Overexpression of Rice BSR2 Confers Disease Resistance and Induces Enlarged Flowers in Torenia fournieri Lind

Plant pathogens evade basal defense systems and attack different organs and tissues of plants. Genetic engineering of plants with genes that confer resistance against pathogens is very effective in pathogen control. Conventional breeding for disease resistance in ornamental crops is difficult and lagging relative to that in non-ornamental crops due to an inadequate number of disease-resistant genes. Therefore, genetic engineering of these plants with defense-conferring genes is a practical approach. We used rice BSR2 encoding CYP78A15 for developing transgenic Torenia fournieri Lind. lines. The overexpression of BSR2 conferred resistance against two devastating fungal pathogens, Rhizoctonia solani and Botrytis cinerea. In addition, BSR2 overexpression resulted in enlarged flowers with enlarged floral organs. Histological observation of the petal cells suggested that the enlargement in the floral organs could be due to the elongation and expansion of the cells. Therefore, the overexpression of BSR2 confers broad-spectrum disease resistance and induces the production of enlarged flowers simultaneously. Therefore, this could be an effective strategy for developing ornamental crops that are disease-resistant and economically more valuable.     

人参根腐病拮抗菌的筛选、鉴定及其抑菌活性

目的：从人参根际土壤中筛选出拮抗人参根腐病的菌株,初步研究其抑菌作用。方法：采用平板稀释法从人参根际土壤中分离获得菌株,以人参根腐病菌为靶标菌采用平板对峙法筛选出拮抗菌;通过形态学特征、生理生化特征及16S rDNA序列分析对筛选出的拮抗菌进行鉴定;检测拮抗菌无菌发酵液对根腐病菌菌丝生长、孢子萌发的影响,同时测定拮抗菌的抑菌谱。结果：分离获得一株对人参根腐病原菌拮抗作用较强的菌株HB-3,经鉴定菌株HB-3为解淀粉芽孢杆菌（Bacillus amyloliquefaciens）。菌株无菌发酵液对人参根腐病菌菌丝生长和孢子萌发均有显著抑制作用;菌株HB-3的抑菌谱较广,对根腐病菌、疫霉病菌、锈腐病菌、菌核病菌、灰霉病菌均有一定的抑菌活性。结论：筛选得到一株解淀粉芽孢杆菌HB-3,能显著抑制人参根腐病菌的生长,对人参根腐病有较强的生物防治效果。     

Cover Image,Volume 99, Issue 14

The cover image is based on the Short Communication Hydrolysis of chlorogenic acid in apple juice using a p-coumaryl esterase of Rhizoctonia solani by Mareike Siebert et al., https://doi.org/10.1002/jsfa.9940 .

     

Biopolymer films to control fusarium dry rot and their application to preserve potato tubers

Films were cast using sodium alginate (NaAlg), high molecular weight (HMW) chitosan, and low molecular weight (LMW) chitosan as film forming biopolymers. Fludioxonil (Fl) at 1% concentration was used as fungicide. Thermal stability, mechanical, and water sorption properties of the films were examined. The effects of films on the Fusarium solani colony radial growth were evaluated in vitro and in potato tubers. Results showed that chitosan films were more thermally stable and less hydrophilic than alginate films. Addition of fluodioxonil to the films significantly reduced the film strength and increased the elongation at break as well as the film stiffness. In vitro studies showed that when fludioxonil was added to the formulation, NaAlg and Chitosan‐LMW films had significantly higher antifungal activity (Fungistatic index = 56%) than Chitosan‐HMW films (Fungistatic index = 50%). In vivo studies showed that Chitosan‐LMW‐1%Fl films delay the mycelial growth of F. solani in tubers kept at 25 °C for 2 weeks. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44017.     

12.5%禾果利防治小麦纹枯病试验

12．5％禾果利对小麦纹枯病效果好,该农药与种子按300～400g/100kg拌种,病株率相对防效达到93．2％,千粒重增加1．6～5．2g;以300g／hm2在2月下旬和3月中旬喷雾两次,侵茎率相对防效达到99．3％～100％。     

A novelstreptomyces species for controlling plant-parasitic nematodes

A novel species ofSteptromyces isolated from nematode suppressive soils in Costa Rica was evaluated for efficacy in controlling plant-parasitic nematodes. This isolate, designated CR-43, was shown to inhibit reproduction ofCaenorhabditis elegans in a laboratory assay. Greenhouse trials utilizing three different methods of treatment with CR-43 gave significant reductions of tomato root galling due toMeloidogyne incognita. In a field experiment in Puerto Rico, in soil naturally infested withM. incognita, CR-43-treated pepper showed significant reductions in root galling and significant increases in yield as compared to untreated controls. In a second experiment in Puerto Rico, a significant reduction in tomato root galling and a slight reduction in root galling on pepper occurred. In this trial, yields on both tomato and pepper were higher in CR-43 treatments, but these differences were not statistically significant. In both experiments populations ofRotylenchulus reniformis were reduced by CR-43 treatment. In a field trial on strawberry in Massachusetts, CR-43-treated plants had lower numbers ofPratylenchus penetrons within roots and showed a significant decrease in black root rot disease. Studies on sterile filtrates from CR-43 cultures indicated that a major determinant of CR-43 antinematodal activity was mostly thermostable macromolecules of molecular weight higher than 6000. Culture filtrates of CR-43 exhibited antifungal activity in vitro.     

A Novel Antifungal Furanone from Pseudomonas aureofaciens, a Biocontrol Agent of Fungal Plant Pathogens

Pseudomonas aureofaciens (= P. chlororaphis) strain 63-28 is a biocontrol agent active against many soil-borne fungal plant pathogens and shows antifungal activity in culture assays. 3-(1-Hexenyl)-5-methyl-2-(5H)furanone was isolated from culture filtrates of this bacterium. The purified furanone showed antifungal activity against Pythium ultimum, Fusarium solani, Fusarium oxysporum, and Thielaviopsis basicola. The ED₅₀S for spore germination of these fungi were 45, 54, 56, and 25 g/ml, respectively. The compound also inhibited the germ tube growth of Rhizoctonia solani growing from microsclerotia, with an ED₅₀ of 61 g/ml. The compound is the reduced form of furanones previously described from this bacterium: 3-(1-hexenyl)-5-hydroxy-5-methyl-2-(5H)-furanone and 3-(1-hexenyl)-5-hydroxymethyl-2-(5H)-furanone. This volatile antifungal furanone has structural similarity to other antifungal furanones produced by actinomycetes (Streptomyces spp.), fungi (Trichoderma harzianum), and higher plants (Pulsatilla and Ranuculus spp.). This is the first report of 3-(1-hexenyl)-5-methyl-2-(5H)-furanone produced by a bacterium.     

水杨酸衍生物的合成及生物活性测定

以水杨酸为起始原料,设计及合成了6个水杨酸衍生物,6个目标化合物结构由^1H NMR、MS和熔点确证．采用平皿生长速率法测定6个化合物对草坪褐斑病菌和对水稻纹枯病菌的抑制效果,所有化合物均表现出一定的抑菌活性．     

2-氯-N-苯基苯甲酰胺的合成及其抑菌活性研究

目的:合成2-氯-N-苯基苯甲酰胺,并测定其对水稻纹枯病菌(Rhizoctonia solani)和油菜菌核病菌(Scle-rotiua sclerotiorum)的抑菌活性。方法:以2-氯苯甲酰氯和苯胺为原料,采用酰卤的胺解法合成2-氯-N-苯基苯甲酰胺,并通过IR,1H NMR进行结构确认。以多菌灵为对照,采用平板生长速率法测定其对水稻纹枯病菌和油菜菌核病菌菌丝的抑制率。结果:2-氯-N-苯基苯甲酰胺对水稻纹枯病菌和油菜菌核病菌均有较好的抑菌活性,其抑制中浓度IC50分别为5.00,6.38 mg/L。结论:合成的2-氯-N-苯基苯甲酰胺为研究和开发高效、低毒、对非靶标生物安全的新型植物病原真菌农药奠定了较好基础。     

宁康霉素对植物病原真菌的抑制作用

宁康霉素是由海洋细菌BAC-9912发酵获得的生物农药,对多种植物病原真菌有良好的抑制作用。本研究发现宁康霉素强烈抑制玉米纹枯病菌和苹果轮纹病菌的菌丝,可使玉米纹枯病菌菌丝枯萎和产生畸形。比较宁康霉素与农利灵和速克灵对玉米纹枯病菌的抑菌效果,结果显示宁康霉素的抑菌效果优于两种化学农药。