Wheat Roots Research Articles

Nitric Oxide Induces Autophagy in Triticum aestivum Roots.

Autophagy is a highly conserved process that degrades damaged macromolecules and organelles. Unlike animals, only scant information is available regarding nitric oxide (NO)-induced autophagy in plants. Such lack of information prompted us to study the roles of the NO donors' nitrate, nitrite, and sodium nitroprusside in this catabolic process in wheat roots. Furthermore, spermine, a polyamine that is found in all eukaryotic cells, was also tested as a physiological NO donor. Here, we show that in wheat roots, NO donors and spermine can trigger autophagy, with NO and reactive oxygen species (ROS) playing signaling roles based on the visualization of autophagosomes, analyses of the levels of NO, ROS, mitochondrial activity, and the expression of autophagic (ATG) genes. Treatment with nitrite and nitroprusside causes an energy deficit, a typical prerequisite of autophagy, which is indicated by a fall in mitochondrial potential, and the activity of mitochondrial complexes. On the contrary, spermine sustains energy metabolism by upregulating the activity of appropriate genes, including those that encode glyceraldehyde 3-phosphate dehydrogenase GAPDH and SNF1-related protein kinase 1 SnRK1. Taken together, our data suggest that one of the key roles for NO in plants may be to trigger autophagy via diverse mechanisms, thus facilitating the removal of oxidized and damaged cellular constituencies.

Iron-modified biochar improves plant physiology, soil nutritional status and mitigates Pb and Cd-hazard in wheat (Triticum aestivum L.).

Environmental quality and food safety is threatened by contamination of lead (Pb) and cadmium (Cd) heavy metals in agricultural soils. Therefore, it is necessary to develop effective techniques for remediation of such soils. In this study, we prepared iron-modified biochar (Fe-BC) which combines the unique characteristics of pristine biochar (BC) and iron. The current study investigated the effect of pristine and iron modified biochar (Fe-BC) on the nutritional values of soil and on the reduction of Pb and Cd toxicity in wheat plants (Triticum aestivum L.). The findings of present study exhibited that 2% Fe-BC treatments significantly increased the dry weights of roots, shoots, husk and grains by 148.2, 53.2, 64.2 and 148%, respectively compared to control plants. The 2% Fe-BC treatment also enhanced photosynthesis rate, transpiration rate, stomatal conductance, intercellular CO2, chlorophyll a and b contents, by 43.2, 88.4, 24.9, 32.5, 21.4, and 26.7%, respectively. Moreover, 2% Fe-BC treatment suppressed the oxidative stress in wheat plants by increasing superoxide dismutase (SOD) and catalase (CAT) by 62.4 and 69.2%, respectively. The results showed that 2% Fe-BC treatment significantly lowered Cd levels in wheat roots, shoots, husk, and grains by 23.7, 44.5, 33.2, and 76.3%. Whereas, Pb concentrations in wheat roots, shoots, husk, and grains decreased by 46.4, 49.4, 53.6, and 68.3%, respectively. Post-harvest soil analysis showed that soil treatment with 2% Fe-BC increased soil urease, CAT and acid phosphatase enzyme activities by 48.4, 74.4 and 117.3%, respectively. Similarly, 2% Fe-BC treatment significantly improved nutrients availability in the soil as the available N, P, K, and Fe contents increased by 22, 25, 7.3, and 13.3%, respectively. Fe-BC is a viable solution for the remediation of hazardous Cd and Pb contaminated soils, and improvement of soil fertility status.

Comparative stress response assessment of PFOS and its alternatives, F-53B and OBS, in wheat: An insight of toxic mechanisms and relative magnitudes

Emerging alternatives to perfluorooctane sulfonate (PFOS), including 6:2 chlorinated polyfluorinated ether sulfonate (F-53B) and p-perfluorous nonenoxybenzene sulfonate (OBS), have been widely detected in the real environment as PFOS restriction. However, the toxicity in plants and the underlying mechanism of F-53B and OBS remain scarce, especially compared to PFOS. PFOS and their emerging alternatives pose significant potential risks to food, especially for crops, safety and human health with the great convenience of high chemical stability. Germination toxicity, oxidative stress biomarkers, and metabolomics were used to compare the relative magnitudes of toxicity of PFOS and its alternatives in wheat (Triticum aestivum L.). PFOS, F-53B, and OBS inhibited wheat germination compared to the control group, with germination inhibition rates of 45.6%, 53.5%, and 64.3% at 400 μM PFOS, F-53B, and OBS exposure, respectively. Moreover, oxidative stress biomarker changes were observed in PFOS, F-53B, and OBS, with OBS being more pronounced. The chlorophyll concentrations in wheat shoots increased, and the anthocyanin concentration decreased along with the increased exposure concentration. Superoxide dismutase (SOD) activity increased in wheat root but decreased in the shoot. Peroxidase (POD) activity and malondialdehyde (MDA) concentration increased, whereas catalase (CAT) activity decreased. Regarding metabolomics, PFOS, F-53B, and OBS exposure (10 μM) significantly altered 85, 133, and 134 metabolites, respectively. According to KEGG enrichment analysis, F-53B specifically affects lipid metabolism, whereas OBS causes an imbalance in amino acid and carbohydrate metabolism. These findings suggested that PFOS, F-53B, and OBS have distinct toxic mechanisms. Thus, our results indicated that the relative size of the toxicity in wheat is as follows: OBS > F-53B > PFOS, and this finding provides a new reference basis for the phytotoxicity assessment of F-53B and OBS.

Enantioselective uptake, translocation, and biotransformation of pydiflumetofen in wheat (Triticum aestivum L.): Insights from chiral profiling and molecular simulation

Pydiflumetofen (PYD), a highly effective and broad-spectrum fungicide, is commonly employed for the control of fungal diseases. In this study, the uptake, translocation, and biotransformation of PYD by wheat (Triticum aestivum L.) were firstly investigated at a chiral level. The findings revealed that the residue concentration of R-PYD in wheat was higher than that of S-PYD, because of its higher uptake rate (k1 = 0.0421 h−1) and lower elimination rate (k2 = 0.0459 h−1). Additionally, R-PYD exhibited higher root bioconcentration factors and translocation factors compared with S-enantiomer, indicating R-PYD was more easily accumulating in roots and translocating to shoots. Furthermore, a total of 9 metabolites, including hydroxylated, demethylated, demethoxylated, dechlorinated, hydrolyzed, and glycosylated-conjugated products, were detected qualitatively in wheat roots or shoots. Symplastic pathway-mediated uptake, which predominantly relied on aquaporins and anion channels, was confirmed by root adsorption and inhibition experiments, without displaying any enantioselective effect. Molecular simulations demonstrated that R-PYD exhibited stronger binding affinity with TaLTP 1.1 with a lower grid score (−6.79 kcal/mol), whereas weaker interaction with the metabolic enzyme (CYP71C6v1) compared to the S-enantiomer. These findings highlight the significance of plant biomacromolecules in the enantioselective bioaccumulation and biotransformation processes. Importantly, a combination of experimental and theoretical evidence provide a comprehensive understanding of the fate of chiral pesticides in plants from an enantioselective perspective.

Analyzing the impacts of cadmium alone and in co-existence with polypropylene microplastics on wheat growth.

Heavy metals typically coexist with microplastics (MPs) in terrestrial ecosystems. Yet, little is known about how the co-existence of heavy metals and MPs affect crops. Therefore, this study aimed to evaluate the impact of cadmium (Cd; 40 mg/L) alone and its co-existence with polypropylene (PP)-MPs (50 and 100 µm) on seed germination, root and shoot growth, seedling dry weight (DW), and antioxidant enzyme activities of wheat. The study demonstrated that the germination rate of wheat did not vary significantly across treatment groups. Yet, the inhibitory impact on wheat seed germination was strengthened under the co-existence of Cd and PP-MPs, as the effect of a single treatment on seed germination was non-significant. The germination index and mean germination time of wheat seeds were not affected by single or combined toxicity of Cd and PP-MPs. In contrast, Cd and PP-MPs showed synergistic effects on germination energy. Wheat root and shoot length were impeded by Cd alone and in combination with PP-MPs treatments. The DW of wheat seedlings showed significant change across treatment groups until the third day, but on the seventh day, marginal differences were observed. For example, on third day, the DW of the Cd treatment group increased by 6.9% compared to CK, whereas the DW of the 100 µm PP-MPs+Cd treatment group decreased by 8.4% compared to CK. The co-occurrence of Cd and PP-MPs indicated that 50 μm PP-MPs+Cd had an antagonistic impact on wheat seedling growth, whereas 100 μm PP-MPs+Cd had a synergistic impact due to the larger size of PP-MPs. The antioxidant enzyme system of wheat seeds and seedlings increased under single Cd pollution, while the activities of superoxide dismutase, catalase, and peroxidase were decreased under combined pollution. Our study found that Cd adversely affects wheat germination and growth, while the co-existence of Cd and PP-MPs have antagonistic and synergistic effects depending on the size of the PP-MPs.

Durum wheat-lentil relay intercropping enhances soil mycorrhizal activity but does not alter structure of arbuscular mycorrhizal fungal community within roots

In intercropping systems, crop species select host-adapted microorganisms and influence the associated plant-microbial interactions like in the case of arbuscular mycorrhizal fungi (AMF). Attempts to assess the impact of intercropping on the activity, diversity, and community composition of AMF remain inconclusive, more so in intercropping systems involving traditional Mediterranean crops such as durum wheat and lentils. We carried out field experiments in Central Italy to assess the impact of relay intercropping durum wheat (Triticum durum Desf. cv. Minosse) and lentil (Lens culinaris Medik. cv. Elsa) on soil mycorrhizal inoculum potential (MIP) (2019 and 2020), AMF root colonization (2019, 2020, and 2021), and root AMF diversity and community composition (2020 and 2021), compared to the respective sole crops. Results showed that relay intercropping enhanced lentil grain yield and durum wheat grain protein concentration but marginally reduced durum wheat grain yield and lentil grain protein concentration. In addition, relay intercropping enhanced soil mycorrhizal activity but differentially influenced mycorrhizal root colonization compared to sole cropping. Sequencing analyses generated a total of 234 amplicon sequence variants belonging to Glomeromycota, which were assigned to 31 virtual taxa using the MaarjAM reference database. Glomeraceae and Claroideoglomeraceae were the most abundant taxa but had contrasting abundances in 2020 and 2021. The overall changes in AMF species diversity and community structure were affected by the interaction between crop species and year, and not by intercropping. Claroideoglomus and Septoglomus showed a strong association with lentil roots while Rhizophagus and Paraglomus were associated with durum wheat roots in 2020, affirming host genotype-AMF preferences. The principal component analysis showed that grain protein concentration was associated with selected mycorrhizal parameters such as community richness and AMF root colonization. Further studies on the functional analysis of the different AMF communities selected by the crop genotype and year may reveal the importance of intercropping in maintaining soil functionality and productivity under low-input systems.

Optimizing soil and fertilizer management strategy to facilitate sustainable development of wheat production in a semi-arid area: A 12-year in-situ study on the Loess Plateau

ContextThe low precipitation and low soil fertility in the Loess Plateau region of China limit the sustainable development of farmland. No-tillage, straw mulching, or planting green manure can improve soil water storage or soil quality. However, further research is needed to optimize these soil and fertilizer management strategies to maximize yield and effectively utilize resources. ObjectiveThe present study aimed to determine the optimal soil and fertilizer management strategies to maximize wheat growth and water/nitrogen utilization efficiency, while minimizing nitrogen fertilizer input. MethodsFive different soil and fertilizer treatments were tested on the Loess Plateau between 2009 and 2021, including traditional tillage followed by bare soil (CK), no-till with straw mulching (NTSM), no-till with straw mulching followed by leguminous green manure (OPT), and reductions in N fertilizer inputs of 10% (OPT10) and 20% (OPT20) under OPT. ResultsThe average results from 12 years of research revealed that the soil water content (SWC) and NO3–-N content in the 0–20 cm soil depth under OPT were higher by 4.3% and 13.4% compared to CK (P < 0.01), and the length and surface area of the wheat roots were higher by 20.9% and 11.0% (P < 0.01), respectively. Optimized soil and fertilizer management delayed leaf senescence and enhanced the antioxidant and photosynthetic capacities of the wheat crop. Compared with CK, the net photosynthetic rate and superoxide dismutase activity were 38.6% and 11.6% higher under OPT, respectively, and no significant differences were observed between OPT and OPT10. Optimized soil and fertilizer management promoted wheat yield formation, water and fertilizer use efficiency, and OPT obtained the highest yield (4497.3 kg ha−1), N uptake (138.7 kg ha−1), and water use efficiency (WUE, 13.3 kg ha−1). Compared with CK, OPT increased the wheat yield, N uptake, WUE, and WP by 21.5%, 16.7%, 16.6%, and 12.6%, respectively, and there were no significant differences between OPT10 and OPT. ConclusionsOptimizing the soil and fertilizer management strategies increased the soil water and NO3–-N contents, delayed leaf senescence, enhanced the leaf antioxidant and photosynthetic capacities, promoted wheat yield formation and efficient resource utilization. A 10% reduction in N fertilizer input based on no-till, straw mulching and green manure planting during the fallow period is an efficient soil and fertilizer management strategy for ensuring sustainable wheat production in semi-arid areas of the Loess Plateau. ImplicationsOur findings provide a reference for wheat production in semi-arid regions similar to the Loess Plateau throughout the world.

DNA-based assessment of root lesion nematode infections in cereal roots

Root lesion nematodes (RLN) of the genus Pratylenchus are causing significant damage in cereal production worldwide. Due to climate change and without efficient and environment-friendly treatments, the damages through RLNs are predicted to increase. Microscopic assessments of RLNs in the field and the greenhouses are time-consuming and laborious. As a result, cereal breeders have mostly ignored this pest. We present a method measuring RLN in infected cereal roots using a standardized PCR approach. Publicly available Pratylenchus neglectus primer combinations were evaluated. An optimal primer combination for RT-qPCR assay was identified to detect and quantify P. neglectus within infected cereal roots. Using the RT-qPCR detection assay, P. neglectus could be clearly distinguished from other plant parasitic nematodes. We could identify P. neglectus DNA in barley and wheat roots as low as 0.863 and 0.916 ng/µl of total DNA, respectively. A single P. neglectus individual was detected in water suspension and within barley and wheat roots. The RT-qPCR detection assay provides a robust and accurate alternative to microscopic nematode identification and quantification. It could be of interest for resistance breeding, where large populations must be screened to detect and quantify P. neglectus in farmer’s fields.

Prevalence and Importance of the Necrotrophic Effector Gene ToxA in Bipolaris sorokiniana Populations Collected from Spring Wheat and Barley.

Bipolaris sorokiniana is a necrotrophic fungal pathogen that causes foliar and root diseases on wheat and barley. These diseases are common in all wheat- and barley-growing regions, with more severe outbreaks occurring under warm and humid conditions. B. sorokiniana can also infect a wide range of grass species in the family Poaceae and secrete ToxA, an important necrotrophic effector also identified other wheat leaf spotting pathogens. In this study, the prevalence and virulence role of ToxA were investigated in a collection of 278 B. sorokiniana isolates collected from spring wheat and barley in the Upper Midwest of the United States or other places, including 169 from wheat leaves, 75 from wheat roots, 30 from barley leaves, and 4 from wild quack grass leaves. ToxA was present in the isolates from wheat leaves, wheat roots, and wild grass leaves but was absent from isolates collected from barley leaves. Prevalence of ToxA in wheat leaf isolates (34.3%) was much higher than that in wheat root isolates (16%). Sequencing analysis revealed the presence of two haplotypes, with the majority being BsH2. All ToxA+ isolates produced the functional effector in liquid cultures. Pathogenicity assays revealed that ToxA+ isolates caused significantly more disease on spring wheat lines harboring Tsn1 than their tsn1 mutants, suggesting that the ToxA-Tsn1 interaction plays an important role in spot blotch development. This work confirms the importance of ToxA in B. sorokiniana populations infecting wheat and, thus, the need to eliminate Tsn1 from spring wheat cultivars to reduce susceptibility to spot blotch.

Root growth and physiological responses in wheat to topsoil and subsoil compaction with or without artificial vertical macropores

The process of soil compaction can cause various stresses on roots, ultimately limiting their growth and development within the soil. Understanding this phenomenon in real-world conditions can be challenging since the growth of roots is influenced by the soil environment. To investigate this issue, four experiments were conducted to examine the impact of topsoil (two in pots: with clay loam and sandy loam soils under two soil water regimes) and subsoil (in rhizobox: one with clay loam soil and the other with sandy loam soil, containing artificial vertical macropores) compaction on the relationship between edaphic factors and the physiological response of wheat roots. The topsoil compaction reduced root length, volume, and weight by 30–50% and the root diameter by ∼15% compared to the non-compact soil. The effect was reduced in the soil with higher clay content (clay loam), especially under the limited soil water condition. Plant physiological responses were adversely affected by compaction with a reduction in plant height. The transpiration rate was highly impacted (21–47% reduction) with the build-up of intercellular CO2 content in leaves (13–31%), especially with limited water applications. Root growth was severely restricted (>60%) in the compact subsoil layer, although the surface area and volume of roots increased in the overlying non-compact layer. Naturally occurring or artificial vertical macropores acted as escape channels, facilitating the roots to pass through the compact subsoil and grow abundantly in the loose soil below. However, plants in field conditions encounter a mix of loose and compact soil zones. By studying how roots respond to this soil heterogeneity, we can develop strategies to reduce the negative effects of soil compaction.

Effects of arbuscular mycorrhizal fungi on zinc uptake, translocation and accumulation in winter wheat during whole plant growth stages

Although arbuscular mycorrhizal fungi (AMF) could play important roles in zinc (Zn) uptake in host plants, the effects of AMF on Zn uptake and transport in winter wheat during the whole growth stage remain unclear. A pot experiment was conducted to investigate the effects of Funneliformis mosseae (Fm) and Claroideoglomus etunicatum (Ce) on Zn absorption, transport, and accumulation in winter wheat under different Zn levels (0, 2.5, and 25 mg kg–1) in soils. This study showed that there was a significant correlation between mycorrhizal colonization rate and Zn absorption efficiency in winter wheat roots during the post-anthesis period, but there was no significant correlation during the pre-anthesis period. AMF significantly increased Zn concentrations (0.64–0.81 times) in wheat grains under 0 mg kg-1 Zn level, but decreased Zn concentrations in wheat grains under 25 mg kg-1 Zn level. Additionally, under 0 and 2.5 mg kg–1 Zn treatments, AMF increased Zn absorption rate (3.3–14, 0.21–1.02 times) in roots at filling and maturity stages and the contribution of root Zn uptake (0.36–0.64, 0.27–0.37 times) to grain Zn. However, AMF decreased root Zn absorption rate (0.32–0.61 times) and increased the contribution of Zn remobilization (1.69–2.01 times) in vegetative tissues to grain Zn under 25 mg kg–1 Zn treatment. The present results would complement the mechanisms and effects of AMF on Zn absorption and transport in winter wheat and provide a potential method for the application of AMF to wheat grain Zn enrichment.

LaCl3 Induces Genomic DNA Instability and Increases DNA Methylation Levels in Wheat Roots

LaCl3 Induces Genomic DNA Instability and Increases DNA Methylation Levels in Wheat Roots

Plant parasitic nematodes in the soil and roots of winter wheat grown in crop rotation and long-term monoculture

Plant parasitic nematodes in the soil and roots of winter wheat grown in crop rotation and long-term monoculture

Cerium oxide nanoparticles alleviates stress in wheat grown on Cd contaminated alkaline soil

The cadmium contamination of soil is an alarming issue worldwide and among various mitigation strategies, nanotechnology mediated management of Cd contamination has become a well-accepted approach. The Cerium Oxide Nanoparticles (CeO2-NPs) are widely being explored for their novel works in Agro-Industry and Environment, including stress mitigation in crops. Very little work is reported regarding role of CeO2-NPs in management of Cd contamination in cereal crops like wheat. Present work was planned to check efficacy of CeO2-NPs in Cd stress mitigation of wheat under alkaline calcareous soil conditions. In this experiment, 4 sets of Cd contamination (Uncontaminated control-UCC, 10, 20, and 30 mg Cd per kg soil) and 5 sets of CeO2-NPs NPs (0, 200, 400, 600, and 1000 mg NP per kg soil) were applied in pots following completely randomized design (CRD) and wheat crop was grown. The growth, physiology, yield and Cd and Ce accumulation by wheat root, shoot and grain was monitored. The maximum Cd spiking level (30 mg kg−1) was found to be most toxic for plant growth. The results showed that the nanoparticles were overall beneficial for wheat growth and maximum level (1000 mg kg−1) being the most significant one under all Cd spiking sets. In Cd-30 sets, 1000 mg kg−1 NPs application resulted in decreased soil bioavailable Cd concentration (49.63% decrease compared to 30 mg kg−1 Cd spiked sets termed as Cd-30 Control), decreased Cd accumulation in all three tissues: root (58.36% decrease), shoot (52.30% decrease) and grain (55.56% decrease) while increased root dry weight (62.14%), shoot dry weight (89.32%), total grain yield (80.08%) and improved plant physiology with respect to Cd-30 control. Nanoparticles application substantially increased wheat root, shoot and grain Ce concentrations as well. The further prospects of these nanoparticles in relation to various biotic and abiotic stresses are advised to be explored.

Purification effects show seed and root mucilage's ability to respond to changing rhizosphere conditions.

Mucilage, a polysaccharide-containing hydrogel, is hypothesized to play a key role in the rhizosphere as a self-organized system because it may vary its supramolecular structure with changes in the surrounding solution. However, there is currently limited research on how these changes are reflected in the physical properties of real mucilage. This study examines the role of solutes in maize root, wheat root, chia seed, and flax seed mucilage in relation to their physical properties. Two purification methods, dialysis and ethanol precipitation, were applied to determine the purification yield, cation content, pH, electrical conductivity, surface tension, viscosity, transverse 1 H relaxation time, and contact angle after drying of mucilage before and after purification. The two seed mucilage types contain more polar polymers that are connected to larger assemblies via multivalent cation crosslinks, resulting in a denser network. This is reflected in higher viscosity and water retention ability compared to root mucilage. Seed mucilage also contains fewer surfactants, making them better wettable after drying compared to the two root mucilage types. The root mucilage types, on the other hand, contain smaller polymers or polymer assemblies and become less wettable after drying. However, wettability not only depends on the amount of surfactants but also on their mobility, as well as the strength and mesh size of the network structure. The changes in physical properties and cation composition observed after ethanol precipitation and dialysis suggest that the polymer network of seed mucilage is more stable and specialized in protecting the seeds from unfavorable environmental conditions. In contrast, root mucilage is characterized by fewer cationic interactions and its network relies more on hydrophobic interactions. This allows root mucilage to be more flexible in responding to changing environmental conditions, facilitating nutrient and water exchange between root surfaces and the rhizosphere soil.

First Report of Fusarium nygamai Causing Crown Rot of Wheat in China.

Fusarium crown rot (FCR) is an important disease on wheat (Triticum aestivum L.) all over the world. Fusarium pseudograminearum is reported the main causal agent of FCR in China (Deng et al. 2020). In 2020, FCR occurred in wheat in Langfang, Hebei Province (116.31°E, 38.82°N) with observed incidence of 37.2% (48 out of 129 plants in total). The diseased wheat showed brown lesions at the crown and then stem necrosis. Samples with diseased symptom were collected from fields in late May 2020 (at the premature stage, 36 weeks after planting) (e-Xtra 1A). To perform fungal isolation, 0.3 cm2 samples excised at the symptomatic crown were surface disinfested with 75% ethanol for 10 s, and 0.1% HgCl2 for 40 s, then washed three times with sterile ddH2O. When cultured on potato dextrose agar (PDA), the colonies of two isolates out of Langfang (11.8% frequency) initially arewhite becoming violet with age, with violet pigments produced on PDA (e-Xtra 1B). Single-spored isolates were acquired, macroconidia were slender, thin walled, with 3- to 5-septate, measurements of 15.7-31.4 µm × 2.7-6.3 µm (n=50) (e-Xtra 1C). The pure culture were named as HWA94 and HWA97, respectively. DNA was extracted from the single-spored mycelium of HWA97 using the CTAB method (Leslie and Summerell, 2006). Internal transcribed spacer (ITS) region, partial sequences of actin (ACT), translation elongation factor 1-α (EF-1α) gene, 28S ribosomal RNA (LSU), and DNA-dependent RNA polymerase II largest subunit rpb1 (RPB1) were amplified using primers ITS1/ITS4, EF-1F/EF-1R, ACT512F/ACT728R, LR/LROR and RPB1B-F/ RPB1B-R and sequenced. The ITS, EF-1α, ACT, LSU, and RPB1 sequences were deposited in GenBank under accession numbers OM459813 to OM459817. These sequences showed 99.64%, 100%, 100%, 100%, and 100% similarity with the reference strain F. nygamai CBS749.97, respectively, resulting in HWA97 being identified as F. nygamai. To confirm the pathogenicity, inoculum was prepared by inoculating fully colonized F. nygamai (HWA97) PDA plugs on sterile wheat grain medium, cultured 7 days at 25℃ till massive mycelium formed, and hand shaken every two days to mix the wheat grains and the F. nygamai mycelium completely. Ten wheat seeds (cv. Jimai22, susceptible to FCR) for each 10-cm pot were inoculated with 10 g of inoculum when planting, then covered with soil. Mock inoculated wheat seeds with sterile grain without inoculum were used as control. The experiment was conducted in greenhouse, and repeated three times. Symptoms (brown necrosis at the crown) appeared 35 days after inoculation (dai) (e-Xtra 1D), with 91.5% incidence and 49.5±2.6 disease index. Mock-inoculated plants remained symptomless (e-Xtra 1E). Fusarium nygamai was re-isolated from the symptomatic stem and identified by morphological and molecular analysis, fulfilling Koch's postulates. Fusarium nygamai has been previously reported and recovered from wheat root and stalk (Fard et al. 2017) and causes root rot on wheat in Iraq (Minati, 2020), rice in Sardinia (Balmas et al. 2000), sugar beet in China (Cao et al. 2018), as well as lentil (Lens culinaris Medikus) in Pakistan (Rauf et al. 2016). To our knowledge, this is the first report of F. nygamai causing FCR of wheat in China. This study contributes useful information for epidemiologic studies for FCR. Additional studies will be needed to determine the distribution, aggressiveness, and impact on yield of F. nygamai compared with the dominant causal agent F. pseudograminearum.

Changes in the Amount and Distribution of Soil Nutrients and Neighbours Have Differential Impacts on Root and Shoot Architecture in Wheat (Triticum aestivum).

Plants exhibit differential behaviours through changes in biomass development and distribution in response to environmental cues, which may impact crops uniquely. We conducted a mesocosm experiment in pots to determine the root and shoot behavioural responses of wheat, T. aestivum. Plants were grown in homogeneous or heterogeneous and heavily or lightly fertilized soil, and alone or with a neighbour of the same or different genetic identity (cultivars: CDC Titanium, Carberry, Glenn, Go Early, and Lillian). Contrary to predictions, wheat did not alter relative reproductive effort in the presence of neighbours, more nutrients, or homogenous soil. Above and below ground, the plants' tendency to use potentially shared space exhibited high levels of plasticity. Above ground, they generally avoided shared, central aerial space when grown with neighbours. Unexpectedly, nutrient amount and distribution also impacted shoots; plants that grew in fertile or homogenous environments increased shared space use. Below ground, plants grown with related neighbours indicated no difference in neighbour avoidance. Those in homogenous soil produced relatively even roots, and plants in heterogeneous treatments produced more roots in nutrient patches. Additionally, less fertile soil resulted in pot-level decreases in root foraging precision. Our findings illustrate that explicit coordination between above- and belowground biomass in wheat may not exist.

Insights concerning advancing the agroecological sustainability of salinity tolerance through proteomics profiling of hexaploid wheat (Triticum aestivum L.)

Wheat plays a significant role in the provision of food and nutrition. However, rapid soil salinization poses a severe threat to its production worldwide. Salt stress stunts wheat growth and quality, resulting in low grain yields. The adaptation of wheat to salinity involves complex physio-biochemical and molecular mechanisms. This study aimed to identify the genetic approaches concerning salt stress-responsive proteins and protein pathways in wheat roots under controlled (0 mM) and NaCl stress (250 mM) solution using label-free proteomic quantification analysis. We found a significant accumulation of Na+ in the leaf and root compared with the controlled condition. Besides, we identified 2436 proteins enhanced under salt stress, with 198 differentially abundant proteins (DAPs), including 170 up-regulated and 28 down-regulated proteins. Many of these proteins were involved in salinity tolerance, including heat shock proteins, glutathione S-transferase, dehydrin, peroxidase, potassium channel beta subunit-type H+-ATPase, superoxide dismutase (Cu-Zn), 14-3-3 protein, peroxidase, malate dehydrogenase, and heat shock proteins. The abundance of a V-type H+ ATPase and 14-3-3 protein was also enhanced, facilitating Na+ compartmentalization in the vacuole through the salt overly sensitive (SOS) pathway. Additionally, many antioxidant enzymes, including peroxidase, glutathione-S-transferase, and thioredoxins, were up-regulated, playing a vital role in detoxifying reactive oxygen species (ROS) in salinity-stressed wheat roots. Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) enrichment analyses showed that salinity stress enhances the abundance of proteins in several metabolic pathways, such as the citrate cycle, ribosome, oxidative phosphorylation, glycolysis, carbon metabolism, and cytoplasm. We anticipate that the identified proteins under salinity conditions will provide us with a deeper understanding of their application in agriculture biotechnology.

High-Quality Nuclear Genome and Mitogenome of Bipolaris sorokiniana LK93, a Devastating Pathogen Causing Wheat Root Rot.

Bipolaris sorokiniana, one of the most devastating hemibiotrophic fungal pathogens, causes root rot, crown rot, leaf blotching, and black embryos of gramineous crops worldwide, posing a serious threat to global food security. However, the host-pathogen interaction mechanism between B. sorokiniana and wheat remains poorly understood. To facilitate related studies, we sequenced and assembled the genome of B. sorokiniana LK93. Nanopore long reads and next generation sequencing short reads were applied in the genome assembly, and the final 36.4-Mb genome assembly contains 16 contigs with the contig N50 of 2.3 Mb. Subsequently, we annotated 11,811 protein-coding genes. Of these, 10,620 were functional genes, 258 of which were identified as secretory proteins, including 211 predicted effectors. Additionally, the 111,581-bp mitogenome of LK93 was assembled and annotated. The LK93 genomes presented in this study will facilitate research in the B. sorokiniana-wheat pathosystem for better control of crop diseases. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Drip fertilization improve water and nitrogen use efficiency by optimizing root and shoot traits of winter wheat.

Proper irrigation and fertilization measures can not only improve water and fertilizer utilization efficiency, but also have important significance in ensuring agricultural environment security and sustainable development. A field experiment was conducted to determine the optimal drip fertilization measure of winter wheat and explain its mechanism by analyzing the physiological and ecological characteristics and utilization efficiency of water and nitrogen under different irrigation and fertilization methods. The plants were treated with three irrigation and fertilization methods: the traditional irrigation and fertilization method (CK), surface drip fertilization (I1) and underground drip fertilization (I2). The results demonstrated that different irrigation methods had various effects on population and physiological characteristics of wheat. The plant height, leaf area and tiller number of I1 were significantly higher than those of CK during the whole growth period. I2 decreased plant height, leaf area and tiller number at jointing stage, but at flowering stage, the leaf area of I2 t was significantly higher than that of CK. Different irrigation methods also affected the root distribution of wheat. At flowering stage, I1 had lower root biomass than CK in all soil layers. The upper root system of I2 was smaller, but the deep root system was larger compared with the control. I1 and I2 had lower total root weight and higher shoot biomass compared to CK, so their root-shoot ratio decreased significantly. I1 and I2 increased and instantaneous water use efficiency (IWUE) by increasing the photosynthetic rate (Pn) and reducing transpiration rate (Tr) at the flowering stage, while I2 had a similar Pn to I1, but reduced Tr, resulting in a higher IWUE than I1. Both I1 and I2 also increased root efficiency, root activity, and Fv/Fm of wheat at the late growth stage, promoting accumulated dry matter after flowering (ADM) and pre-flowering dry matter remobilization (DMR), leading to a significant increase in grain yield. In addition, I1 and I2 had significantly higher water productivity (WP), irrigation water productivity (IWP), nitrogen partial productivity (NPP) and nitrogen agronomic efficiency (NAE) than CK, especially I2 had the highest IWP, WP, NPP and NAE. These findings highlight the potential benefits of drip fertilization in promoting sustainable wheat production and elucidate the mechanism by which it promotes efficient use of water and fertilizer.