Disaccharide combinations and the expression of enolase3 and plasma membrane Ca2+ ATPase isoform in sturgeon sperm cryopreservation

Acipenser sinensis and Acipenser dabryanus are critically endangered species, so germplasm conservation via cryopreservation of sperm is necessary. Disaccharides can act as membrane‐impermeable cryoprotectants, and enolase3 (ENO3) and plasma membrane Ca²⁺ ATPase isoform (PMCA2) are proteins associated with sperm quality. We considered seven characteristics of sperm quality in cultured brood stock from A. sinensis and A. dabryanus. We tested use of sucrose or trehalose alone and in combination at different concentrations for cryopreservation of A. dabryanus sperm. A low concentration of sucrose plus trehalose (S₁₅T₁₅) was optimal. Mixing of the extender with sucrose, lactose, or trehalose alone or with pairwise mixtures revealed that a mixture of lactose and trehalose (L₁₅T₁₅) gave the best results for both A. sinensis and A. dabryanus. Enolase3 and PMCA2 expression levels were measured in cryopreserved A. sinensis sperm via Western blotting. Relative ENO3 and PMCA2 expression levels were examined, and the relationship between disaccharide composition, sperm quality and protein expression was explored in A. sinensis. The results showed that relative ENO3 and PMCA2 expression levels were the highest at L₁₅T₁₅ in cryopreserved A. sinensis sperm. There were significant positive correlations between ENO3 expression and percentage membrane integrity, and between PMCA2 expression and sperm motility parameters (percentage of motile sperm, curvilinear velocity, straight‐line velocity and average path velocity; p < .05) in cryopreserved A. sinensis sperm. Our results indicate the optimal disaccharide combination and concentrations for cryopreservation of A. sinensis and A. dabryanus sperm and suggest that ENO3 and PMCA2 expression levels could serve as a valuable indicator of sperm quality in A. sinensis.     

Multiple resistance of Papaver rhoeas L. to 2,4‐D and acetolactate synthase inhibitors in four European countries

The issue of cross‐ or multiple resistance to acetolactate synthase (ALS) inhibitors and the auxinic herbicide 2,4‐D was investigated in Papaver rhoeas L., a common and troublesome weed in winter cereals, in a broad‐scale study across four European countries. A combination of herbicide sensitivity bioassays and molecular assays targeting mutations involved in resistance was conducted on 27 populations of P. rhoeas originating from Greece (9), Italy (5), France (10) and Spain (3). Plants resistant to the field rate of 2,4‐D were observed in 25 of the 27 populations assayed, in frequencies ranging from 5% to 85%. Plants resistant to ALS‐inhibiting herbicides (sulfonylureas) were present in 24 of the 27 populations, in frequencies ranging from 4% to 100%. Plants resistant to 2,4‐D co‐occurred with plants resistant to sulfonylureas in 23 populations. In four of these, the probability of presence of plants with cross‐ or multiple resistance to 2,4‐D and sulfonylureas was higher than 0.5. ALS genotyping of plants from the field populations or of their progenies, identified ALS alleles carrying a mutation at codon Pro197 or Trp574 in 2,4‐D‐sensitive and in 2,4‐D‐resistant plants. The latter case confirmed multiple resistance to 2,4‐D and ALS inhibitors at the level of individual plants in all four countries investigated. This study is the first to identify individual plants with multiple resistance in P. rhoeas, an attribute rarely assessed in other weed species, but one with significant implications in designing chemical control strategies.     

吉林延龄草种子内源抑制物质初步研究

为探讨吉林延龄草种子内源抑制物质生理活性及种子中抑制物质的去除方法,采用乙酸乙酯、甲醇、水提取吉林延龄草种子并测定其提取物对白菜、水稻幼苗生长的抑制活性,用温水(25,35,45℃)浸种并测定各批次浸提液抑制活性,结果表明,吉林延龄草种子浸提液(乙酸乙酯提取液除外)对白菜幼根及胚轴,水稻幼根均有显著抑制作用,且抑制物质的活性随着提取物浓度的增加而增强,吉林延龄草种子水提取液(C)对白菜和水稻幼苗生长的抑制活性高于甲醇提取液(B)的生物活性,吉林延龄草种子乙酸乙酯提取液对白菜和水稻幼苗无显著抑制作用(p＞0.05),吉林延龄草种子经乙酸乙酯、甲醇溶液提取后,再经蒸馏水提取获得的水提液Ⅱ(E)对白菜和水稻幼苗生长的抑制活性减弱;温水浸泡可将其内源抑制物质浸提出来,且随着浸种时间的增加,浸提液对白菜幼根及胚轴的抑制作用呈现先增加而后逐渐降低的趋势.25℃蒸馏水浸泡种子第5天浸提液抑制作用达到最大,对白菜幼根及胚轴的抑制作用分别达到65.89％和25.69％,35℃蒸馏水浸泡种子第3天浸提液抑制作用达到最大,对白菜幼根及胚轴的抑制作用分别达到82.14％和59.93％,45℃蒸馏水浸泡种子第2天浸提液抑制作用达到最大,对白菜幼根及胚轴的抑制作用分别达到90.62％和83.86％.综合分析表明,吉林延龄草种子中存在活性较高的内源抑制物,用45℃温水浸泡可有效除去种子内源抑制物质.     

Comparative bioactivity of selected seed extracts from Brazilian Annona species and an acetogenin-based commercial bioinsecticide against Trichoplusia ni and Myzus persicae

The acute and chronic toxicity of ethanolic seed extracts from selected Brazilian Annona species (Annona montana Macfadyen, Annona mucosa Jacquin, Annona muricata Linnaeus, and Annona sylvatica A. St.-Hil) and an acetogenin-based commercial bioinsecticide (Anosom^®) were investigated against the cabbage looper Trichoplusia ni Hübner (Lepidoptera: Noctuidae) and the green peach aphid Myzus persicae (Sulzer) (Hemiptera: Aphididae). In the laboratory, extracts of A. mucosa and A. sylvatica as well as Anosom^® were especially active through oral and topical administration. A greenhouse trial showed that a formulated A. mucosa extract and Anosom^® were highly effective (>98% mortality) against third instar T. ni larvae, and comparable to a pyrethrin-based commercial insecticide (Insect Spray^®) used as a positive control. Similar to results with T. ni, A. mucosa extract showed the greatest aphicidal activity followed by A. sylvatica extract and Anosom^®. In another greenhouse trial, aphid population reduction from the formulated A. mucosa extract was superior to that provided by other treatments including the positive control. Though inferior to the A. mucosa extract, the acetogenin-based commercial insecticide (Anosom^®) and A. sylvatica extract also reduced aphid populations in a manner comparable to the positive control. Botanical insecticides based on these Annonaceae derivatives could be useful in the framework of Brassica IPM in Brazil and elsewhere, especially for organic production.     

Effects of natural protease inhibitors on high protease activity flours

Wheat grain damaged by wheat bug (Eurygaster spp.) contains the bug salivary secretion which hydrolyses the gluten needed for the dough quality of breadmaking due to its proteolytic activity. Since the protease inhibitors are widespread throughout the plant kingdom, the possibility of using some plants, especially food and feed legumes to decrease the proteolytic activity of flours milled from bug damaged wheats was investigated. The proteolytic activity was considerably inhibited by pefabloc-SC and EDTA-Na₂, suggesting that bug protease(s) included serine and metallo proteases. Extracts from cones of hops, seeds of grass pea, red kidney bean and sunflower caused reduction in the activity of bug protease(s). Effects of hop extract on electrophoretic, rheological properties of high protease activity flours milled from different bread wheat cultivars damaged by the bug were also studied. The dough development time and stability values of high protease activity flours increased considerably with hop extract at the lowest addition level (10:1, flour to hop extract ratio). The doughs supplemented with the hop extract had higher maximum resistance and lower extensibility values as compared to their controls. These results suggested that hop extract had improving effects on high protease activity flours due to the bug damage.     

改性尿素硝酸铵溶液调控氮素挥发和淋溶的研究

为了提高肥料的利用率,以尿素硝酸铵溶液为原料、聚氨酸为保护剂,复合抑制剂NBPT(N-丁基硫代磷酰三胺)和DMPP(3,4-二甲基吡唑磷酸盐)为材料,开发出改性尿素硝酸铵溶液(YUL1和YUL2),研究其对华北平原夏玉米追肥过程中的氨挥发和淋溶损失的调控效果。田间试验设置6个处理:不施氮肥(CK)、农民习惯追施尿素(CN)、优化追施尿素(CNU)、优化追施尿素硝酸铵溶液(UAN)、优化追施改性尿素硝酸铵溶液(YUL1)和优化追施改性尿素硝酸铵溶液(YUL2)。采用扫描电镜和能谱仪分析相关指标变化,在夏玉米喇叭口期追施氮肥后15d内进行田间原位连续动态观测氨挥发和土壤铵态氮和硝态氮变化,并在玉米成熟期测定产量,计算经济效益。结果表明,改性尿素硝酸铵溶液清澈无杂质,流延后成膜表面光滑、致密,抑制剂在膜表面分布均匀;能谱测试膜层表面磷硫含量增高,证明复合抑制剂与尿素硝酸铵溶液达到有效融合。在同等优化施氮量下:与CNU相比, YUL1氨挥发总量显著降低19.3%, YUL2增加9.6%;与UAN相比, YUL1、YUL2分别显著降低57.3%和42.0%。与其他施氮处理相比, YUL1和YUL2夏玉米季生长中后期0～20 cm土层依然保持相对较高的氮素含量水平,夏玉米收获后土壤硝态氮含量分别比CNU高46.0%和43.4%,比UAN高45.6%和44.7%;180～200cm土层硝态氮含量显著低于其他处理。在保证产量和净收益的同时,改性尿素硝酸铵肥料显著降低了氮素的氨挥发和淋溶损失浓度,尿酶抑制剂含量相对较高的YUL1抑制氨挥发的效果更好,硝化抑制剂含量相对高的YUL2硝态氮向下淋失的风险更小。     

Genetic basis and origin of resistance to acetolactate synthase inhibitors in Amaranthus palmeri from Spain and Italy

BACKGROUND

Amaranthus palmeri is an aggressive annual weed native to the United States, which has become invasive in some European countries. Populations resistant to acetolactate synthase (ALS) inhibitors have been recorded in Spain and Italy, but the evolutionary origin of the resistance traits remains unknown. Bioassays were conducted to identify cross-resistance to ALS inhibitors and a haplotype-based genetic approach was used to elucidate the origin and distribution of resistance in both countries.

RESULTS

Amaranthus palmeri populations were resistant to thifensulfuron-methyl and imazamox, and the 574-Leu mutant ALS allele was found to be the main cause of resistance among them. In two Spanish populations, 376-Glu and 197-Thr mutant ALS alleles were also found. The haplotype analyses revealed the presence of two and four distinct 574-Leu mutant haplotypes in the Italian and Spanish populations, respectively. None was common to both countries, but some mutant haplotypes were shared between geographically close populations or between populations more than 100 km apart. Wide genetic diversity was found in two very close Spanish populations.

CONCLUSION

ALS-resistant A. palmeri populations were introduced to Italy and Spain from outside Europe. Populations from both countries have different evolutionary histories and originate from independent introduction events. ALS resistance then spread over short and long distances by seed dispersal. The higher number and genetic diversity among mutant haplotypes from the Spanish populations indicated recurrent invasions. The implementation of control tactics to limit seed dispersal and the establishment of A. palmeri is recommended in both countries. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

昆虫取食和剪叶刺激对油松针叶内部分防御物质的诱导效应

为了研究自然条件下昆虫取食及剪叶刺激对油松诱导抗性的影响,本试验应用香草醛—盐酸法,亚硝酸钠—硝酸铝比色法以及紫外分光光度法,分析了剪叶和不同程度油松毛虫取食处理后,混交林和纯林中油松针叶内部分次生代谢物和蛋白酶抑制剂活性的动态变化。结果表明:剪叶及不同程度油松毛虫取食能够诱导缩合单宁、黄酮含量和胰蛋白酶抑制剂、胰凝乳蛋白酶抑制剂活性增加。与对照相比,胰凝乳蛋白酶抑制剂在混交林中的活性比纯林更为明显。说明剪叶及昆虫取食可诱导增加油松针叶内的缩合单宁和黄酮含量、提高胰蛋白酶抑制剂和胰凝乳蛋白酶抑制剂的活性,进而增强油松的抗虫性,林分类型可在一定程度上影响油松诱导防御物质的变化。     

Aggressiveness of Xanthomonas axonopodis pv. glycines isolates to soybean and hypersensitivity responses by other plants

Xanthomonas axonopodis pv. glycines ( Xag ) causes bacterial pustule disease which can significantly reduce the production of soybean. A collection of 26 isolates of Xag from different soybean-production areas of Thailand was shown to differ with regard to aggressiveness on soybean. They also differed in their ability to induce a hypersensitive response (HR) on four cultivars of tobacco and on other plant species including pepper, tomato, cucumber, pea and sesame. Tomato was most sensitive to HR induction by Xag . Isolate KU-P-34017 caused an HR on all the plant species tested. The minimal concentration of KU-P-34017 needed to induce HR on tobacco was approximately 5 × 10⁸ CFU mL⁻¹. A bacterium–plant interaction period of at least 2·5 h was necessary for HR, and different temperatures, relative humidity and light periods did not affect HR development. Inhibitors of eukaryotic metabolism, including cobalt chloride, lanthanum chloride and sodium orthovanadate (completely), and cycloheximide (partially) blocked the HR on tobacco, indicating the association of an active plant response. In contrast, the HR on tomato was inhibited only by cobalt chloride.