scholarly journals Effects of osmotic stress on polar auxin transport in Avena mesocotyl sections

Planta ◽  
1979 ◽  
Vol 145 (2) ◽  
pp. 113-117 ◽  
Author(s):  
A. R. Sheldrake
Keyword(s):  
Osmotic Stress ◽  
Auxin Transport ◽  
Polar Auxin Transport

scholarly journals Membrane Sterol Composition in Arabidopsis thaliana Affects Root Elongation via Auxin Biosynthesis

2021 ◽  
Vol 22 (1) ◽  
pp. 437
Author(s):  
Meng Wang ◽  
Panpan Li ◽  
Yao Ma ◽  
Xiang Nie ◽  
Markus Grebe ◽  
...  
Keyword(s):  
Root Elongation ◽  
Auxin Transport ◽  
Sterol Composition ◽  
Polar Auxin Transport ◽  
Sterol Biosynthesis ◽  
Auxin Biosynthesis ◽  
Root Tip ◽  
Auxin Signaling ◽  
Auxin Response ◽  
Short Root

Plant membrane sterol composition has been reported to affect growth and gravitropism via polar auxin transport and auxin signaling. However, as to whether sterols influence auxin biosynthesis has received little attention. Here, by using the sterol biosynthesis mutant cyclopropylsterol isomerase1-1 (cpi1-1) and sterol application, we reveal that cycloeucalenol, a CPI1 substrate, and sitosterol, an end-product of sterol biosynthesis, antagonistically affect auxin biosynthesis. The short root phenotype of cpi1-1 was associated with a markedly enhanced auxin response in the root tip. Both were neither suppressed by mutations in polar auxin transport (PAT) proteins nor by treatment with a PAT inhibitor and responded to an auxin signaling inhibitor. However, expression of several auxin biosynthesis genes TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS1 (TAA1) was upregulated in cpi1-1. Functionally, TAA1 mutation reduced the auxin response in cpi1-1 and partially rescued its short root phenotype. In support of this genetic evidence, application of cycloeucalenol upregulated expression of the auxin responsive reporter DR5:GUS (β-glucuronidase) and of several auxin biosynthesis genes, while sitosterol repressed their expression. Hence, our combined genetic, pharmacological, and sterol application studies reveal a hitherto unexplored sterol-dependent modulation of auxin biosynthesis during Arabidopsis root elongation.

scholarly journals Dim-Red-Light-Induced Increase in Polar Auxin Transport in Cucumber Seedlings

1998 ◽  
Vol 116 (4) ◽  
pp. 1505-1513 ◽  
Author(s):  
James R. Shinkle ◽  
Rajan Kadakia ◽  
Alan M. Jones
Keyword(s):  
Auxin Transport ◽  
Red Light ◽  
Polar Auxin Transport ◽  
Cucumber Seedlings

scholarly journals Auxin minimum triggers the developmental switch from cell division to cell differentiation in the Arabidopsis root

2017 ◽  
Vol 114 (36) ◽  
pp. E7641-E7649 ◽  
Author(s):  
Riccardo Di Mambro ◽  
Micol De Ruvo ◽  
Elena Pacifici ◽  
Elena Salvi ◽  
Rosangela Sozzani ◽  
...  
Keyword(s):  
Cell Division ◽  
Auxin Transport ◽  
Positional Information ◽  
Polar Auxin Transport ◽  
Arabidopsis Root ◽  
Polar Transport ◽  
Stringent Control ◽  
Auxin Polar Transport ◽  
Multicellular Organisms ◽  
Developmental Switch

In multicellular organisms, a stringent control of the transition between cell division and differentiation is crucial for correct tissue and organ development. In the Arabidopsis root, the boundary between dividing and differentiating cells is positioned by the antagonistic interaction of the hormones auxin and cytokinin. Cytokinin affects polar auxin transport, but how this impacts the positional information required to establish this tissue boundary, is still unknown. By combining computational modeling with molecular genetics, we show that boundary formation is dependent on cytokinin’s control on auxin polar transport and degradation. The regulation of both processes shapes the auxin profile in a well-defined auxin minimum. This auxin minimum positions the boundary between dividing and differentiating cells, acting as a trigger for this developmental transition, thus controlling meristem size.

Reduced Naphthylphthalamic Acid Binding in the tir3 Mutant of Arabidopsis Is Associated with a Reduction in Polar Auxin Transport and Diverse Morphological Defects

1997 ◽  
Vol 9 (5) ◽  
pp. 745 ◽  
Author(s):  
Max Ruegger ◽  
Elizabeth Dewey ◽  
Lawrence Hobbie ◽  
Dana Brown ◽  
Paul Bernasconi ◽  
...  
Keyword(s):  
Auxin Transport ◽  
Polar Auxin Transport ◽  
Morphological Defects ◽  
Naphthylphthalamic Acid

Polar auxin transport — old questions and new concepts?

2002 ◽  
pp. 273-284 ◽  
Author(s):  
Jiří Friml ◽  
Klaus Palme
Keyword(s):  
Auxin Transport ◽  
Polar Auxin Transport ◽  
New Concepts
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