apical hook
Recently Published Documents


TOTAL DOCUMENTS

71
(FIVE YEARS 19)

H-INDEX

19
(FIVE YEARS 4)

2022 ◽  
Vol 8 (2) ◽  
Author(s):  
Minmin Du ◽  
Firas Bou Daher ◽  
Yuanyuan Liu ◽  
Andrew Steward ◽  
Molly Tillmann ◽  
...  

Auxin concentration–dependent cell expansion coordinates hypocotyl elongation and apical hook development for soil emergence.


Author(s):  
Yang Peng ◽  
Dan Zhang ◽  
Yuping Qiu ◽  
Zhina Xiao ◽  
Yusi Ji ◽  
...  
Keyword(s):  

Author(s):  
Yalikunjiang Aizezi ◽  
Huazhang Shu ◽  
Linlin Zhang ◽  
Hongming Zhao ◽  
Yang Peng ◽  
...  

Abstract The apical hook is indispensable for protecting the delicate shoot apical meristem while dicot seedlings emerge from soil after germination in darkness. The development of the apical hook is co-ordinately regulated by multiple phytohormones and environmental factors. Yet, a holistic understanding of the spatial–temporal interactions between different phytohormones and environmental factors remains to be achieved. Using a chemical genetic approach, we identified kinetin riboside, as a proxy of kinetin, which promotes apical hook development of Arabidopsis thaliana in a partially ethylene-signaling-independent pathway. Further genetic and biochemical analysis revealed that cytokinin is able to regulate apical hook development via post-transcriptional regulation of the PHYTOCHROME INTERACTING FACTORs (PIFs), together with its canonical roles in inducing ethylene biosynthesis. Dynamic observations of apical hook development processes showed that ETHYLENE INSENSITVE3 (EIN3) and EIN3-LIKE1 (EIL1) are necessary for the exaggeration of hook curvature in response to cytokinin, while PIFs are crucial for the cytokinin-induced maintenance of hook curvature in darkness. Furthermore, these two families of transcription factors display divergent roles in light-triggered hook opening. Our findings reveal that cytokinin integrates ethylene signaling and light signaling via EIN3/EIL1 and PIFs, respectively, to dynamically regulate apical hook development during early seedling development.


2021 ◽  
Author(s):  
Jia Deng ◽  
Xiangfeng Wang ◽  
Ziqiang Liu ◽  
Tonglin Mao

AbstractThe unique apical hook in dicotyledonous plants protects the shoot apical meristem and cotyledons when seedlings emerge through the soil. Its formation involves differential cell growth under the coordinated control of plant hormones, especially ethylene and auxin. Microtubules are essential players in plant cell growth that are regulated by multiple microtubule-associated proteins (MAPs). However, the role and underlying mechanisms of MAP-microtubule modules in differential cell growth are poorly understood. In this study, we found that the previously uncharacterized Arabidopsis MAP WAVE-DAMPENED2-LIKE4 (WDL4) protein plays a positive role in apical hook opening. WDL4 exhibits a temporal expression pattern during hook development in dark-grown seedlings that is directly regulated by ethylene signaling. WDL4 mutants showed a delayed hook opening phenotype while overexpression of WDL4 resulted in enhanced hook opening. In particular, wdl4-1 mutants exhibited stronger auxin accumulation in the concave side of the apical hook. Furthermore, the regulation of the auxin maxima and trafficking of the auxin efflux carriers PIN-FORMED1 (PIN1) and PIN7 in the hook region is critical for WDL4-mediated hook opening. Together, our study demonstrates that WDL4 positively regulates apical hook opening by modulating auxin distribution, thus unraveling a mechanism for MAP-mediated differential plant cell growth.


2020 ◽  
Vol 32 (12) ◽  
pp. 3792-3811
Author(s):  
Jiajun Wang ◽  
Ning Sun ◽  
Fangfang Zhang ◽  
Renbo Yu ◽  
Haodong Chen ◽  
...  
Keyword(s):  

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Naveen Sharma ◽  
Chanderkant Chaudhary ◽  
Paramjit Khurana

Abstract Myo-inositol is a ubiquitous metabolite of plants. It is synthesized by a highly conserved enzyme L-myo-inositol phosphate synthase (MIPS; EC 5.5.1.4). Myo-inositol is well characterized during abiotic stress tolerance but its role during growth and development is unclear. In this study, we demonstrate that the apical hook maintenance and hypocotyl growth depend on myo-inositol. We discovered the myo-inositol role during hook formation and its maintenance via ethylene pathway in Arabidopsis by supplementation assays and qPCR. Our results suggest an essential requirement of myo-inositol for mediating the ethylene response and its interaction with brassinosteroid to regulate the skotomorphogenesis. A model is proposed outlining how MIPS regulates apical hook formation and hypocotyl growth.


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.


Sign in / Sign up

Export Citation Format

Share Document