Silicon dioxide nanoparticles alleviate the threats of broomrape infection in tomato by inducing cell wall fortification and modulating ROS homeostasis

2020 ◽  
Vol 7 (5) ◽  
pp. 1415-1430
Author(s):  
Mahmoud M. Y. Madany ◽  
Ahmed M. Saleh ◽  
Talaat H. Habeeb ◽  
Wael N. Hozzein ◽  
Hamada AbdElgawad

An infographic diagram that summarizes the influence of SiNP-seed priming upon tomato plants under Orobanche infection conditions. GRW: growth, PHO: photosynthesis, NEAO: non-enzymatic antioxidants, ASE: antioxidant-scavenging enzymes.

2021 ◽  
Author(s):  
Blanca Salazar-Sarasua ◽  
María Jesús López-Martín ◽  
Edelín Roque ◽  
Rim Hamza ◽  
Luis Antonio Cañas ◽  
...  

ABSTRACTThe tapetum is a specialized layer of cells within the anther adjacent to the sporogenic tissue. During its short life, it provides nutrients, molecules and materials to the pollen mother cells and microsporocytes being essential during callose degradation and pollen wall formation. However, the acquisition of tapetal cell identity in tomato plants is a process still poorly understood. We report here the identification and characterization of SlTPD1 (Solanum lycopersicum TPD1), a gene specifically required for pollen development in tomato plants. Gene editing was used to generate loss-of-function Sltpd1 mutants that showed absence of tapetal tissue. In these plants, sporogenous cells developed but failed to complete meiosis resulting in complete male sterility. Transcriptomic analysis conducted in wild-type and mutant anthers at an early stage revealed the down regulation of a set of genes related to redox homeostasis. Indeed, Sltpd1 anthers showed a reduction of reactive oxygen species (ROS) accumulation at early stages and altered activity of ROS scavenging enzymes. The obtained results highlight the importance of ROS homeostasis in the interaction between the tapetum and the sporogenous tissue in tomato plants.One sentence summaryThe small protein SlTPD1 is required for tapetum formation in tomato, highlighting the role of this tissue in the regulation of redox homeostasis during male gametogenesis.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Jun Diao ◽  
Yinyin Xia ◽  
Xuejun Jiang ◽  
Jingfu Qiu ◽  
Shuqun Cheng ◽  
...  

Abstract Background Silicon dioxide nanoparticles (SiO2NPs) are widely used as additive in the food industry with controversial health risk. Gut microbiota is a new and hot topic in the field of nanotoxicity. It also contributes a novel and insightful view to understand the potential health risk of food-grade SiO2NPs in children, who are susceptible to the toxic effects of nanoparticles. Methods In current study, the young mice were orally administrated with vehicle or SiO2NPs solution for 28 days. The effects of SiO2NPs on the gut microbiota were detected by 16S ribosomal RNA (rRNA) gene sequencing, and the neurobehavioral functions were evaluated by open field test and Morris water maze. The level of inflammation, tissue integrity of gut and the classical indicators involved in gut–brain, gut–liver and gut–lung axis were all assessed. Results Our results demonstrated that SiO2NPs significantly caused the spatial learning and memory impairments and locomotor inhibition. Although SiO2NPs did not trigger evident intestinal or neuronal inflammation, they remarkably damaged the tissue integrity. The microbial diversity within the gut was unexpectedly enhanced in SiO2NPs-treated mice, mainly manifested by the increased abundances of Firmicutes and Patescibacteria. Intriguingly, we demonstrated for the first time that the neurobehavioral impairments and brain damages induced by SiO2NPs might be distinctively associated with the disruption of gut–brain axis by specific chemical substances originated from gut, such as Vipr1 and Sstr2. Unapparent changes in liver or lung tissues further suggested the absence of gut–liver axis or gut–lung axis regulation upon oral SiO2NPs exposure. Conclusion This study provides a novel idea that the SiO2NPs induced neurotoxic effects may occur through distinctive gut–brain axis, showing no significant impact on either gut–lung axis or gut–liver axis. These findings raise the exciting prospect that maintenance and coordination of gastrointestinal functions may be critical for protection against the neurotoxicity of infant foodborne SiO2NPs.


Toxics ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 51
Author(s):  
Jorge Humberto Limón-Pacheco ◽  
Natalie Jiménez-Barrios ◽  
Alejandro Déciga-Alcaraz ◽  
Adriana Martínez-Cuazitl ◽  
Mónica Maribel Mata-Miranda ◽  
...  

Some studies have shown that silicon dioxide nanoparticles (SiO2-NPs) can reach different regions of the brain and cause toxicity; however, the consequences of SiO2-NPs exposure on the diverse brain cell lineages is limited. We aimed to investigate the neurotoxic effects of SiO2-NP (0–100 µg/mL) on rat astrocyte-rich cultures or neuron-rich cultures using scanning electron microscopy, Attenuated Total Reflection-Fourier Transform Infrared spectroscopy (ATR-FTIR), FTIR microspectroscopy mapping (IQ mapping), and cell viability tests. SiO2-NPs were amorphous particles and aggregated in saline and culture media. Both astrocytes and neurons treated with SiO2-NPs showed alterations in cell morphology and changes in the IR spectral regions corresponding to nucleic acids, proteins, and lipids. The analysis by the second derivative revealed a significant decrease in the signal of the amide I (α-helix, parallel β-strand, and random coil) at the concentration of 10 µg/mL in astrocytes but not in neurons. IQ mapping confirmed changes in nucleic acids, proteins, and lipids in astrocytes; cell death was higher in astrocytes than in neurons (10–100 µg/mL). We conclude that astrocytes were more vulnerable than neurons to SiO2-NPs toxicity. Therefore, the evaluation of human exposure to SiO2-NPs and possible neurotoxic effects must be followed up.


2008 ◽  
Vol 133 (2) ◽  
pp. 300-311 ◽  
Author(s):  
Yu Sung ◽  
Daniel J. Cantliffe ◽  
Russell T. Nagata ◽  
Warley M. Nascimento

To investigate thermotolerance in seeds of lettuce (Lactuca sativa L.), primed, nonprimed, or seeds matured at 20/10 and 30/20 °C (day/night on a 12-h photoperiod) were imbibed at 36 °C for various periods and then dissected. Structural changes in seed coverings in front of the radicle tip were observed during germination at high temperature. Thermotolerant genotypes, ‘Everglades’ and PI 251245, were compared with a thermosensitive cultivar, ‘Dark Green Boston’. In all seeds that germinated, regardless of seed maturation temperature or priming, a crack appeared on one side of the cap tissue (constriction of the endosperm membrane near the basal end of the seed) at the micropylar region and the endosperm separated from the integument in front of the radicle tip. Additional changes took place during imbibition in these seeds; the protein bodies in the vacuoles enlarged and gradually depleted, large empty vacuoles formed, the cytoplasm condensed, the endosperm shrank, the endosperm cell wall dissolved and ruptured, and then the radicle elongated toward this ruptured area. The findings suggested that the endosperm layer presented mechanical resistance to germination in seeds that could not germinate at 36 °C. Weakening of this layer was a prerequisite to radicle protrusion at high temperature. Seeds of ‘Dark Green Boston’, ‘Everglades’, and PI 251245 matured at 30/20 °C had greater thermotolerance than those matured at 20/10 °C. Results of the anatomical study indicated that the endosperm cell walls in front of the radicle of seeds matured at 30/20 °C were more readily disrupted and ruptured during imbibition than seeds matured at 20/10 °C, suggesting a reason why these seeds could germinate quickly at supraoptimal temperatures. Similar endosperm structural alterations also were observed in primed seeds. Priming led to rapid and uniform germination, circumventing the inhibitory effects of high temperatures. From anatomical studies conducted to identify and characterize thermotolerance in lettuce seed germination, we observed that genotype, seed maturation temperature, or seed priming had the ability to reduce physical resistance of the endosperm by weakening the cell wall and by depleting stored reserves leading to cell collapse.


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