scholarly journals Mutation of the Rice Narrow leaf1 Gene, Which Encodes a Novel Protein, Affects Vein Patterning and Polar Auxin Transport

2008 ◽  
Vol 147 (4) ◽  
pp. 1947-1959 ◽  
Author(s):  
Jing Qi ◽  
Qian Qian ◽  
Qingyun Bu ◽  
Shuyu Li ◽  
Qian Chen ◽  
...  
Keyword(s):  
Auxin Transport ◽  
Polar Auxin Transport ◽  
Vein Patterning ◽  
Novel Protein

scholarly journals Polar auxin transport dynamics of primary and secondary vein patterning in dicot leaves

2021 ◽  
Author(s):  
David M Holloway ◽  
Carol L Wenzel
Keyword(s):  
Auxin Transport ◽  
Leaf Growth ◽  
Cellular Level ◽  
Polar Auxin Transport ◽  
Secondary Vein ◽  
Neighbouring Cell ◽  
Transport Dynamics ◽  
Leaf Vein ◽  
Auxin Flux ◽  
Vein Patterning

Abstract The growth regulator auxin plays a central role in the phyllotaxy, shape, and venation patterns of leaves. The auxin spatial localization underlying these phenomena involves polar auxin transport (PAT) at the cellular level, particularly the preferential allocation of PIN efflux proteins to certain areas of the plasma membrane. Two general mechanisms have been studied: an up-the-gradient (UTG) allocation dependent on neighbouring-cell auxin concentrations, and a with-the-flux (WTF) allocation dependent on the flow of auxin across walls. We have developed a combined UTG+WTF model to quantify the observed auxin flows both towards (UTG) and away from (WTF) auxin maxima during primary and secondary vein patterning in leaves. The model simulates intracellular and membrane kinetics and intercellular transport, and is solved for a 2D leaf of several hundred cells. In addition to normal development, modelling of increasing PAT inhibition generates, as observed experimentally: a switch from several distinct vein initiation sites to many less-distinct sites; a delay in vein canalization; inhibited connection of new veins to old; and finally loss of patterning in the margin, loss of vein extension, and confinement of auxin to the margin. The model generates the observed formation of discrete auxin maxima at leaf vein sources and shows the dependence of secondary vein patterning on the efficacy of auxin flux through cells. Simulations of vein patterning and leaf growth further indicate that growth itself may bridge the spatial scale from the cell-cell resolution of the PIN-auxin dynamics to vein patterns on the whole-leaf scale.

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
Sign in / Sign up

Export Citation Format

Share Document