Exacerbated nitrogen limitation ends transient stimulation of grassland productivity by increased precipitation

2017 ◽  
Vol 87 (3) ◽  
pp. 457-469 ◽  
Author(s):  
Haiyan Ren ◽  
Zhuwen Xu ◽  
Forest Isbell ◽  
Jianhui Huang ◽  
Xingguo Han ◽  
...  
Keyword(s):  
Nitrogen Limitation ◽  
Grassland Productivity ◽  
Stimulation Of

scholarly journals Role of auxin homeostasis and response in nitrogen limitation and dark stimulation of adventitious root formation in petunia cuttings

2019 ◽  
Vol 124 (6) ◽  
pp. 1053-1066 ◽  
Author(s):  
Huaiyu Yang ◽  
Yvonne Klopotek ◽  
Mohammad R Hajirezaei ◽  
Siegfried Zerche ◽  
Philipp Franken ◽  
...  
Keyword(s):  
Nitrogen Limitation ◽  
Auxin Transport ◽  
Polar Auxin Transport ◽  
Auxin Homeostasis ◽  
Stem Base ◽  
Auxin Signalling ◽  
Dark Exposure ◽  
Rna Accumulation ◽  
Low Nitrogen ◽  
Stimulation Of

Abstract Background and Aims Adventitious root (AR) formation in Petunia hybrida is inhibited by low nitrogen fertilization of stock plants but promoted by dark incubation of cuttings before planting. We investigated whether the plant hormone auxin is involved in nitrogen- and dark-mediated AR formation. Methods Concentrations of indole-3-acetic acid (IAA) and RNA accumulation of genes controlling auxin homeostasis and function were monitored in the stem base in response to high versus low nitrogen supply to stock plants and to temporal dark vs. light exposure of cuttings by use of GC-MS/MS, a petunia-specific microarray and quantitative RT-PCR. Auxin source capacity, polar auxin transport in cuttings and auxin concentration in the rooting zone were manipulated to investigate the functional contribution of auxin homeostasis and response to the effects of nitrogen fertilization and dark exposure on rooting. Key Results The nitrogen content of cuttings had only a marginal effect on IAA concentration in the stem base. Dark incubation enhanced the accumulation of IAA in the stem base during AR induction independent of nitrogen level. Early IAA accumulation in the dark depended on the upper shoot as an auxin source and was enhanced after apical IAA supply. Dark exposure stimulated RNA accumulation of auxin-related genes. In particular, expression of Ph-PIN1 and of genes controlling auxin signalling, including Ph-IAA14, Ph-ARF8, Ph-ARF10 and Ph-SAUR14, was enhanced, while the latter four were repressed in nitrogen-limited cuttings, particularly in the dark. Dark stimulation of rooting depended on polar auxin transport. Basal auxin application partially substituted the effect of dark exposure on rooting, whereas the auxin response of AR formation was strongly depressed by nitrogen limitation. Conclusions Increased auxin delivery from the upper shoot and enhanced auxin signalling in the stem base contribute to dark-stimulated AR formation, while nitrogen limitation inhibits AR formation downstream of the auxin signal.

scholarly journals Stimulation of Hydrogen Photoproduction in Chlorella sorokiniana Subjected to Simultaneous Nitrogen Limitation and Sulfur- and/or Phosphorus-Deprivation

2018 ◽  
Vol 12 (4) ◽  
pp. 1719-1727 ◽  
Author(s):  
Piyawat Pongpadung ◽  
Litao Zhang ◽  
Ramaraj Sathasivam ◽  
Kittisak Yokthongwattana ◽  
Niran Juntawong ◽  
...  
Keyword(s):  
Nitrogen Limitation ◽  
Chlorella Sorokiniana ◽  
Phosphorus Deprivation ◽  
Hydrogen Photoproduction ◽  
Stimulation Of

Effects of 5-5'-Diphenyl-2-thiohydantoin (DPTH) and Thyroxine on the Ultrastructure and Chemical Composition of Rat Liver

1971 ◽  
Vol 29 ◽  
pp. 570-571
Author(s):  
E. A. Elfont ◽  
R. B. Tobin ◽  
D. G. Colton ◽  
M. A. Mehlman
Keyword(s):  
Chemical Composition ◽  
Rat Liver ◽  
Future Study ◽  
Mode Of Action ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Effective Inhibitor ◽  
Biochemical Effects ◽  
Glycerophosphate Dehydrogenase ◽  
Stimulation Of

Summary5,-5'-diphenyl-2-thiohydantoin (DPTH) is an effective inhibitor of thyroxine (T4) stimulation of α-glycerophosphate dehydrogenase in rat liver mitochondria. Because this finding indicated a possible tool for future study of the mode of action of thyroxine, the ultrastructural and biochemical effects of DPTH and/or thyroxine on rat liver mere investigated.Rats were fed either standard or DPTH (0.06%) diet for 30 days before T4 (250 ug/kg/day) was injected. Injection of T4 occurred daily for 10 days prior to sacrifice. After removal of the liver and kidneys, part of the tissue was frozen at -50°C for later biocheailcal analyses, while the rest was prefixed in buffered 3.5X glutaraldehyde (390 mOs) and post-fixed in buffered 1Z OsO4 (376 mOs). Tissues were embedded in Araldlte 502 and the sections examined in a Zeiss EM 9S.Hepatocytes from hyperthyroid rats (Fig. 2) demonstrated enlarged and more numerous mitochondria than those of controls (Fig. 1). Glycogen was almost totally absent from the cytoplasm of the T4-treated rats.

Gap junctions in the prothoracic glands of the tobacco hornworm, Manduca sexta

1992 ◽  
Vol 50 (1) ◽  
pp. 706-707
Author(s):  
Ji-da Dai ◽  
M. Joseph Costello ◽  
Lawrence I. Gilbert
Keyword(s):  
Gap Junctions ◽  
Small Molecules ◽  
Manduca Sexta ◽  
Freeze Fracture ◽  
Cell Communication ◽  
Cellular Level ◽  
Thin Sections ◽  
Prothoracic Glands ◽  
Polyhydroxylated Steroids ◽  
Stimulation Of

Insect molting and metamorphosis are elicited by a class of polyhydroxylated steroids, ecdysteroids, that originate in the prothoracic glands (PGs). Prothoracicotropic hormone stimulation of steroidogenesis by the PGs at the cellular level involves both calcium and cAMP. Cell-to-cell communication mediated by gap junctions may play a key role in regulating signal transduction by controlling the transmission of small molecules and ions between adjacent cells. This is the first report of gap junctions in the PGs, the evidence obtained by means of SEM, thin sections and freeze-fracture replicas.

Activator protein-1 is necessary for angiotensin-II stimulation of human adrenocorticotropin receptor gene transcription

2001 ◽  
Vol 268 (6) ◽  
pp. 1802-1810
Author(s):  
Danielle Naville ◽  
Estelle Bordet ◽  
Marie-Claude Berthelon ◽  
Philippe Durand ◽  
Martine Begeot
Keyword(s):  
Angiotensin Ii ◽  
Gene Transcription ◽  
Receptor Gene ◽  
Activator Protein 1 ◽  
Activator Protein ◽  
Stimulation Of
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