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1.
Formation of a Tree having a Low Lignin Content 总被引:2,自引:0,他引:2
Received 30 September 2001/ Accepted in revised form 26 October 2001 相似文献
2.
Kenji Tomioka Kenji Yamada Shinya Yokoyama Yoshihiko Chiba 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1991,169(3):291-298
The coupling mechanism between the bilaterally paired optic lobe circadian pacemakers in the cricket Gryllus bimaculatus was investigated by recording locomotor activity, under constant light or constant red light, after the optic nerve was unilaterally severed.
These results suggest that the 2 optic lobe pacemakers weakly couple to one another and that the cricket maintains a stable temporal structure in its behavior through the phase-dependent mututal inhibition of activity and the phase-dependent freerunning period modulation. 相似文献
1. | The majority (about 70%) of the animals showed a locomotor rhythm with 2 rhythmic components; one freerunning with a period of 25.33 ± 0.41 (SD) h and the other with 24.36 ± 0.37 (SD) h under constant light (Fig. 3A). |
2. | Removal of the intact side optic lobe abolished the longer period component (Fig. 4A), while the operation on the operated side caused a reverse effect (Fig. 4B), indicating that the longer and the shorter period components are driven by the pacemaker on the intact and the operated side, respectively. |
3. | The activity driven by a pacemaker was inhibited during the subjective day of the contralateral pacemaker (circadian time 0–10, Fig. 5). |
4. | The freerunning periods of the two components were not constant but varied as a function of the mutual phase angle relationship (Figs. 3A, 7, 8). |
3.
Kimio Fukami Shinya Nishimura Masamichi Ogusa Miki Asada Toshitaka Nishijima 《Hydrobiologia》1997,358(1-3):245-249
A continuous culture system for a benthic food diatom Nitzschia sp. wasestablished by using properties of high nutrient and clean of deep seawater(DSW). DSW collected from 320 m depth in Muroto City, Japan, was introducedinto a glass-pipe bioreactor (14 cm length, 3 cm diam.) containing glassbeads of 0.5 cm diam. as substrata for the alga, and it was incubated at18°C · 80Em–2sec–1 · L:D=14:10. The chlorophyll a yield of benthicdiatoms in a reactor as a unit of surface area of the substratum was only0.001–0.003 g cm–2 when the flow rate of DSW was 0(batch culture conditions). However, when DSW was supplied continuously to areactor, the yield increased to 1.4 g-chl.a cm–2 alongwith the increase in flow rate of DSW. Moreover, amounts of chl.a washed outof the system were negligible, 0.0014 to 0.0045%, even though theflow rate of DSW was as much as 25 times h–1, suggesting thatsloughing of benthic diatoms from the substratum was minimized. Although theyield of diatoms fluctuated significantly at the time that the DSW wascollected, the variation could be minimized by increasing the flow rate ofDSW. These results indicate that the continuous culturing system with DSWsupports the stable and effective mass culture of benthic food diatom. 相似文献
4.
Shinya Nomoto Michiaki Takasaki Hiroshi Naraoka Kaoru Harada 《Origins of life and evolution of the biosphere》1984,14(1-4):123-130
Flames of flammable gases, when blown against a surface of an aqueous solution of organic compounds, were found to induce oxidation as well as other reactions in the solution. This reaction would be regarded as a new model for formation of bioorganic molecules in the primitive hydrosphere exposed to some radical-containing atmosphere. 相似文献
5.
Noriyuki Nakayama Issay Narumi Shinya Nakamoto Hiroshi Kihara 《Biotechnology letters》1992,14(8):649-652
Summary A new shuttle vector was constructed by inserting a 3.1 kbp-DNA fragment from thermophilicBacillus sp. plasmid pIH41 intoEscherichia coli plasmid pUC18. The resultant hybrid replicates in bothE. coli andB. stearothermophilus. This vector has ten unique restriction sites within a part oflacZ gene. Insertion of foreign DNA into these sites can be readily detected by a coloration method. 相似文献
6.
A system suitable for ultraviolet imaging densitometry of two-dimensional electrophoretic gels that are unstained is described, together with its applications. A flying-spot densitometer linked with a personal computer was used for data acquisition, generation of mapping data, and image processing. Randomly distributed zones of proteins on two-dimensional gels were detected at 280 nm without being stained by two-dimensional scanning, and the densitometric value of each pixel (0.2 x 0.2 mm) was memorized by the computer, which generated a mapping pattern with density contours. The amount and densitometric value of cytochrome c had a linear relationship in the range of 2-200 micrograms. Zone locations of bovine liver proteins separated on two-dimensional gels were indicated on a map expressed in X-Y coordinates, and the pIs and molecular weights could be calculated from the map by use of pI and molecular weight markers on the same gel. 相似文献
7.
Delphine Mnard Leonard Blaschek Konstantin Kriechbaum Cheng Choo Lee Henrik Serk Chuantao Zhu Alexander Lyubartsev Nuoendagula Zoltn Bacsik Lennart Bergstrm Aji Mathew Shinya Kajita Edouard Pesquet 《The Plant cell》2022,34(12):4877
The biopolymer lignin is deposited in the cell walls of vascular cells and is essential for long-distance water conduction and structural support in plants. Different vascular cell types contain distinct and conserved lignin chemistries, each with specific aromatic and aliphatic substitutions. Yet, the biological role of this conserved and specific lignin chemistry in each cell type remains unclear. Here, we investigated the roles of this lignin biochemical specificity for cellular functions by producing single cell analyses for three cell morphotypes of tracheary elements, which all allow sap conduction but differ in their morphology. We determined that specific lignin chemistries accumulate in each cell type. Moreover, lignin accumulated dynamically, increasing in quantity and changing in composition, to alter the cell wall biomechanics during cell maturation. For similar aromatic substitutions, residues with alcohol aliphatic functions increased stiffness whereas aldehydes increased flexibility of the cell wall. Modifying this lignin biochemical specificity and the sequence of its formation impaired the cell wall biomechanics of each morphotype and consequently hindered sap conduction and drought recovery. Together, our results demonstrate that each sap-conducting vascular cell type distinctly controls their lignin biochemistry to adjust their biomechanics and hydraulic properties to face developmental and environmental constraints.During the development of each vascular cell, specific lignin chemistries control their biomechanics and water conduction properties to face environmental changes.IN A NUTSHELL Background: Lignin comprises multiple cell wall–localized aromatic polymers that are essential for vascular plants to conduct water and strengthen their organs. It has long been thought that lignin was randomly and nonspecifically assembled to provide mechanical strengthening and waterproofing to cells by filling-up the empty spaces in the cell walls. However, the different cell types and morphotypes forming the different sap-conducting pipes and their cell wall layers (inner vs. outer layer) exhibit specific lignin chemistries that are conserved among plant species. We, therefore, investigated the function of these specific lignin chemistries at the cell and cell wall layer levels for the different sap-conducting pipes in plants. Question: What is the function of a specific lignin chemistry for the different plant sap-conducting pipe cells? Can changes in the lignin chemistry of sap-conducting cells affect their hydraulic capacity when facing environmental conditions such as drought? Findings: We answered these questions by changing lignin levels and composition, using drugs to block lignin formation, and/or genetic engineering to switch off genes, in three complementary systems: (1) isolated cells grown in test tubes that we can trigger to become sap conduits, (2) annual plants, and (3) hardwood trees. We show that lignin chemistry is specific to each cell morphotype and changes during cell maturation, modifying the amount of lignin, the chemical composition of lignin units, and the position of these units in the longer polymer. These specific lignin chemistries are required for the proper function of each cell morphotype to properly conduct the sap and strengthen plant organs. Modifying the amount, the composition, and the time when specific units with distinct chemistry are incorporated in lignin of each cell morphotype has dramatic effects, causing defects in sap conduit hydraulic and biomechanical properties. The ratio between the different chemical units of lignin needs to be fine-tuned to adjust plant sap conduction and mechanical strengthening. Thus, changes in the proportion of lignin units with distinct chemistries confer different hydraulic and mechanical properties enabling plants to better resist and/or recover from drought. We also revealed that increases in the proportion of lignin units with aldehyde modulate plant pipe hydraulic and mechanical properties. Next steps: We are now working to identify and understand the molecular mechanisms that control the formation of specific lignin chemistries in distinct sites and times during the development of the different cell wall layers in each cell type and morphotype. 相似文献
8.
The synthesis of the OmpF porin in Escherichia coli K-12 was highly and reversibly inhibited by 5 mM salicylate in the bacterial growth medium, and salicylate also inhibited the OmpC porin synthesis, although only weakly. The full expression of the salicylate effect was presumed to require the ompB gene product on comparison between the wild type and ompB mutant strains. The salicylate effect was also observed for the porin protein synthesis in Klebsiella pneumoniae and Serratia marcescens, although an ompB-like gene remains to be identified in both species. 相似文献
9.
Togi S Ikeda O Kamitani S Nakasuji M Sekine Y Muromoto R Nanbo A Oritani K Kawai T Akira S Matsuda T 《The Journal of biological chemistry》2011,286(21):19170-19177
10.
Many scientists complain that the current funding situation is dire. Indeed, there has been an overall decline in support in funding for research from the National Institutes of Health and the National Science Foundation. Within the Drosophila field, some of us question how long this funding crunch will last as it demotivates principal investigators and perhaps more importantly affects the long-term career choice of many young scientists. Yet numerous very interesting biological processes and avenues remain to be investigated in Drosophila, and probing questions can be answered fast and efficiently in flies to reveal new biological phenomena. Moreover, Drosophila is an excellent model organism for studies that have translational impact for genetic disease and for other medical implications such as vector-borne illnesses. We would like to promote a better collaboration between Drosophila geneticists/biologists and human geneticists/bioinformaticians/clinicians, as it would benefit both fields and significantly impact the research on human diseases. 相似文献