scholarly journals The Dynamics of Radio-Cesium in Soils and Mechanism of Cesium Uptake Into Higher Plants: Newly Elucidated Mechanism of Cesium Uptake Into Rice Plants

2020 ◽  
Vol 11 ◽  
Author(s):  
Hiroki Rai ◽  
Miku Kawabata
2020 ◽  
Vol 71 (20) ◽  
pp. 6491-6511
Author(s):  
Kadis Mujiono ◽  
Tilisa Tohi ◽  
Islam S Sobhy ◽  
Yuko Hojo ◽  
Nhan Thanh Ho ◽  
...  

Abstract We examined the role of ethylene in the production of rice (Oryza sativa) volatile organic compounds (VOCs), which act as indirect defense signals against herbivores in tritrophic interactions. Rice plants were exposed to exogenous ethylene (1 ppm) after simulated herbivory, which consisted of mechanical wounding supplemented with oral secretions (WOS) from the generalist herbivore larva Mythimna loreyi. Ethylene treatment highly suppressed VOCs in WOS-treated rice leaves, which was further corroborated by the reduced transcript levels of major VOC biosynthesis genes in ethylene-treated rice. In contrast, the accumulation of jasmonates (JA), known to control VOCs in higher plants, and transcript levels of primary JA response genes, including OsMYC2, were not largely affected by ethylene application. At the functional level, flooding is known to promote internode elongation in young rice via ethylene signaling. Consistent with the negative role of ethylene on VOC genes, the accumulation of VOCs in water-submerged rice leaves was suppressed. Furthermore, in mature rice plants, which naturally produce less volatiles, VOCs could be rescued by the application of the ethylene perception inhibitor 1-methylcyclopropene. Our data suggest that ethylene acts as an endogenous suppressor of VOCs in rice plants during development and under stress.


Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.


Author(s):  
James Cronshaw ◽  
Jamison E. Gilder

Adenosine triphosphatase (ATPase) activity has been shown to be associated with numerous physiological processes in both plants and animal cells. Biochemical studies have shown that in higher plants ATPase activity is high in cell wall preparations and is associated with the plasma membrane, nuclei, mitochondria, chloroplasts and lysosomes. However, there have been only a few ATPase localization studies of higher plants at the electron microscope level. Poux (1967) demonstrated ATPase activity associated with most cellular organelles in the protoderm cells of Cucumis roots. Hall (1971) has demonstrated ATPase activity in root tip cells of Zea mays. There was high surface activity largely associated with the plasma membrane and plasmodesmata. ATPase activity was also demonstrated in mitochondria, dictyosomes, endoplasmic reticulum and plastids.


Author(s):  
A. E. Hotchkiss ◽  
A. T. Hotchkiss ◽  
R. P. Apkarian

Multicellular green algae may be an ancestral form of the vascular plants. These algae exhibit cell wall structure, chlorophyll pigmentation, and physiological processes similar to those of higher plants. The presence of a vascular system which provides water, minerals, and nutrients to remote tissues in higher plants was believed unnecessary for the algae. Among the green algae, the Chaetophorales are complex highly branched forms that might require some means of nutrient transport. The Chaetophorales do possess apical meristematic groups of cells that have growth orientations suggestive of stem and root positions. Branches of Chaetophora incressata were examined by the scanning electron microscope (SEM) for ultrastructural evidence of pro-vascular transport.


1995 ◽  
Vol 93 (4) ◽  
pp. 617-623 ◽  
Author(s):  
Shu-Chen Grace Chen ◽  
Sang-Pin Wu ◽  
Pang-Kuo Lo ◽  
Dir-Pu Mon ◽  
Long-Fang Oliver Chen
Keyword(s):  

2018 ◽  
Vol 159 (18) ◽  
pp. 703-708
Author(s):  
Gábor Vasas

Abstract: More than 90% of herbal products and herbal medicines have been derived from higher plants recently, but due to independent circumstances, several photosynthetic microalgal species are in focus in this point of view. In the last 50 years, many carbohydrate-, peptide-, terpenoid-, alkaloid- and phenol-type components were described from algae because of the developing structural determination and analytical methods, algae mass production and also artificial algae technologies. At the same time, based partly on traditional causes and partly on the clinical and preclinical data of today, some dried products of algae are directly used as food supplements. Hereinafter, the historical background, economic significance and metabolic background of the mostly used microalgal species will be reviewed. The diverse metabolite production of these organisms will be demonstrated by some molecules with special bioactivity. Several preclinical and clinical studies will be described relating to the microalgal species Spirulina sp., Chlorella sp., Haematococcus sp. and Dunaliella sp. Orv Hetil. 2018; 159(18): 703–708.


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