Fungal endophytes improve wheat seed germination under heat and drought stress

Botany ◽  
2012 ◽  
Vol 90 (2) ◽  
pp. 137-149 ◽  
Author(s):  
Michelle Hubbard ◽  
James Germida ◽  
Vladimir Vujanovic
Keyword(s):  
Drought Stress ◽  
Seed Germination ◽  
Life Stage ◽  
Fungal Endophytes ◽  
Fungal Endophyte ◽  
Wheat Seed ◽  
Hydrothermal Time ◽  
Fresh Weight ◽  
First Time ◽  
Stressful Environments

Seed germination is a critical life stage for plants survival and timely seedling establishment especially in stressful environments. We hypothesized that fungal endophytes would improve wheat seed germination under heat and drought stress. The hydrothermal time (HTT) model of germination is a conceptual model useful for predicting the timing and energy of germination (EG) under a given set of conditions. The HTT and EG are applied, for the first time, to determine if one or more compatible endophytic fungi enhance heat or drought tolerance in wheat. Fungal endophytes tested dramatically increased the percent of germination, improved EG and HTT values, and diminished wheat susceptibility to heat and drought as measured by fresh weight of seedlings. When colonized by the most effective fungal endophyte, the values of the parameters tested in wheat seeds exposed to heat stress resembled those of unstressed seeds.

scholarly journals Interaction between plant genotype and the symbiosis with Epichloë fungal endophytes in seeds of red fescue (Festuca rubra)

2011 ◽  
Vol 62 (11) ◽  
pp. 1010 ◽  
Author(s):  
P. E. Gundel ◽  
I. Zabalgogeazcoa ◽  
B. R. Vázquez de Aldana
Keyword(s):  
Seed Germination ◽  
Fungal Endophytes ◽  
Germination Percentage ◽  
Fungal Endophyte ◽  
Festuca Rubra ◽  
Plant Genotype ◽  
Host Genotype ◽  
Natural Habitats ◽  
Incubation Condition ◽  
Seed Survival

In diverse natural habitats of Europe, plants of Festuca rubra are commonly infected by the fungal endophyte Epichloë festucae. Under several circumstances, the association between the grass and the fungus has been shown to be mutualistic. Here, we conducted an experiment to study the differences in seed germination and mortality between infected (E+) and endophyte-free plants (E–) at different temperatures (12 and 25°C) and water potentials (0 and –0.5 MPa). Three half-sib lines of F. rubra, each composed of E+ and E– seeds, and derived from infected plants from semiarid grasslands were used. Although the endophyte effect depended on the incubation condition, germination percentage was significantly greater for E– (52%) than for E+ seeds (41%). Seed germination was more inhibited by the low water potential (75 v. 24% for –0.5 and 0.0 MPa, respectively), than by the high temperature (64 v. 35% for 25 and 12°C, respectively). However, mortality was highly dependent on the interaction between plant genotype and endophyte, and between temperature and water condition. It is remarkable that while highly dependent on the host genotype, there was a clear effect of endophyte increasing seed survival, especially in those treatments that were unfavourable for germination. For example, in the more restrictive treatment (25°C and –0.5 MPa), seed survival was on average, 44 and 39% for E+ and E–, respectively. In general, the endophyte affected seed characteristics of F. rubra by reducing the percentage of germination, but simultaneously increasing seed survival.

scholarly journals Ameliorative effects of TiO2 nanoparticles and sodium nitroprusside on seed germination and seedling growth of wheat under PEG-stimulated drought stress

2019 ◽  
Vol 41 (3) ◽  
pp. 309-317 ◽  
Author(s):  
Javad Faraji ◽  
Ali Sepehri
Keyword(s):  
Drought Stress ◽  
Seed Germination ◽  
Sodium Nitroprusside ◽  
Tio2 Nanoparticles ◽  
Seedling Growth ◽  
Severe Drought ◽  
Fresh Weight ◽  
Tio2 Nps ◽  
Early Seedling Growth ◽  
Early Seedling

Abstract: Seed germination and early seedling growth are sensitive to drought stress in wheat. A factorial experiment was arranged based on a completely randomized design with three replicates to study the impacts of TiO2 nanoparticles (TiO2 NPs: 0, 500, 1000 and 2000 mg.L) and sodium nitroprusside (SNP: 0 and 100 μM), as NO donor, on seed germination and seedling growth of wheat under polyethylene glycol (PEG)-induced drought stress (0, -0.4 and -0.8 MPa). Our results revealed that PEG-stimulated drought stress significantly decreased germination percentage (GP), germination energy (GE), germination rate (GR), root length (RL), shoot length (SL), root fresh weight (RFW), shoot fresh weight (SFW) and vigor index (VI) but increased mean germination time (MGT) in wheat seeds. However, application of TiO2 NPs and SNP alone or in combination significantly enhanced GP, GE, GR, RL, SL, RFW, SFW and VI up to 23.72%, 50%, 33.74%, 85.38%, 93.28%, 73%, 91.91% and 91.04% respectively, but significantly reduced MGT up to 28.36% under severe drought stress. Our results showed that application of TiO2 NPs and SNP alone or in combination can significantly alleviate the adverse effects of PEG-stimulated drought stress on seed germination and early seedling growth of wheat.

Does N deposition mitigate the adverse impacts of drought stress on plant seed germination and seedling growth?

2020 ◽  
Vol 109 ◽  
pp. 103650
Author(s):  
Shu Wang ◽  
Mei Wei ◽  
Bingde Wu ◽  
Huiyuan Cheng ◽  
Kun Jiang ◽  
...  
Keyword(s):  
Drought Stress ◽  
Seed Germination ◽  
Seedling Growth ◽  
N Deposition ◽  
Plant Seed ◽  
Adverse Impacts

Penconazole and calcium ameliorate drought stress in canola by upregulating the antioxidative enzymes

2020 ◽  
Vol 47 (9) ◽  
pp. 825 ◽  
Author(s):  
Maryam Rezayian ◽  
Vahid Niknam ◽  
Hassan Ebrahimzadeh
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Drought Stress ◽  
Drought Tolerance ◽  
Antioxidative Enzymes ◽  
Proline Content ◽  
Fresh Weight ◽  
Negative Effects ◽  
Mda Content ◽  
Effects Of Drought

The aim of this research was to gauge the alternations in the lipid peroxidation and antioxidative enzyme activity in two cultivars (cv. RGS003 and cv. Sarigol) of canola under drought stress and drought tolerance amelioration by penconazole (PEN) and calcium (Ca). Plants were treated with different polyethylene glycol (PEG) concentrations (0, 5, 10 and 15%) without or with PEN (15 mg L–1) and Ca (15 mM). The Ca treatment prevented the negative effects of drought on fresh weight (FW) in RGS003 and Sarigol at 5 and 15% PEG respectively. Ca and PEN/Ca treatments caused significant induction in the proline content in Sarigol at 15% PEG; the latter treatment was accompanied by higher glycine betaine (GB), lower malondialdehyde (MDA) and growth recovery. Hydrogen peroxide (HO2) content in Sarigol was proportional to the severity of drought stress and all PEN, Ca and PEN/Ca treatments significantly reduced the H2O2 content. PEN and PEN/Ca caused alleviation of the drought-induced oxidative stress in RGS003. RGS003 cultivar exhibited significantly higher antioxidative enzymes activity at most levels of drought, which could lead to its drought tolerance and lower MDA content. In contrast to that of Sarigol, the activity of catalase and superoxide dismutase (SOD) increased with Ca and PEN/Ca treatments in RGS003 under low stress. The application of PEN and Ca induced significantly P5CS and SOD expression in RGS003 under drought stress after 24 h. Overall, these data demonstrated that PEN and Ca have the ability to enhance the tolerance against the drought stress in canola plants.

scholarly journals Tree Diversity Reduces Fungal Endophyte Richness and Diversity in a Large-Scale Temperate Forest Experiment

Diversity ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 234 ◽  
Author(s):  
Eric A. Griffin ◽  
Joshua G. Harrison ◽  
Melissa K. McCormick ◽  
Karin T. Burghardt ◽  
John D. Parker
Keyword(s):  
Phylogenetic Diversity ◽  
Large Scale ◽  
High Throughput Sequencing ◽  
Spatial Scales ◽  
Fungal Endophytes ◽  
Fungal Endophyte ◽  
Tree Diversity ◽  
Trophic Levels ◽  
Community Diversity ◽  
And Function

Although decades of research have typically demonstrated a positive correlation between biodiversity of primary producers and associated trophic levels, the ecological drivers of this association are poorly understood. Recent evidence suggests that the plant microbiome, or the fungi and bacteria found on and inside plant hosts, may be cryptic yet important drivers of important processes, including primary production and trophic interactions. Here, using high-throughput sequencing, we characterized foliar fungal community diversity, composition, and function from 15 broadleaved tree species (N = 545) in a recently established, large-scale temperate tree diversity experiment using over 17,000 seedlings. Specifically, we tested whether increases in tree richness and phylogenetic diversity would increase fungal endophyte diversity (the “Diversity Begets Diversity” hypothesis), as well as alter community composition (the “Tree Diversity–Endophyte Community” hypothesis) and function (the “Tree Diversity–Endophyte Function” hypothesis) at different spatial scales. We demonstrated that increasing tree richness and phylogenetic diversity decreased fungal species and functional guild richness and diversity, including pathogens, saprotrophs, and parasites, within the first three years of a forest diversity experiment. These patterns were consistent at the neighborhood and tree plot scale. Our results suggest that fungal endophytes, unlike other trophic levels (e.g., herbivores as well as epiphytic bacteria), respond negatively to increasing plant diversity.

scholarly journals Foliar applications of bio-fabricated selenium nanoparticles to improve the growth of wheat plants under drought stress

2020 ◽  
Vol 9 (1) ◽  
pp. 706-714
Author(s):  
Muhammad Ikram ◽  
Naveed Iqbal Raja ◽  
Bilal Javed ◽  
Zia-ur-Rehman Mashwani ◽  
Mubashir Hussain ◽  
...  
Keyword(s):  
Drought Stress ◽  
Field Capacity ◽  
Dry Weight ◽  
Positive Control ◽  
Morphological Characterization ◽  
Leaf Length ◽  
Selenium Nanoparticles ◽  
Fresh Weight ◽  
Wheat Varieties ◽  
Shoot Dry Weight

AbstractThe present study was aimed to biosynthesize selenium nanoparticles (SeNPs) and assess their foliar applications to improve the growth of wheat plants under controlled irrigation and drought stress. Bud aqueous extract of Allium sativum L. was used as a reducing and stabilizing agent of SeNPs followed by their optical and morphological characterization by using ultraviolet-visible spectroscopy, scanning electron microscopy, Fourier-transform infrared, and energy dispersive X-ray analysis. Various concentrations of SeNPs (10, 20, 30, and 40 mg/L) were applied exogenously to drought-tolerant (V1) and drought-susceptible (V2) wheat varieties at the trifoliate stage. Under the positive control conditions, plants were irrigated with 450 mL of water/pot (100% field capacity); and under water-deficit environment, plants were irrigated with 160 mL of water/pot (35% field capacity). Remarkable increase in plant height, shoot length, shoot fresh weight, shoot dry weight, root length, root fresh weight, root dry weight, leaf area, leaf number, and leaf length has been observed when 30 mg/L concentration of SeNPs was used. However, the plant morphological parameters decreased gradually at higher concentrations (40 mg/L) in both selected wheat varieties. Therefore, 30 mg/L concentration of SeNPs was found most preferable to enhance the growth of selected wheat varieties under normal and water-deficient conditions.

A light and electron microscope study of the fungal endophytes in the sporophyte and gametophyte of Lycopodium cernuum with observations on the gametophyte–sporophyte junction

1992 ◽  
Vol 70 (1) ◽  
pp. 58-72 ◽  
Author(s):  
Jeffrey G. Duckett ◽  
Roberto Ligrone
Keyword(s):  
Root Nodules ◽  
Fungal Endophytes ◽  
Fungal Endophyte ◽  
Peninsular Malaysia ◽  
Epidermal Cells ◽  
Host Cells ◽  
Wall Material ◽  
Intercellular Spaces ◽  
Host Cytoplasm ◽  
Fungal Associations

The ventral epidermal cells of the photosynthetic, surface-living gametophytes of Lycopodium cernuum, collected from moist shaded banks in Peninsular Malaysia, contain an aseptate fungus. In some cells the hyphae are thick walled and form coils encapsulated by a thin layer of host wall material. In others the fungus is thin walled and shows limited differentiation into larger trunk hyphae and arbuscules. The adjacent host cytoplasm, separated from the fungus by a granular interfacial matrix, contains numerous chloroplasts, mitochondria, and microtubules. The hyphae contact the substratum via the ventral walls of the epidermal cells and the rhizoids are free from infection. In the protocorm and root nodules, aseptate hyphae initially colonize mucilage-filled schizogenous intercellular spaces. Subsequent invasion of the host cells is associated with the development of massive overgrowths of host wall material. The fungal associations in L. cernuum share a mixture of attributes otherwise found in different angiosperm mycorrhizae and in mycotrophic relationships in liverworts. Wall ingrowths are present in both the gametophyte and sporophyte cells in the placenta of L. cernuum. The very limited development of the placenta, compared with L. appressum, certain bryophytes and ferns, the diminutive size, and early senescence of the gametophytes of L. cernuum are all linked to the presence of the protocorm. This massive absorptive organ, homologous to a foot, in terms of its position in sporophyte ontogeny, but external to the parent gametophyte, derives its nutrition partly from photosynthesis and partly from its fungal endophyte. Key words: chloroplasts, Lycopodium, mycorrhiza, pteridophytes, root nodules, symbiosis, transfer cells.

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