弱性区域差异在京津冀一体化背景下势在必行。     

植物源杀菌包膜复合肥对番茄生长、氮肥利用率及病害的影响

利用植物源杀菌材料作为包衣剂研制出杀菌包膜复合肥, 在番茄小区试验中研究了其杀菌及对番茄生长的影响。结果表明: 各杀菌包膜复合肥处理(分别用ZYF1~ ZYF5 表示)均能有效延缓养分的释放, 与施普通复合肥处理(CK1)相比各杀菌包膜复合肥处理土壤硝态氮在番茄生长后期仍能保持较高含量。除ZYF4 处理外, 其余杀菌包膜复合肥处理番茄产量均明显高于CK1, 其中ZYF3 处理番茄产量最高, 达11.1 kg·m^-2, 较CK1 高16.8%。各杀菌包膜复合肥处理的氮肥利用率也均大于CK1(33.3%), 其中ZYF2、ZYF3 处理分别较CK1 处理高9.9 个和9.5 个百分点。各杀菌包膜复合肥对番茄的Vc 含量无显著影响, ZYF1 处理显著降低了番茄的硝酸盐含量, 而ZYF2、ZYF4、ZYF5 处理则促进了番茄对硝酸盐的累积。各杀菌包膜复合肥处理显著降低了番茄枯萎病、灰霉病的发病率, 其中ZYF1 处理对这两种病菌均有较高的抑制作用, 使发病率较CK1 分别下降17.7 个和12.5 个百分点。     

Activity of antifungal proteins against mold in sorghum caryopses in the field

Sorghums were stressed with pathogenic fungi and sprinkling to determine relationships between changes in chitinase and sormatin in caryopses and grain mold resistance. Panicles of 10 cultivars differing in mold resistance and accumulation of antifungal proteins (AFPs) were inoculated at anthesis with Fusarium moniliforme and Curvularia lunata spores. Panicles were sampled at 30 and 50 days after anthesis, and caryopses were evaluated for chitinase and sormatin using western blots. Sprinkling panicles (to mimic rainfall) decreased sormatin and chitinase in most cultivars. Inoculation decreased AFPs in susceptible cultivars, but resistant cultivars maintained or increased AFPs in caryopses. Grain mold resistance corresponded to induction of AFP synthesis in response to sprinkling, fungal stress, and/or adverse field conditions. Sormatin and chitinase appear to be an active part of the defense mechanism of the caryopsis against grain mold.     

Novel benzo-1,2,3-thiadiazole-7-carboxylate derivatives as plant activators and the development of their agricultural applications

Plant activators are a novel kind of agrochemicals that could induce resistance in many plants against a broad spectrum of diseases. To date, only few plant activators have been commercialized. In order to develop novel plant activators, a series of benzo-1,2,3-thiadiazole-7-carboxylate derivatives were synthesized, and the structures were characterized by (1)H NMR, IR, elemental analyses, and HRMS or MS. Their potential systemic acquired resistance as plant activators was evaluated as well. Most of them showed good activity, especially, fluoro-containing compounds 3d and 3e, which displayed excellent SAR-inducing activity against cucumber Erysiphe cichoracearum and Colletotrichum lagenarium in assay screening. Field test results illustrated that compounds 3d and 3e were more potent than the commercial plant activator, S-methyl benzo[1,2,3]thiadiazole-7-carbothioate (BTH) toward these pathogens. Further, the preparation of compound 3d is more facile than BTH with lower cost, which will be helpful for further applications in agricultural plant protection.     

水稻白叶枯病菌蛋白质激发子HarpinXoo诱导植物的防卫反应

摘要：含质粒pHRF4的表达菌株BLHR4在培养基中经IPTG诱导，16 h Harpin表达接近最高量。用不同浓度的HarpinXoo喷雾处理烟草(Nicotiana tabacum L.)、油菜(Brassica campestris L.)和番茄(Lycopersicon esculentum Mill.)，对烟草花叶病毒(TMV)、油菜菌核病(Sclerotinia sclerotiorum (lib.) de Bary)和番茄灰霉病(Botrytis cinerea Pers.)均表现较好的诱导抗病效果。以浓度为100μg/mL的HarpinXoo处理烟草后，分别测定叶片中与防卫反应相关的一些生理指标的变化，结果表明，处理叶片中苯丙氨酸解氨酶（PAL）、过氧化物酶（PO）和多酚氧化酶（PPO）活性都有不同程度的增强。三种酶活性高峰分别在处理后24、12和3 h出现，分别比清水对照增加110.1%、211.2%和273.0%；同时，两个病程相关蛋白（pathogenesis-related protein，PR）基因PR-1b和PR-1a在HarpinXoo处理24 h后被诱导显著表达，36 h时达到最高表达水平。这表明HarpinXoo与HarpinEa一样能够诱导烟草不同抗病信号通路的启动，从而使植株获得抗病性。