Knock-out of BnHva22c reduces the susceptibility of Brassica napus to infection with the fungal pathogen Verticillium longisporum

Verticillium longisporum(Vl43)is a soilborne hemibiotrophic fungal pathogen causing stem striping on oilseed rape(OSR)and severe yield losses.Breeding for resistant varieties is the most promising approach to control this disease.Here,we report the identification of Hva22c as a novel susceptibility factor and its potential for improving OSR resistance.Hva22c is a member of the Hva22 gene family,originally described for barley(Hordeum vulgare).Several Hva22 members have been located at the endoplasmic reticulum.Hva22c is up-regulated in response to Vl43 in both Arabidopsis and OSR.We demonstrate that knock-out of Hva22c in OSR by CRISPR/Cas9 and its homolog in Arabidopsis by T-DNA insertion reduced plants’susceptibility to Vl43 infection and impaired the development of disease symptoms.To understand the underlying mechanism,we analysed transcriptomic data from infected and non-infected roots of hva22c knock-out and wild type plants.We identified a homozygous mutant with frame-shifts in all four BnHva22c loci displaying a vastly altered transcriptional landscape at 6 dpi.Significantly,a large set of genes was suppressed under mock conditions including genes related to the endomembrane systems.Among the up-regulated genes we found several defense-related and phytohormone-responsive genes when comparing mutant to the wild type.These results demonstrate that Hva22c is functionally required for a fully compatible plant-fungus interaction.Its loss of function reduces plant susceptibility,most likely due to endoplasmatic reticulum and Golgi dysfunction accompanied by additionally activated defense responses.These findings can help improve OSR resistance to V.longisporum infection.

Maize straw application as an interlayer improves organic carbon and total nitrogen concentrations in the soil profile: A four-year experiment in a saline soil

Soil salinization is a critical environmental issue restricting agricultural production.Deep return of straw to the soil as an interlayer (at 40 cm depth) has been a popular practice to alleviate salt stress.However,the legacy effects of straw added as an interlayer at different rates on soil organic carbon (SOC) and total nitrogen (TN) in saline soils still remain inconclusive.Therefore,a four-year (2015–2018) field experiment was conducted with four levels (i.e.,0,6,12and 18 Mg ha~(–1)) of straw returned as an interlayer.Compared with no straw interlayer (CK),straw addition increased SOC concentration by 14–32 and 11–57%in the 20–40 and 40–60 cm soil layers,respectively.The increases in soil TN concentration (8–22 and 6–34%in the 20–40 and 40–60 cm soil layers,respectively) were lower than that for SOC concentration,which led to increased soil C:N ratio in the 20–60 cm soil depth.Increases in SOC and TN concentrations in the 20–60 cm soil layer with straw addition led to a decrease in stratification ratios (0–20 cm:20–60 cm),which promoted uniform distributions of SOC and TN in the soil profile.Increases in SOC and TN concentrations were associated with soil salinity and moisture regulation and improved sunflower yield.Generally,compared with other treatments,the application of 12 Mg ha~(–1) straw had higher SOC,TN and C:N ratio,and lower soil stratification ratio in the2015–2017 period.The results highlighted that legacy effects of straw application as an interlayer were maintained for at least four years,and demonstrated that deep soil straw application had a great potential for improving subsoil fertility in salt-affected soils.

Enemies atpeace:Recentprogressin Agrobacterium-mediated cereal transformation

Agrobacterium tumefaciens mediated plant transformation is a versatile tool for plant genetic engineering following its discovery nearly half a century ago.Numerous modifications were made in its application to increase efficiency,especially in the recalcitrant major cereals plants.Recent breakthroughs in transformation efficiency continue its role as a mainstream technique in CRISPR/Cas-based genome editing and gene stacking.These modifications led to higher transformation frequency and lower but more stable transgene copies with the capability to revolutionize modern agriculture.In this review,we provide a brief overview of the history of Agrobacterium-mediated plant transformation and focus on the most recent progress to improve the system in both the Agrobacterium and the host recipient.A promising future for transformation in biotechnology and agriculture is predicted.

Antimicrobial Activity of Wild Plant Seed Extracts against Human Bacterial and Plant Fungal Pathogens

Five wild plant species belonging to different families (Chenopodium album, Plantago major, Elytrigia elongata, Filipendula ulmaria and Nigella sativa) widely spread in Russian Federation and the former USSR were evaluated for their ability to inhibit growth of two important human food-borne pathogens (Escherichia coli O157:H7 and Listeria monocytogenes strain EGD-e) and eight plant pathogens (Alternaria alternata, Alternaria tenuissima, Bipolaris sorokiniana, Stagonospora nodorum, Fusarium solani, Fusarium oxysporum, Fusarium culmorum and Phytophtora infestans). To isolate biologically active compounds from seeds, a step-wise procedure including extraction with hexane, ethyl acetate, ethanol, and 10% acetic acid followed by reversed-phase HPLC was developed. Using disc-diffusion assay, the highest activity against E. coli O157:H7 was observed with extracts from F. ulmaria (hexane and ethyl acetate extracts and the unbound RP-HPLC fraction) and P. major (ethyl acetate extract and the unbound RP-HPLC fraction);E. elongate (the unbound RP-HPLC fraction) was less active. The extracts from P. major and E. elongate (the unbound RP-HPLC fractions) were equally highly active against L. monocytogenes, while those of F. ulmaria (the unbound RP-HPLC fraction) and N. sativa (hexane and ethyl acetate extracts) were less active against this pathogen. The dynamics of L. monocytogenes EGD-е and E. coli O157:H7 growth in the presence of two most potent extracts (RP-HPLC-unbound fractions of P. major and E. elongate and the hexane extract of F. ulmaria) was studied.

Agro-Landscape Zoning of West Georgia for Spreading New Varieties of Tangerine in Order to Reveal Optimal Natural Conditions

A landscape-multifactor method has been developed and established in West Georgia for agroresource potential spatial distribution regularities for Tangerine. The emphasis was made especially for the components (relief, climate, soils), having substantial impact on the growth and yield of citrus. Morpho-metric analysis (biometric indicators, end of fetal maturity, starting of maturity, frost resistance, etc.) of frost resistant Tangerine-Tiakhara Unshiu from Japan and Saadreo and Adreula (Early ripe) has been conducted. For the application of landscape multifactor (multi-component) method, which takes into account the role of each component in the spread of citrus, the most important parameters are the following: relief (dismemberment, slope, aspect), climate (temperature inversions, sum of active temperatures, hydrothermal coefficient, etc.), soil conditions. Using this method and morphometric analysis, it became possible ranking of frost resistant tangerine (GIS-technologies) based on the landscape, the result of which has been determined that the frost resistant tangerine varieties in western Georgia has a high yield in the higher subtropical zone.

Ranking of Feijoa (FEIJOA Sellowiana) in Subtropical Humidified Zone of Adjara and Forest Ecosystem by Multiple-Factor Approach

It was elaborated a method of agro-ecosystem ranking for feijoa culture and forest ecosystem in one of regions of Western Georgia—Adjara subtropical humidified zone. On the basis of mineralogical and morphometric analysis (biometric parameters, beginning and end of growth, beginning of fruit ripening and mass ripening, frost resistance etc.) of feijoa culture (Feigoa selliowiana) and by multiple-factor approach we have evaluated culture’s rational disposition and optimal environment for development of land. The main accent was made on geomorphological (relief, inclination, exposition) and agro-climatic (sum of active temperatures, hydrothermal coefficient, temperature conditions, physical and chemical features of soil) factors. As a result of implemented zoning a landscape zone with agricultural resources potential and hypsometrical levels optimal for development of feijoa culture was revealed. During the research we also revealed corresponding agro-eco- system zone, compatible with feijoa zone, evaluation of quality of forest land and determination of ecosystem and its indicating character. For determination of compatibility of feijoa plants and distribution of forest ecosystem we have created a map of large-scale ecosystems and geo-information system. By Cartometric and geographic-informational analysis, it became possible to find information about types of forest ecosystems, areas occupied by them and their share in researched zone.

多位点生物杀虫毒素BtA形成的HPLC分析

基于多位点生物杀虫毒素理论和生物耦合技术,研制生物杀虫毒素BtA,为新生物农药的开发提供了一种新思路、新方法和新手段。将苏云金芽孢杆菌(B.t.)晶体进行酶解改造,形成带末端氨基的原毒素;将阿维菌素的羟基进行激活、衍生化,形成带羧基的阿维菌素衍生物(Abamectin-COONa);再利用氨基-羧基偶联剂(EDC)进行两种生物毒素的生物耦合。利用反相液相色谱(HPLC)检测不同反应时间的BtA生物耦合体系,以确定生物耦合反应的发生;通过反应底物两两组合的分析比较,识别生物耦合产物BtA生成的色谱特征,分析生物耦合产物---多位点生物杀虫毒素BtA的产生过程。

禾谷缢管蚜在越冬寄主植物上的行为研究

通过室内饲养观察、田间调查和利用微型昆虫显微摄影技术,研究了禾谷缢管蚜越冬卵在越冬寄主稠李(Prunus padis)上孵化,干母、干雌取食、生长发育和繁殖等行为过程,以及形态和体色变异特点。结果表明,禾谷缢管蚜越冬卵在室内的孵化率为88.68％-92.51％;在德国北部吕贝克附近田间孵化率为24.2％。越冬卵孵化起点温度低于4℃。在室温22℃下卵孵化历期为5-7 d,孵化高峰在卵孵化始期后第3-4天。一日内最佳孵化时间在05:00-07:30。在室内饲养条件下,将越冬卵孵化的干母直接移植到麦苗上,蚜虫几乎都不能存活。

The static and cidal effects of veterinary antibiotics on soil microorganisms in the presence of organic and mineral amendments

●Gentamicin initially decreased microbial activity comparative to penicillin higher.●Recovery was comparatively high in oxytetracycline treated soils.●Organic amendments improved the resilience indices.●Unexpectedly the qCO_(2) decreased in the antibiotic treated soils.●The static effects of the applied antibiotics were higher than their cidal effects.This study aimed to describe the static and cidal adverse effects of antibiotics on soil microbial activity resulting from manure application.So,in the present study,the treatments included:without antibiotics;application of gentamicin,oxytetracycline,and penicillin each in different concentrations(50,100,and 200 mg kg−1 dry soil).They were applied in soils treated with and without organic and mineral conditioners(cow manure,biochar,and nano-zeolite).Soil microbial respiration and metabolic quotient were studied at three time periods(1−7,7−30,and 30−90 days)during a 90-day incubation of the treated soils.Antibiotics applied to the soil samples significantly decreased soil basal respiration(BR)values compared to those of the control,and the most significant decrease was observed for gentamicin.Gentamicin had a short intensive impact,alleviated by manure and biochar,on soil copiotrophs.After a significant initial reduction in substrate-induced respiration(SIR),gentamicin application then caused a substantial increase in SIR values.Unexpectedly metabolic quotient decreased in the antibiotic-treated soils.This study revealed that the static effects of the applied antibiotics in soil were greater than the cidal effects.

Evolutionary ecology of microsporidia associated with the invasive ladybird Harmonia axyridis

Invasive species are characterized by the rapid growth and spread of their populations after establishing a foothold in new habitats, and there are now many examples of such species negatively affecting biodiversity and the economy. It is unclear why some species can become successful invaders, whereas most （even if closely related） remain noninvasive. We previously proposed a hypothesis that parasites associated with invading species can promote their invasive success if they are harmless toward the invaders but harmful to their competitors and/or predators in the newly colonized habitat. Here we discuss whether microsporidia that have recently been discovered in the invasive ladybird Harmonia axyridis contribute to its invasive success. We show that all H. axyridis beetles sourced from diverse collection sites all over the world carry abundant microsporidia. This suggests that both native and invasive H. axyridis populations are associated with these tolerated parasites, which were likely to have existed in native populations before expansion rather than being acquired in newly colonized areas. We describe the pathogenesis of the microsporidia during different developmental stages of H. axyridis and we address the possibility that the predation of its infected eggs and larvae by competing native ladybird species may lead to their infection and ultimately to their decline. Finally, we discuss our initial hypothesis： microsporidia that are tolerated by an invasive vector insect can be active against susceptible native competitors and/or predator species.

Development and testing of a weather-based model to determine potential yield losses caused by potato late blight and optimize fungicide application

Late blight is one of the most important potato diseases. To minimize yield losses, various protective measures are used including fungicide application. Active use of fungicides results in a contamination of the environment. Therefore, crop protection strategies optimizing the number of treatments are of great interest.Using information about late blight development in an experimental potato field recorded over 30 seasons, a simulator to forecast yield losses caused by the disease was developed based on the number of 5-d periods favorable for reinfection of plants during a vegetation season. The simulator was successfully verified using independent data on the disease development from nine unprotected potato fields in the Netherlands and Germany. The average difference between the calculated and real yield losses did not exceed 5%. Using the simulator and weather data for a period of 2007–2017, yield losses were calculated for several areas of the Bryansk, Tambov, and Orenburg Regions of Russia. The results revealed differences in disease development between these regions and may be used to develop recommendations for a frequency of fungicide applications according to the regional risk of epidemics, leading to a significant reduction in fungicide use.