Project description:Wheat streak mosaic virus (WSMV) and Triticum mosaic virus (TriMV) are type members of Tritimovirus and Poacevirus genera, respectively, in the family Potyviridae, and are transmitted by wheat curl mites. Co-infection of these two viruses causes synergistic interaction with increased virus accumulation and disease severity in wheat. In this study, we examined the effects of synergistic interaction between WSMV and TriMV on endogenous small (s) RNAs and virus-specific small interfering RNAs (vsiRNAs) in susceptible (Arapahoe) and temperature-sensitive resistant (Mace) wheat cultivars at 27C and 18C. Single- and double-infections in wheat caused a shift in the profile of endogenous sRNAs from 24 nt being the most predominant in healthy plants to 21 nt in infected wheat. Additionally, we report high-resolution vsiRNA maps of WSMV and TriMV in singly- and doubly-infected wheat cultivars Arapahoe and Mace at 18C and 27C. Massive amounts of 21 and 22 nt vsiRNA reads were accumulated in Arapahoe at both temperatures and in Mace at 27C but not at 18C. The plus- and minus-sense vsiRNAs were distributed throughout the genomic RNAs in Arapahoe at both temperature regimens and in Mace at 27C, although some regions of genomic RNAs serve as hot-spots with an excessive number of vsiRNAs. The positions of vsiRNA peaks were conserved among wheat cultivars Arapahoe and Mace, suggesting that Dicer-like enzymes of susceptible and resistant wheat cultivars are similarly accessed the genomic RNAs of WSMV and TriMV. Additionally, several cold-spot regions were found in the genomes of TriMV and WSMV with no or a few vsiRNAs, indicating that certain regions of WSMV and TriMV genomes are not accessible to Dicer-like enzymes. The high-resolution map of endogenous and vsiRNAs from wheat cultivars synergistically infected with WSMV and TriMV at two temperature regimens form a foundation for understanding the virus-host interactions, effect of synergistic interactions on host defense mechanisms, and virus resistance mechanisms in wheat. Small RNA was sequenced from two wheat cultivars (Mace and Araphahoe), at two temperatures 18C and 27C, for healthy (control/uninfected), infected with wheat streak mosaic virus (WSMV), infected with Triticum mosaic virus (TriMV), and a double-infecttion of WSMV and TriMV.
Project description:Wheat streak mosaic virus (WSMV) and Triticum mosaic virus (TriMV) are type members of Tritimovirus and Poacevirus genera, respectively, in the family Potyviridae, and are transmitted by wheat curl mites. Co-infection of these two viruses causes synergistic interaction with increased virus accumulation and disease severity in wheat. In this study, we examined the effects of synergistic interaction between WSMV and TriMV on endogenous small (s) RNAs and virus-specific small interfering RNAs (vsiRNAs) in susceptible (Arapahoe) and temperature-sensitive resistant (Mace) wheat cultivars at 27ºC and 18ºC. Single- and double-infections in wheat caused a shift in the profile of endogenous sRNAs from 24 nt being the most predominant in healthy plants to 21 nt in infected wheat. Additionally, we report high-resolution vsiRNA maps of WSMV and TriMV in singly- and doubly-infected wheat cultivars Arapahoe and Mace at 18ºC and 27ºC. Massive amounts of 21 and 22 nt vsiRNA reads were accumulated in Arapahoe at both temperatures and in Mace at 27ºC but not at 18ºC. The plus- and minus-sense vsiRNAs were distributed throughout the genomic RNAs in Arapahoe at both temperature regimens and in Mace at 27ºC, although some regions of genomic RNAs serve as hot-spots with an excessive number of vsiRNAs. The positions of vsiRNA peaks were conserved among wheat cultivars Arapahoe and Mace, suggesting that Dicer-like enzymes of susceptible and resistant wheat cultivars are similarly accessed the genomic RNAs of WSMV and TriMV. Additionally, several cold-spot regions were found in the genomes of TriMV and WSMV with no or a few vsiRNAs, indicating that certain regions of WSMV and TriMV genomes are not accessible to Dicer-like enzymes. The high-resolution map of endogenous and vsiRNAs from wheat cultivars synergistically infected with WSMV and TriMV at two temperature regimens form a foundation for understanding the virus-host interactions, effect of synergistic interactions on host defense mechanisms, and virus resistance mechanisms in wheat.
Project description:The economic importance of wheat and its contribution to human and livestock diets has been already demonstrated. However, wheat production is impacted by pests that induce yield reductions. Among these pests, wheat curl mite (WCM, Aceria tosichella Keifer) impacts wheat all around the world. WCM are tiny pests that feed within the whorl of developing leaves and prevent the leaves from unfurling by causing leaves curling. The curling of the leaves provides a protective niche for the WCM. Additionally, WCM are also the vector of serious viruses in wheat. Little is known regarding the impact of the WCM on wheat transcriptome, and to date, only one article has been published describing the wheat transcriptomic changes after 1 day of WCM feeding. To better understand the wheat transcriptome variation after long-term feeding by WCM (10 days post infestation (dpi)), we used an RNA-seq approach. We collected leaves uninfested and infested with WCR from two wheat cultivars: Byrd (WCM resistant) and Settler CL (WCM susceptible) at 10 dpi. Our transcriptomic analysis revealed the common and specific transcriptomic variations in WCM resistant and susceptible wheat cultivars, chromosome specific location of the differentially expressed genes, and also identified the gene functions and pathways involved in WCM resistance. Collectively, our study provides important insights on wheat defense mechanisms against WCM after long-term feeding.
Project description:Millet is a dangerous weed in Hungary. Lack of seed dormancy helps it to spread easily and be present at maize, wheat and other crop fields. Our previous report revealed the possibility that millet can also play a role as a virus reservoir. In that study we detected the presence of several viruses in millet using DAS ELISA. Because serological methods can only detect the presence of the investigated particular pathogens, we suspected that other, previously unknown viruses can also be present in this weed. To investigate this theory, we randomly sampled two locations and collected millets showing stunting, chlorosis, and striped leaves and investigated the presence of viruses using small RNA HTS as a diagnostic method. Our result confirmed the widespread presence of wheat streak mosaic virus at both locations. Moreover, barley yellow striate mosaic virus and barley virus G were also identified, which have not been described from Hungary before. As these viruses can cause severe diseases on wheat, their presence on a weed mean a potential infection risk. Our study indicates that the presence of millets on the fields needs a special control in order to prevent emergence of new diseases at crop fields.
Project description:During a proof-of-concept study, virome of millet, grown as weed was determined by small RNA HTS. As a result, from the pools of 20 randomly collected millet samples collected at two locations, we identified the presence of three viruses, two of them first time in Hungary. Based on our results we could only suspect that these viruses: wheat streak mosaic virus (WSMV), barley stripe mosaic virus (BYSMV) and barley virus G (BVG) could have been overwintered in millet or other monocotyledonous weeds growing at these fields. As a follow-up research, in the summer of 2021, we collected symptomatic leaves of several monocotyledonous plants at the same fields. This time the sampling was done in July. From the samples, small RNA HTS was carried out.
2024-10-02 | GSE270076 | GEO
Project description:Characterizing wheat defense mechanisms against wheat curl mite infestation
Project description:Background Maintaining global food security in the context of climate changes is an important challenge in the next century. Improving abiotic stress tolerance of major crops, like wheat, can contribute to this goal. Therefore, new genes improving tolerance to abiotic stresses, like drought, are needed to support breeding programs aimed at producing more adapted cultivars. Recently, we screened five wheat Zinc Finger Proteins (TaZFPs) and identified TaZFP13D as a new gene improving water-stress tolerance. However, a more detailed characterization of this gene is required to better evaluate its potential in drought tolerance and to decipher the underlying molecular basis. Results We used the Barley Stripe Mosaic Virus to up- or down-regulate TaZFP13D expression in wheat. Overexpression of TaZFP13D under well-watered conditions enhances growth as indicated by improved biomass. Exposing plants to a severe drought stress revealed that TaZFP13D strongly increases survival rate and stress recovery. In addition, TaZFP13D reduces drought-induced oxidative damages, at least in part by improving key antioxidant enzymes activity. Conversely, down-regulation of TaZFP13D decreases drought tolerance and protection against drought-induced oxidative damages. RNA-seq-based transcriptome analysis showed that many genes regulated by TaZFP13D were previously shown to improve drought tolerance, while many others are related to the photosynthetic electron transfer chain and are proposed to improve photosynthesis efficiency and chloroplast protection against ROS damages. Conclusion This study highlights the important role of TaZFP13D in wheat drought tolerance, contributes to unravel the complex regulation governed by TaZFPs, and provides a useful marker to select more drought tolerant wheat cultivars.
Project description:Abstract Background Drought stress is one of the major factors limiting wheat production globally. Improving drought tolerance is important for agriculture sustainability. Although various morphological, physiological and biochemical responses associated with drought tolerance have been documented, the molecular mechanisms and regulatory genes that are needed to improve drought tolerance in crops require further investigation. We have used a novel 4-component version (for overexpression) and a 3-component version (for underexpression) of a barley stripe mosaic virus-based (BSMV) system for functional characterization of the C2H2-type zinc finger protein TaZFP1B in wheat. These expression systems avoid the need to produce transgenic plant lines and greatly speed up functional gene characterization. Results We show that overexpression of TaZFP1B stimulates plant growth and up-regulates different oxidative stress-responsive genes under well-watered conditions. Plants that overexpress TaZFP1B are more drought tolerant at critical periods of the plant’s life cycle. Furthermore, RNA-Seq analysis revealed that plants overexpressing TaZFP1B reprogram their transcriptome, resulting in physiological and physical modifications that help wheat to grow and survive under drought stress. In contrast, plants transformed to underexpress TaZFP1B are significantly less tolerant to drought and growth is negatively affected. Conclusions This study clearly shows that the two versions of the BSMV system can be used for fast and efficient functional characterization of genes in crops. The extent of transcriptome reprogramming in plants that overexpress TaZFP1B indicates that the encoded transcription factor is a key regulator of drought tolerance in wheat.