N-｛5-[1-(2,4-二氯苯氧)乙基]-1,3,4-噻二唑-2-基｝ -N''-芳酰基硫脲的合成及其生物活性

通过2-氨基-5- -1,3,4-噻二唑与芳酰基异硫氰酸酯反应,合成了12 个新的芳酰基硫脲,采用核磁共振氢谱、红外光谱和元素分析确证了它们的结构。初步的生物活性测定试验表明,部分化合物具有良好的植物生长调节活性,其中化合物 2c、2j 具有较好的生长素活性,其促进率分别为26.6%与26.9%,但不及对照β-吲哚乙酸。     

N-{5-[1-(2,4-二氯苯氧)乙基]-1,3,4-噻二唑-2-基}-N′-芳酰基硫脲的合成及其生物活性

通过2-氨基-5-[1-(2,4-二氯苯氧)乙基]-1,3,4-噻二唑与芳酰基异硫氰酸酯反应,合成了12个新的芳酰基硫脲,采用核磁共振氢谱、红外光谱和元素分析确证了它们的结构。初步的生物活性测定试验表明,部分化合物具有良好的植物生长调节活性,其中化合物2 c、2 j具有较好的生长素活性,其促进率分别为26.6%与26.9%,但不及对照β-吲哚乙酸。     

新型腙类衍生物的合成及其生物活性

利用3-(N-甲基-N-甲氧基氨基)-1-芳基-1-丙酮腙与酰氯反应,合成了14个新型N-酰基-3-(N-甲基-N-甲氧基氨基)-1-芳基-1-丙酮腙化合物,其化学结构经1H核磁共振和元素分析确证。初步的生物活性测试结果表明,部分化合物在50 mg/L时对淡色库蚊Culex pipiens pallens的致死率为95%~100%;化合物 c7 在1 000 mg/L时对粘虫Leucania separata Walke 的致死率达100%。     

健大素在温室樱桃番茄上的应用效果

为调查植物生长调节剂健大素2号应用于温室樱桃番茄的效果,对幼果期樱桃番茄果穗进行800倍液和1 500倍液浸药处理,到果实成熟期测定果实横、纵径,发现该药剂2种浓度均能够促进樱桃番茄果实膨大。其800倍液处理的效果最为明显,试验测得果实横、纵径最终膨大率分别达到123.16%和103.78%,比清水对照分别高出46.49和44.80百分点。1 500倍液处理比清水对照分别高出44.09和39.75百分点。     

N-(5-芳基-1,3,4-噁二唑-2-基)-N′-α-萘乙酰基硫脲的合成及杀菌活性

从α-萘乙酸出发,合成酰基异硫氰酸酯,然后与2-氨基-5-芳基-1,3,4-二唑反应合成了8个新的酰基硫脲类化合物 a～ h。所有化合物的结构均经元素分析、红外光谱、核磁共振氢谱和质谱确认。同时对6种病原菌进行了生物活性测试,结果发现,在50mg/L下,所有目标化合物对黄瓜灰霉病菌Botrytiscinereapers的抑制效果较好,除 a外,其他化合物抑制率都达到80%以上。     

2-噻唑酰氨基环己烷基磺酰胺的合成与杀菌活性

为进一步研究环烷基磺酰胺类化合物的杀菌活性与构效关系,在前期工作基础上,合成了11个未见文献报道的2-噻唑酰氨基环己烷基磺酰胺类化合物 ( 7a ~ 7k ),其结构均经1H NMR、13C NMR、质谱和元素分析确证。分别采用菌丝生长速率法、黄瓜活体叶片法、孢子萌发法和番茄活体盆栽法对目标化合物进行了生物活性测定。结果表明:目标化合物对番茄灰霉病菌Botrytis cinerea表现出较好的抑制活性,其中化合物 7a 和 7c 在10 mg/L下对番茄灰霉病菌孢子萌发的抑制率分别为90%和67%;在200 mg/L 施药剂量下,对活体黄瓜叶片、番茄叶片和番茄花上灰霉病的防治效果,化合物 7a 分别为75%、78%和30%,化合物 7c 分别为78%、62%和44%,均优于对照药剂腐霉利,有进一步研究的价值。     

N-(5-芳基-1,3,4-嗯二唑-2-基)-N''-α-萘乙酰基硫脲的合成及杀菌活性

从α-萘乙酸出发,合成酰基异硫氰酸酯,然后与2-氨基-5-芳基-1,3,4-嗯二唑反应合成了8个新的酰基硫脲类化合物 Ⅱa~Ⅱh 。所有化合物的结构均经元素分析、红外光谱、核磁共振氢谱和质谱确认。同时对6种病原菌进行了生物活性测试,结果发现,在50 mg/L下,所有目标化合物对黄瓜灰霉病菌Botrytis cinereapers的抑制效果较好,除 Ⅱa 外,其他化合物抑制率都达到80%以上。     

N-(5-芳基-1,3,4-(口恶)二唑-2-基)-N''-α-萘乙酰基硫脲的合成及杀菌活性

从α-萘乙酸出发,合成酰基异硫氰酸酯,然后与2-氨基-5-芳基-1,3,4-(口恶)二唑反应合成了8个新的酰基硫脲类化合物Ⅱa～Ⅱh.所有化合物的结构均经元素分析、红外光谱、核磁共振氢谱和质谱确认.同时对6种病原菌进行了生物活性测试,结果发现,在50 mg/L下,所有目标化合物对黄瓜灰霉病菌Botrytis cinereapers的抑制效果较好,除Ⅱa外,其他化合物抑制率都达到80%以上.     

N-(5-芳基-1,3,4-噁二唑-2-基)-N′-4-氟苯氧乙酰基硫脲的合成及抑菌活性

为了寻找更好的具有生物活性的化合物,从4-氟苯氧乙酸出发先合成酰基异硫氰酸酯,再与2-氨基-5-芳基-1,3,4-(噁)二唑反应合成了10个新的酰基硫脲类化合物,其结构经红外光谱、核磁共振氢谱、质谱和元素分析确认.采用平皿培养菌落生长速率法对6种病原菌进行了初步的生物活性测试,结果表明,在50 mg/L浓度下,大部分化合物对黄瓜灰霉病菌Botrytis cinereapers、小麦赤霉病菌Gibberella zeae的抑制率达60%以上,其中Ⅱa、Ⅱc两个化合物对小麦赤霉病菌的抑制率达90%以上.     

N-(5-芳基-1,3,4-噁二唑-2-基)-N′-4-氟苯氧乙酰基硫脲的合成及抑菌活性

为了寻找更好的具有生物活性的化合物,从4-氟苯氧乙酸出发先合成酰基异硫氰酸酯,再与2-氨基-5-芳基-1,3,4-噁二唑反应合成了10个新的酰基硫脲类化合物,其结构经红外光谱、核磁共振氢谱、质谱和元素分析确认。采用平皿培养菌落生长速率法对6种病原菌进行了初步的生物活性测试,结果表明,在50mg/L浓度下,大部分化合物对黄瓜灰霉病菌Botrytis cinereapers、小麦赤霉病菌G ibberella zeae的抑制率达60%以上,其中Ⅱa、Ⅱc两个化合物对小麦赤霉病菌的抑制率达90%以上。     

Molecular and genetic characterization of ethylene involvement in mycotoxin-induced plant cell death

AAL-toxin and the structurally related mycotoxin, fumonisin B₁(FB₁), cause interveinal cell death in susceptible lines of tomato with morphological characteristics of apoptosis. We observed previously that concomitant with cell death, an increase in 1-aminocyclopropane-1-carboxylic acid (ACC) and ethylene occurs, while the addition of inhibitors of ethylene biosynthesis or action significantly reduce the amount of dead tissue. Using a molecular approach, we have identified the primary ACC synthase gene family member involved, LE ACS2, and have observed an interesting aspect of its regulation. Fumonisin B₁caused the accumulation of LE ACS2 mRNA with a similar time course but to a lower level than did AAL-toxin. Nevertheless, ACC levels were similar for AAL- and FB₁-treated tissue. ACC oxidase mRNA was also induced by both mycotoxins, and again AAL-toxin induction was greater than that with FB₁. The induction of ACC synthase and ACC oxidase mRNA observed here represents the earliest changes in gene expression noted in this cell death system to date. The effects of theNever ripemutation of tomato, which affects ethylene perception, on toxin-induced cell death also were determined. TheNever ripemutant showed significantly less necrosis or chlorosis in response to the mycotoxins than did its wild type counterpart. These results indicate that alteration in ethylene perception can markedly reduce the amount of tissue damage during this susceptible response. These findings extend our understanding of ethylene-associated signal transduction during plant cell death and suggest strategies for manipulation of cell death to enhance plant disease resistance.     

Synthesis and bioactivity of novel sulfone derivatives containing 2,4-dichlorophenyl substituted 1,3,4-oxadiazole/thiadiazole moiety as chitinase inhibitors

The paper reported the synthesis and antifungal properties and mechanism of action of a series of 2-substituted methylthio-5-(2,4-dichlorophenyl)-1,3,4-oxadiazole/thiadiazole and their corresponding sulfones. The preliminary biological test showed these compounds exhibit moderate to good antifungal activity. Particularly, the compounds 7g and 7c inhibited mycelia growth by approximately 50% (EC₅₀) at 2.6–59.2 μg/mL and 17.2–54.4 μg/mL respectively against nine kinds of fungi. The extent of inhibition induced by 7c on Rhizoctonia solani and underlying mechanism of action were studied in vitro. Docking simulation was performed to position selected compounds into the active site of family 18 chitinases. Variation in d-GlcNAc content and chitinase activity indicated that 7c can act as chitinase inhibitor for controlling fungal pathogens in plants.     

Inhibitory effect of ACC deaminase‐producing bacteria on crown gall formation in tomato plants infected by Agrobacterium tumefaciens or A. vitis

This study showed that various rhizosphere bacteria producing the enzyme 1‐aminocyclopropane‐1‐carboxylate (ACC) deaminase (ACCD), which can degrade ACC, the immediate precursor of ethylene in plants, and thereby lower plant ethylene levels, can act as promising biocontrol agents of pathogenic strains of Agrobacterium tumefaciens and A. vitis. Soaking the roots of tomato (Solanum lycopersicum) seedlings in a suspension of the ACCD‐producing Pseudomonas putida UW4, Burkholderia phytofirmans PsJN or Azospirillum brasilense Cd1843 transformed by plasmid pRKTACC carrying the ACCD‐encoding gene acdS from UW4, significantly reduced the development of tumours on tomato plants injected 4–5 days later with pathogenic Agrobacterium strains via wounds on the plant stem. The fresh mass of tumours formed by plants pretreated with ACCD‐producing strains was typically four‐ to fivefold less than that of tumours formed on control plants inoculated only with a pathogenic Agrobacterium strain. Simultaneously, the level of ethylene evolution per amount of tumour mass on plants pretreated with ACCD‐producing bacteria decreased four to eight times compared with that from tumours formed on control plants or plants pretreated with bacteria deficient in ACCD production. Moreover, transgenic tomato plants expressing a bacterial ACCD were found to be highly resistant to crown gall formation relative to the parental, non‐transformed tomato plants. The results support the hypothesis that ethylene is a crucial factor in Agrobacterium tumour formation, and that ACCD‐produced rhizosphere bacteria may protect plants infected by pathogenic Agrobacteria from crown gall disease.     

烟粉虱传播的番茄褪绿病毒和番茄黄化曲叶病毒对不同番茄品种的复合侵染

为明确烟粉虱传播的番茄褪绿病毒(Tomato chlorosis virus,ToCV)与番茄黄化曲叶病毒(Tomato yellow leaf curl virus,TYLCV)对不同番茄品种的复合侵染情况,于2015年11月在山东省寿光市温室内采集13个番茄品种共390份疑似发病植株叶片,对不同番茄品种的TYLCV抗性和2种病毒的复合侵染以及温室内发病番茄植株上烟粉虱成虫的带毒率进行检测。结果表明,采集的13个番茄品种经分子标记检测鉴定均为TYLCV杂合抗性;不同番茄品种ToCV与TYLCV的复合侵染率存在明显差异,大果番茄粉宴和贝瑞上复合侵染率最高可达73.3%,而樱桃番茄八喜上未检测到这2种病毒的复合侵染。此外,在发病番茄植株上采集的烟粉虱成虫体内可检测到2种病毒,其中烟粉虱ToCV带毒率为90.7%,TYLCV带毒率为80.0%,同时检测到ToCV与TYLCV的概率为71.3%。表明ToCV和TYLCV的复合侵染在山东省番茄生产中普遍发生,烟粉虱可同时携带这2种病毒并广泛传播。     

Mechanism of resistance to quinclorac in smooth crabgrass (Digitaria ischaemum)

The mechanism of resistance to quinclorac was investigated in a smooth crabgrass biotype [Digitaria ischaemum (Schreb. ex Schweig) Schreb. ex Muhl] from Tulare County, California. Quinclorac (8.96 kg a.i. ha⁻¹) had no effect (P = 0.18) on the resistant (R) biotype, but reduced fresh weight of a susceptible (S) biotype by 93%. After treatment with 4.48 kg a.i. quinclorac ha⁻¹, the S biotype produced about three times more ethylene than the R biotype and accumulated cyanide in tissues. Similar amounts of endogenous cyanide resulting from treatment with KCN reproduced quinclorac phytotoxicity. Pre-treatment with the ACC synthase inhibitor AVG reduced quinclorac phytotoxicity by 37% and ethylene production by 89%. These data suggest a target site-based mechanism of resistance involving stimulation of ACC synthesis and accumulation of cyanide. Also, the R biotype had four times more β-cyanoalanine synthase activity than the S biotype, suggesting a higher ability to detoxify cyanide.     

枯草芽胞杆菌B1409对番茄和辣椒的防病促生作用

为探讨枯草芽胞杆菌Bacillus subtilis菌株B1409对番茄早疫病和辣椒疫霉病的防效和生防机制,采用平板对峙法和盆栽法测定了该菌株对番茄早疫病菌和辣椒疫霉病菌菌丝生长的抑制作用、对2种病害的盆栽防效以及对番茄和辣椒植株促生长效果和防御酶活性的影响。结果表明:菌株B1409能明显抑制番茄早疫病菌和辣椒疫霉病菌菌丝生长,且导致菌丝发生畸变。10~8CFU/mL菌株B1409菌液对番茄早疫病和辣椒疫霉病的预防效果分别为67.82%和61.22%,治疗效果分别为41.22%和56.43%。不同浓度B1409菌液均能促进番茄和辣椒植株生长,并能增强其体内超氧化物歧化酶、过氧化物酶和过氧化氢酶活性,且浓度越高促进效果越明显。番茄和辣椒植株的平均干重分别在10~2CFU/mL和10~4CFU/mL B1409菌液处理后显著高于对照,增长率分别为42.35%和4.87%。番茄和辣椒植株经10~2CFU/mL B1409菌液处理后,体内超氧化物歧化酶活性比对照显著增加,增长率分别为91.23%和19.58%。研究表明枯草芽胞杆菌B1409菌株可通过直接抑制菌丝生长及诱导植物体自身抗病性等方式来有效防治番茄早疫病和辣椒疫霉病。     

N-(2-三氟甲基-4-氯苯基)-2-吡唑酰氨基环己烷基磺酰胺类化合物的合成与杀菌活性

吡唑酰胺类杀菌剂是近年新农药开发的热点。本研究采用EDCI/HOBt酰胺化法合成了14个结构新颖的N-(2-三氟甲基-4-氯苯基)-2-吡唑酰氨基环己烷基磺酰胺类化合物 ( 3a ~ 3n ),其结构均经1H NMR、13C NMR、质谱和元素分析确认,并用X-射线衍射法确定了化合物 3g 的单晶结构和立体构型。菌丝生长速率法试验结果表明,化合物 3a 、 3e 和 3j 对番茄灰霉病菌Botrytis cinerea KZ-9的EC₅₀值分别为4.28、10.08和11.31 mg/L,抑菌活性不及对照药剂啶酰菌胺和腐霉利;但在孢子萌发试验中,目标化合物表现出与对照药剂相近的抑菌活性,在10 mg/L下有7个化合物对灰霉病菌孢子萌发的抑制率超过了85%;在番茄活体盆栽试验中,化合物 3e 在200 mg/L下对番茄叶片及其花上灰霉病菌的防治效果分别为77.5%和65.2%,高于对照药剂啶酰菌胺 (防效分别为59.8%和30.3%),有进一步研究的价值。     

含咪唑啉酮结构的吡唑类对羟基苯基丙酮酸双加氧酶抑制剂的除草活性及选择性研究

对羟基苯基丙酮酸双加氧酶（HPPD）是一种重要的除草剂作用靶标。为了发现具有高活性和高选择性的新型HPPD抑制型除草剂,对前期合成的23个含咪唑啉酮结构单元的吡唑类衍生物（2A~2W）进行了深入的生物活性评价和构效关系研究,比较了它们对拟南芥HPPD（AtHPPD）和人源HPPD（hHPPD）抑制活性的差异,从酶水平上总结了该类化合物的结构-活性关系和种属选择性规律,从活体植株水平研究了它们的除草活性。结果表明:部分化合物表现出良好的除草活性和作物安全性,其中化合物2E和2G在150 g/hm2剂量下对荠菜、繁缕、小藜和棒头草抑制活性达到80%以上,且其对作物的安全性也明显优于商品化除草剂硝磺草酮。此外,化合物2P在酶水平上的选择性倍数高达93倍,展示出良好的应用潜力。