Mycorrhizal Application as a Biocontrol Agent against Common Root Rot of Barley

This study was conducted to assess the biocontrol efficacy of vesicular arbuscular mycorrhizae (VAM) against barley common root rot caused by Cochliobolus sativus. Mycorrhization of barley was achieved by growing the plants in expanded clay mixed with 10% (v/v) VAM fungus inoculum in pots experiments. Large differences in disease reactions were observed among genotypes and among treatments. VAM treatments significantly reduced the percentage of disease severity in infected barley plants and increased significantly root biomass, which could be attributed to enhanced nutrients uptake, via an increase in the absorbing surface area. It can be concluded that the application of VAM as a biocontrol agent played an important role in plant resistance and exhibit greater potential to protect barley plants against C. sativus

Detecting network attacks model based on a convolutional neural network

Due to the increasing use of networks at present, Internet systems have raised many security problems, and statistics indicate that the rate of attacks or intrusions has increased excessively annually, and in the event of any malicious attack on network vulnerabilities or information systems, it may lead to serious disasters, violating policies on network security, i.e., “confidentiality, integrity, and availability” (CIA). Therefore, many detection systems, such as the intrusion detection system, appeared. In this paper, we built a system that detects network attacks using the latest machine learning algorithms and a convolutional neural network based on a dataset of the CSE-CIC-IDS2018. It is a recent dataset that contains a set of common and recent attacks. The detection rate is 99.7%, distinguishing between aggressive attacks and natural assertiveness

Transcriptome profile of early responsive genes in susceptible barley during Rhynchosporium secalis infection

Scald caused by Rhynchosporium secalis, is an economically important disease found worldwide. In order to profile genes and pathways responding to R. seclais infection, leaf transcriptomes before and after fungus inoculation in susceptible barley were compared using cDNA-AFLP technique. Transcriptional changes of 144 expressed sequence tags (ESTs) were observed, of which 18 have no previously described function. Functional annotation of the transcripts revealed a wide range of pathways including cell wall fortification, cytoskeleton construction and metabolic processes at different time points. Furthermore, the results of RT-PCR analysis on candidate genes, ABC transporters and lycine-specific demethylase were consistent with the cDNA-AFLP data in their expression patterns. Taken together, our data suggest that susceptible barley reprograms metabolic and biological processes to initiate a suitable response R. secalis infection

Salicylic acid and hydrogen peroxide accumulation in relation to hydrolyte leakage in barley plants challenged with Cochliobolus sativus

Spot blotch (SB) caused by the hemibiotrophic fungal pathogen Cochliobolus sativus is a destructive disease of barley worldwide. To better understand the mechanisms of resistance to this disease, the involvements of salicylic acid (SA), hydrogen peroxide (H2O2) and ion fluxes during the interaction between resistant and susceptible barley seedlings and C. sativus were investigated. Early SA accumulation in leaf tissues was accompanied with an increase in H2O2 concentration in both compatible and incompatible interactions. The resistant cultivar constitutively contained higher levels of H2O2 and SA, as well as during the 72 h as compared with the un-infected control (0 h). However, levels increased rapidly upon infection in both cultivars. Moreover, a markedly greater increase in ion fluxes from the compatible material compared with the incompatible one was observed. Results suggest that SA and H2O2 accumulation are important during both compatible and incompatible barley- C. sativus interactions

Changes in PR2 and PAL Patterns in Barley Challenged with Leaf Stripe (Pyrenophora graminea) and Powdery Mildew (Blumeria graminis) Diseases

The seed-borne (Pyrenophora graminea; Pg) and foliar (Blumeria graminis; Bg) are two economically important fungal pathogens of barley worldwide. Barley plant resistance genes, as the pathogenesis related proteins play an important role in defense mechanisms. This study aimed to monitor the expression of PR2 and PAL pathogenesis related genes during compatible/incompatible barley interaction with Pg and Bg at different time points of disease development using the Quantitative Real-time PCR technique (qRT-PCR). Comparison of data showed that PR2 and PAL were significantly over expressed in infected resistant and susceptible plants as against their lower expression in controls,. Upregulation of these defense-related genes during Pg and Bg infections was companied with a slow development of disease symptoms at the time course in the resistant genotype. qRT-PCR analysis revealed higher gene expression in resistant barley plants inoculated with Pg as compared with Bg, with a maximum expression for PR2 (13.8 and 5.06-fold) and PAL (14.8 and 4.51-fold) respectively, at the latest stage of each disease development. It was also noteworthy that PR2 and PAL genes, had higher constitutive expression and faster induction for the both pathogens in the resistant genotype as compared with the susceptible one. Obtained results suggest that both genes, PR2 and PAL, positively regulate Pg- and Bg-resistance in barley plants during disease progress. These expression patterns can provide useful insights to better understanding of the barley–fungus interactions with different fungal lifestyles

Diallel Analysis of Barley Resistance to Blumeria graminis

Powdery mildew, caused by Blumeria graminis f. sp. hordei (Bgh) is a common foliar disease of barley worldwide. The creation of new cultivars with durable resistance to Bgh is highly desirable. This work was undertaken to examine the resistance to Bgh in 10 genetically diverse barley parents, and to evaluate their general combining ability (GCA) and specific combining ability (SCA) effects toward determining the genetic basis of disease resistance. Two experiments, in a growth chamber on seedling and in the field on adult plant stages, were conducted using a randomized complete block design with three replicates. The parents expressing differences in their reactions to Bgh were crossed in a half-diallel mating design to generate 45 full-sib families. Genetic component analysis showed significant effects for both GCA and SCA under both experiments suggesting that additive as well as non-additive genetic mechanisms were involved in the expression of resistance in these parents. The estimate of narrow-sense heritability was 0.63 and broad-sense heritability was 98% indicating that selection for the disease resistance should be effective in these crosses. Resistant parents ‘Banteng, PK 30-136 and ‘Igri’ had significantly negative GCA effects, suggesting their prime suitability for use in barley breeding programs to improve resistance to Bgh

Screening of barley breeding lines for resistance to common root rot disease through incidence and severity parameters

Cochliobolus sativus, the causal agent of common root rot (CRR), is a devastating fungal pathogen of barley that can cause significant yield losses worldwide. The development of resistant cultivars has proven difficult, therefore, in this work, CRR-resistant barley germplasm was developed by crossing three resistant-by-susceptible cultivars currently used in Europe and West Asia. Following greenhouse evaluations of 150 doubled haploid lines derived from these crosses, 40 lines were evaluated under artificial infection conditions using incidence and severity parameters during two consecutive seasons. Data showed significant differences among barley lines with a continuum of resistance levels ranging from highly susceptible to resistant which were consistent in both seasons. However, five promising lines had slightly lower CRR disease than the others. Additionally, significant differences (P <0.05) in mean incidence and severity values were found among lines, with values being consistently higher in the susceptible ones. However, CRR severity increased linearly as incidence increased in both seasons. All together, the present study suggests that, the newly identified resistance lines can serve as potential donors for ongoing CRR resistance breeding program to generate high-yielding commercial barley cultivars, and that the positive correlation between CRR parameters I and S may be beneficial for many types of studies on this disease

Characterization of barley germplasm for leaf stripe (Pyrenophora graminea) resistance based on incidence and severity parameters

Barley leaf stripe (BLS) caused by Pyrenophora graminea is an important seed-borne disease of barley causing significant yield and quality losses worldwide. The development of resistant cultivars has proven difficult, therefore, in this work, BLSresistant barley germplasm was developed by crossing six barley cultivars currently used in Europe and West Asia. Out of 270 doubled haploid lines derived from these crosses, 40 lines were evaluated under field artificial infection conditions using incidence (I; proportion of diseased plants) and severity (S; proportion of infected leaf area per plant). Disease resistance parameters showed a broad range of variation in mean I and S values with a continuum of resistance levels ranging from highly susceptible to highly resistant with values being consistently higher in the susceptible ones. However, eight promising resistant lines with high yield per plant were identified. Moreover, BLS severity increased linearly as incidence increased (r = 0.76, P < 0.001). This work suggests that BLS resistance sources identified in this study can be used for further genetic analysis and introgression for varietal improvement, and that the positive correlation between I and S parameters may be beneficial for many types of studies on this disease

Evaluation of Xylanase Production from Filamentous Fungi with Different Lifestyles

Xylanase plays an important role in the food, feed, and pulp/paper industry. Filamentous fungi have been considered as useful producers of this enzyme from an industrial point of view, due to the fact that they excrete xylanases into the medium. In this study, four fungal species belonging to different genera, i.e. Aspergillus, Cochliobolus, Pyrenophora, and Penicillium were isolated from different sources and compared for their ability to produce xylanase in submerged culture. The fungal species showed enzyme activity as determined by dinitrosalicylic acid (DNS) method. It was found that the two saprophytic Aspergillus strains, i.e A. terreus (Fss 129) and A. niger (SS7) had the highest xylanase activity of 474 and 294 U ml–1 at pH 7 and 8, respectively, in the presence of corn cob hulls after 120 h of incubation. The production of xylanase seemed to be strongly influenced by the interactive effect of initial pH on the fungi. Interestingly, xylanase was better produced by the saprophytic fungi of Aspergillus and Penicillium than by the plant pathogenic ones of Cochliobolus and Pyrenophora. This work provides additional information to support future research on fungi with different lifestyles for food industrial production of xylanase

Changes in transcript and protein expression levels in the barley — Cochliobolus sativus interaction

Spot blotch, caused by Cochliobolus sativus, is an important barley disease which causes extensive grain yield losses worldwide. In order to investigate the molecular responses to the C. sativus infection, leaf transcriptome and proteome before and after fungus inoculation in a resistant barley genotype, were compared using cDNA-AFLP and 2-D PAGE techniques. A notable number of transcripts and proteins exhibiting significant differential accumulations were detected compared to the non-inoculated controls. Functional annotation of the transcripts and proteins revealed a wide range of pathways including cell wall fortification, metabolism, signal transduction and defence. Spearman correlations of the relative abundances for those genes represented by both an mRNA and a protein showed a weak (rs = 0.4; P < 0.001) relationship, indicating that post-transcriptional processes play a critical role in regulating the protein level during infection. Taken together, our study suggested that a joint analysis of the transcriptomic and proteomic of barley data can provide useful insights that may not be deciphered from individual analysis of mRNA or protein expressions