scholarly journals Root gravity response module guides differential growth determining both root bending and apical hook formation in Arabidopsis

Development ◽  
2019 ◽  
Vol 146 (17) ◽  
pp. dev175919 ◽  
Author(s):  
Qiang Zhu ◽  
Marçal Gallemí ◽  
Jiří Pospíšil ◽  
Petra Žádníková ◽  
Miroslav Strnad ◽  
...  
Nature ◽  
2019 ◽  
Vol 568 (7751) ◽  
pp. 240-243 ◽  
Author(s):  
Min Cao ◽  
Rong Chen ◽  
Pan Li ◽  
Yongqiang Yu ◽  
Rui Zheng ◽  
...  

2020 ◽  
Vol 21 (17) ◽  
pp. 6438
Author(s):  
Miriam Führer ◽  
Angelika Gaidora ◽  
Peter Venhuizen ◽  
Jedrzej Dobrogojski ◽  
Chloé Béziat ◽  
...  

Plants adjust their architecture to a constantly changing environment, requiring adaptation of differential growth. Despite their importance, molecular switches, which define growth transitions, are largely unknown. Apical hook development in dark grown Arabidopsis thaliana (A. thaliana) seedlings serves as a suitable model for differential growth transition in plants. Here, we show that the phytohormone auxin counteracts the light-induced growth transition during apical hook opening. We, subsequently, identified genes which are inversely regulated by light and auxin. We used in silico analysis of the regulatory elements in this set of genes and subsequently used natural variation in gene expression to uncover correlations between underlying transcription factors and the in silico predicted target genes. This approach uncovered that MADS box transcription factor AGAMOUS-LIKE 8 (AGL8)/FRUITFULL (FUL) modulates apical hook opening. Our data shows that transient FUL expression represses the expression of growth stimulating genes during early phases of apical hook development and therewith guards the transition to growth promotion for apical hook opening. Here, we propose a role for FUL in setting tissue identity, thereby regulating differential growth during apical hook development.


2013 ◽  
Vol 4 ◽  
Author(s):  
Mohamad Abbas ◽  
David Alabadí ◽  
Miguel A. Blázquez

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Matyáš Fendrych ◽  
Jeffrey Leung ◽  
Jiří Friml

Despite being composed of immobile cells, plants reorient along directional stimuli. The hormone auxin is redistributed in stimulated organs leading to differential growth and bending. Auxin application triggers rapid cell wall acidification and elongation of aerial organs of plants, but the molecular players mediating these effects are still controversial. Here we use genetically-encoded pH and auxin signaling sensors, pharmacological and genetic manipulations available for Arabidopsis etiolated hypocotyls to clarify how auxin is perceived and the downstream growth executed. We show that auxin-induced acidification occurs by local activation of H+-ATPases, which in the context of gravity response is restricted to the lower organ side. This auxin-stimulated acidification and growth require TIR1/AFB-Aux/IAA nuclear auxin perception. In addition, auxin-induced gene transcription and specifically SAUR proteins are crucial downstream mediators of this growth. Our study provides strong experimental support for the acid growth theory and clarified the contribution of the upstream auxin perception mechanisms.


2016 ◽  
Vol 28 (10) ◽  
pp. 2464-2477 ◽  
Author(s):  
Petra Žádníková ◽  
Krzysztof Wabnik ◽  
Anas Abuzeineh ◽  
Marçal Gallemi ◽  
Dominique Van Der Straeten ◽  
...  

Development ◽  
1999 ◽  
Vol 126 (16) ◽  
pp. 3661-3668 ◽  
Author(s):  
V. Raz ◽  
J.R. Ecker

Arabidopsis seedlings develop a hook-like structure at the apical part of the hypocotyl when grown in darkness. Differential cell growth processes result in the curved hypocotyl hook. Time-dependent analyses of the hypocotyl showed that the apical hook is formed during an early phase of seedling growth and is maintained in a sequential phase by a distinct process. Based on developmental genetic analyses of hook-affected mutants, we show that the hookless mutants (hls1, cop2) are involved in an early aspect of hook development. From time-dependent analyses of ethylene-insensitive mutants, later steps in hook maintenance were found to be ethylene sensitive. Regulation of differential growth was further studied through examination of the spatial pattern of expression of two hormone-regulated genes: an ethylene biosynthetic enzyme and the ethylene receptor ETR1. Accumulation of mRNA for AtACO2, a novel ACC (1-aminocyclopropane-1-carboxylic acid) oxidase gene, occurred within cells predominantly located on the outer-side of the hook and was tightly correlated with ethylene-induced exaggeration in the curvature of the hook. ETR1 expression in the apical hook, however, was reduced by ethylene treatment. Based on the expression pattern of ETR1 and AtACO2 in the hook-affected mutants, a model for hook development and maintenance is proposed.


Author(s):  
P.T. Nguyen ◽  
C. Uphoff ◽  
C.L. Stinemetz

Considerable evidence suggest that the calcium-binding protein calmodulin (CaM) may mediate calcium action and/or transport important in the gravity response of plants. Calmodulin is present in both shoots and roots and is capable of regulating calcium transport in plant vesicles. In roots calmodulin is concentrated in the tip, the gravisensing region of the root; and is reported to be closely associated with amyloplasts, organelles suggested to play a primary role in gravi-perception. Inhibitors of CaM such as chlorpromazine, calmidazolium, and compound 48/80 interfere with the gravitropic response of both snoots and roots. The magnitude of the inhibition corresponded well with the extent to which the drug binds to endogenous CaM. Compound 48/80 and calmidazolium block gravi-induced changes in electrical currents across root tips, a phenomenon thought to be associated with the sensing of the gravity stimulus.In this study, we have investigated the subcellular distribution of CaM in graviresponsive and non-graviresponsive root caps of the maize cultivar Merit.


2001 ◽  
Vol 120 (5) ◽  
pp. A338-A339
Author(s):  
Z FAN ◽  
H WU ◽  
S PATEL ◽  
M ZENILMAN

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