scholarly journals Changes in Mannitol Content, Regulation of Genes Involved in Mannitol Metabolism, and the Protective Effect of Mannitol onVolvariella volvaceaat Low Temperature

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Xu Zhao ◽  
Changxia Yu ◽  
Yan Zhao ◽  
Shunjie Liu ◽  
Hong Wang ◽  
...  

The mechanism of autolysis ofVolvariella volvacea(V. volvacea) at low temperature has not been fully explained. As mannitol is among the most important osmotic adjustment substances in fungal resistance, this study sampled mycelia of strains V23 and VH3 treated at 0°C for 0, 2, 4, 8, and 10 h to analyze changes in intracellular mannitol content by high-performance anion chromatography with pulsed amperometric detection (HAPEC-PAD). Reverse transcription quantitative PCR (RT-qPCR) analysis was applied to assess differences in the transcript levels of genes associated with mannitol metabolism under low-temperature stress. A mannitol solution was added to cultures ofV. volvaceafruiting bodies, and effects on the hypothermic resistance of these organs were explored by evaluating variations in sensory properties during cryogenic storage after harvest. The results suggested that in the initial stage of low-temperature treatment, intracellular mannitol was largely catabolized as an energy storage material and the expression of genes encoding enzymes involved in synthetic reactions was inhibited. However, low-temperature resistance was induced with further treatment, with activation of mannitol synthesis and inhibition of degradation; the cells accumulated mannitol, leading to osmoregulation. No significant elongation ofV. volvaceafruiting bodies during storage at 4°C was observed, and these organs tended to shrink and collapse. The sensory quality of mannitol-treated fruiting bodies was much better than that of control fruiting bodies. Application of a mannitol solution at the cultivation stage ofV. volvaceasomewhat improved the low-temperature resistance of the fruiting bodies, verifying the correlation between mannitol and resistance to this stress inV. volvacea. The results of this study lay a foundation for a deeper understanding of the autolysis mechanism ofV. volvacea, providing technical support for increasing the cryopreservation time of this species and extending the postharvest shelf life of its fruiting bodies. In addition, the mechanism underlying the low-temperature tolerance of the VH3 strain should be further explained at the molecular level.

Author(s):  
Jing Lu ◽  
Jianfeng Gu ◽  
Oudong Hu ◽  
Yunhan Fu ◽  
Dezhan Ye ◽  
...  

The conductive hydrogels have found large application prospects in fabricating flexible multifunctional electronic devices for future-generation wearable human-machine interactions. However, the inferior mechanical strength, low temperature resistance, and non-recyclability induced...


2021 ◽  
Author(s):  
Aiju Meng ◽  
Daxing Wen ◽  
Chunqing Zhang

Spring maize is usually subjected to low-temperature stress during seed germination, which retards seedling growth even if under a suitable temperature. However, the mechanism underlying maize seed germination under low-temperature stress modulating seedling growth after being transferred to normal temperature is still ambiguous. In this study, we used two maize inbred lines with different low-temperature resistance (SM and RM) to investigate the mechanism. The results showed that the SM line had higher lipid peroxidation and lower total antioxidant capacity and germination percentage than the RM line under low-temperature stress, which indicated that the SM line was more vulnerable to low-temperature stress. Further transcriptome analysis revealed that seed germination under low-temperature stress caused down-regulation of photosynthesis related gene ontology (GO) terms in two lines. Moreover, the SM line displayed down-regulation of ribosome and superoxide dismutase (SOD) related genes, whereas genes involved in SOD and vitamin B6 were up-regulated in the RM line. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that photosynthesis and antioxidant metabolism related pathways played important roles in seed germination in response to low-temperature stress, and the photosynthetic system displayed a higher damage degree in the SM line. Both qRT-PCR and physiological characteristics experiments showed similar results with transcriptome data. Taken together, we propose a model for maize seed germination in response to low-temperature stress.


Author(s):  
Zhurinov M.Zh., ◽  
◽  
Teltayev B.B., ◽  
Kalybay A.A., ◽  
Rossi C.O., ◽  
...  

A comparative analysis of the low temperature resistance for a nanocarbon bitumen and other 30 neat and modified bitumens has been performed in the work. The stiffness at the temperatures of -24°С, -30°С and -36°С under technical system Superpave has been accepted as an indicator of low temperature resistance of the bitumens. The stiffness of the bitumens has been determined on a bending beam rheometer (standard ASTM D 6648-08). Before testing the bitumens have been subjected to the double artificial aging: short-term aging – under standard AASHTO Т 240-13 and long-term aging – under standard ASTM D 6521-08. The nanocarbon bitumen has been prepared in the laboratory of the Kazakhstan Highway Research Institute (KazdorNII) with the use of a road bitumen of the grade BND 70/100 produced by the Pavlodar petrochemical plant (PNHZ) and a nanocarbon powder (2% by weight) manufactured from a coal rock of the deposit “Saryadyr” “Corporation “ON-Olzha” LLP, Akmola region, Kazakhstan). The nanocarbon powder (150-200 nm) has been manufactured by three-stage size reduction of the coal rock: I – a mechanical dispergator (up to 2-3 mm), II – an aerodynamic mill (up to 20 mcm), III – a reactor with a rotating electromagnetic field. The neat bitumens of the grades BND 50/70, BND 70/100, BND 100/130 have been produced by the plants of Kazakhstan and Russia; they satisfy the requirements of the standard ST RK 1373-2013. The modified bitumens have been prepared in the laboratory of KazdorNII with the use of the neat bitumens, 7 types of the polymers, crumb rubber and polyphosphoric acid and they satisfy the requirements of the standard ST RK 2534-2014. It has been determined that the nanocarbon bitumen is one of the most resistant at the low temperatures: -24°С, -30°С and -36°С.


2019 ◽  
Vol 21 (4) ◽  
pp. 317 ◽  
Author(s):  
B.B. Teltayev ◽  
A.A. Kalybai ◽  
G.G. Izmailova ◽  
S.R. Rossi ◽  
E.D. Amirbayev ◽  
...  

Physical and chemical indicators of bitumen quality of grade BND 70/100 with the added carbon nanopowder 2% by weight have been studied by laboratory test methods and analysis. High reaction ability of nanopowder particles and concentration of excess surface and internal energy in them have been determined, which provide the increase of low-temperature resistance, aggregate strength, and improvement of rheological properties of nanostructured bitumen. Essential structure variation has been proved: the increase of asphaltenes and oils content for 9% and 7.2% respectively due to the decrease of resins for 16.2% by weight. Methods have been discussed for preparing a liquid nanocarbon mix, adding of the mix into bitumen and homogenization of the bitumen. Some economic indicators have been represented which influence essentially the reduction for the cost value of the nanostructure bitumen.


1996 ◽  
Vol 14 (8) ◽  
pp. 1003-1006 ◽  
Author(s):  
Osamu Ishizaki-Nishizawa ◽  
Toshio Fujii ◽  
Mizue Azuma ◽  
Keiko Sekiguchi ◽  
Norio Murata ◽  
...  

Soft Matter ◽  
2022 ◽  
Author(s):  
Rui Zhao ◽  
Li Jiang ◽  
Ping Zhang ◽  
Dan Li ◽  
Zhenzhong Guo ◽  
...  

In the recent years, a rapid development of the polymeric hydrogel-based sensors has been witnessed. However, conventional hydrogels often exhibit poor mechanical properties. Additionally, the use of these sensors at...


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