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 YUCCA9-Mediated Auxin Biosynthesis and Polar Auxin Transport Synergistically Regulate Regeneration of Root Systems Following Root Cutting

2017 ◽  
Vol 58 (10) ◽  
pp. 1710-1723 ◽  
Author(s):  
Dongyang Xu ◽  
Jiahang Miao ◽  
Emi Yumoto ◽  
Takao Yokota ◽  
Masashi Asahina ◽  
...  
Keyword(s):  
Auxin Transport ◽  
Root Systems ◽  
Polar Auxin Transport ◽  
Auxin Biosynthesis ◽  
Root Cutting

scholarly journals Rapid auxin-mediated phosphorylation of Myosin regulates trafficking and polarity in Arabidopsis

2021 ◽  
Author(s):  
Huibin Han ◽  
Inge Verstraeten ◽  
Mark Roosjen ◽  
Ewa Mazur ◽  
Nikola Rydza ◽  
...  
Keyword(s):  
Plant Development ◽  
Auxin Transport ◽  
Adaptor Protein ◽  
Feedback Regulation ◽  
Cellular Responses ◽  
Central Component ◽  
Auxin Signaling ◽  
Auxin Response ◽  
Cellular Processes ◽  
Myosin Xi

The signaling molecule auxin controls plant development through a well-known transcriptional mechanism that regulates many genes. However, auxin also triggers cellular responses within seconds or minutes, and mechanisms mediating such fast responses have remained elusive. Here, we identified an ultrafast auxin-mediated protein phosphorylation response in Arabidopsis roots that is largely independent of the canonical TIR1/AFB receptors. Among targets of this novel response are Myosin XI and its adaptor protein MadB2. We show that their auxin-mediated phosphorylation regulates trafficking and polar, subcellular distribution of PIN auxin transporters. This phosphorylation-based auxin signaling module is indispensable during developmental processes that rely on auxin-mediated PIN repolarization, such as termination of shoot gravitropic bending or vasculature formation and regeneration. Hence, we identified a fast, non-canonical auxin response targeting multiple cellular processes and revealed auxin-triggered phosphorylation of a myosin complex as the mechanism for feedback regulation of directional auxin transport, a central component of auxin canalization, which underlies self-organizing plant development.

scholarly journals HOMEOBOX PROTEIN52 Mediates the Crosstalk between Ethylene and Auxin Signaling during Primary Root Elongation by Modulating Auxin Transport-Related Gene Expression

2018 ◽  
Vol 30 (11) ◽  
pp. 2761-2778 ◽  
Author(s):  
Zi-Qing Miao ◽  
Ping-Xia Zhao ◽  
Jie-Li Mao ◽  
Lin-Hui Yu ◽  
Yang Yuan ◽  
...  
Keyword(s):  
Gene Expression ◽  
Root Elongation ◽  
Auxin Transport ◽  
Primary Root ◽  
Auxin Signaling ◽  
Related Gene

scholarly journals Enhanced polar auxin transport in tomato polycotyledon mutant seems to be related to glutathione levels

2019 ◽  
Author(s):  
Sapana Nongmaithem ◽  
Rachana Ponukumatla ◽  
Yellamaraju Sreelakshmi ◽  
Pierre Frasse ◽  
Mondher Bouzayen ◽  
...  
Keyword(s):  
Microarray Analysis ◽  
Auxin Transport ◽  
Buthionine Sulfoximine ◽  
Polar Auxin Transport ◽  
Glutathione Metabolism ◽  
Root Tips ◽  
Short Root ◽  
Hydroxyphenylacetic Acid ◽  
Naphthylphthalamic Acid

AbstractGlutathione-dependent root growth in Arabidopsis is linked to polar auxin transport (PAT). Arabidopsis mutants with reduced glutathione (GSH) levels also show reduced PAT. To gain an insight into the relationship between PAT and GSH level, we analysed tomato polycotyledon mutant, pct1-2, which has enhanced PAT. Microarray analysis of gene expression in pct1-2 mutant revealed underexpression of several genes related to glutamate and glutathione metabolism. In consonance with microarray analysis, enzymatic as well as in-vivo assay revealed higher glutathione level in the early phase of pct1-2 seedling growth than WT. The inhibition of auxin transport by 2,3,5-triiodobenzoic acid (TIBA) reduced both GSH level and PIN1 expression in pct1-2 root tips. The reduction of in vivo GSH accumulation in pct1-2 root tips by buthionine sulfoximine (BSO) stimulated elongation of the short root of pct1-2 mutant akin to TIBA. The rescue of short root phenotype of pct1-2 mutant was restricted to TIBA and BSO. The other auxin transport inhibitors 1-N-naphthylphthalamic acid (NPA), 2-[4-(diethylamino)-2-hydroxybenzoyl] benzoic acid (BUM), 3-chloro-4-hydroxyphenylacetic acid (CHPAA), brefeldin and gravacin inhibited root elongation in both WT and pct1-2 mutant. Our results indicate a relationship between PAT and GSH level in tomato akin to Arabidopsis. Our work also highlights that TIBA rescues short root phenotype of the pct1-2 mutant by acting on a PAT component distinct from the site of action of other PAT inhibitors.

scholarly journals Arabidopsis HB52 mediates the crosstalk between ethylene and auxin signaling pathways by regulating PIN2, WAG1, and WAG2 during primary root elongation

2018 ◽  
Author(s):  
Zi-Qing Miao ◽  
Ping-Xia Zhao ◽  
Jie-Li Mao ◽  
Lin-Hui Yu ◽  
Yang Yuan ◽  
...  
Keyword(s):  
Root Growth ◽  
Signaling Pathways ◽  
Molecular Mechanism ◽  
Root Elongation ◽  
Auxin Transport ◽  
Primary Root ◽  
Auxin Signaling ◽  
Elongation Zone ◽  
Ethylene Signaling ◽  
Physiological Processes

AbstractThe gaseous hormone ethylene participates in many physiological processes of plants. It is well known that ethylene-inhibited root elongation involves basipetal auxin delivery requiring PIN2. However, the molecular mechanism how ethylene regulates PIN2 is not well understood. Here, we report that the ethylene-responsive HD-Zip gene HB52 is involved in ethylene-mediated inhibition of primary root elongation. Using biochemical and genetic analyses, we demonstrated that HB52 is ethylene-responsive and acts immediately downstream of EIN3. HB52 knock-down mutants are insensitive to ethylene in primary root elongation while the overexpression lines have dramatically shortened roots like ethylene treated plants. Moreover, HB52 upregulates PIN2, WAG1, and WAG2 by directly binding to their promoter, leading to an enhanced basipetal auxin delivery to the elongation zone and thus inhibiting root growth. Our work uncovers HB52 as an important crosstalk node between ethylene signaling and auxin transport in root elongation.

scholarly journals Melon short internode (CmSi) encodes an ERECTA-like receptor kinase regulating stem elongation through auxin signaling

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Sen Yang ◽  
Kaige Zhang ◽  
Huayu Zhu ◽  
Xiaojing Zhang ◽  
Wenkai Yan ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Auxin Transport ◽  
Stem Elongation ◽  
Polar Auxin Transport ◽  
Planting Density ◽  
Stem Length ◽  
Auxin Signaling ◽  
Receptor Kinase ◽  
Internode Elongation ◽  
Short Internode

SummaryPlant height is one of the most important agronomic traits that directly determines plant architecture, and compact or dwarf plants can allow for increased planting density and land utilization as well as increased lodging resistance and economic yield. At least four dwarf/semidwarf genes have been identified in different melon varieties, but none of them have been cloned, and little is known about the molecular mechanisms underlying internode elongation in melon. Here, we report map-based cloning and functional characterization of the first semidwarf gene short internode (Cmsi) in melon, which encodes an ERECTA-like receptor kinase regulating internode elongation. Spatial-temporal expression analyses revealed that CmSI exhibited high expression in the vascular bundle of the main stem during internode elongation. The expression level of CmSI was positively correlated with stem length in the different melon varieties examined. Ectopic expression of CmSI in Arabidopsis and cucumber suggested CmSI as a positive regulator of internode elongation in both species. Phytohormone quantitation and transcriptome analysis showed that the auxin content and the expression levels of a number of genes involved in the auxin signaling pathway were altered in the semidwarf mutant, including several well-known auxin transporters, such as members of the ABCB family and PIN-FORMED genes. A melon polar auxin transport protein CmPIN2 was identified by protein–protein interaction assay as physically interacting with CmSI to modulate auxin signaling. Thus, CmSI functions in an auxin-dependent regulatory pathway to control internode elongation in melon. Our findings revealed that the ERECTA family gene CmSI regulates stem elongation in melon through auxin signaling, which can directly affect polar auxin transport.

scholarly journals Optimized Synthesis of Layered Double Hydroxide Lactate Nanosheets and Their Biological Effects on Arabidopsis Seedlings

2021 ◽  
Author(s):  
Hongyang Wu ◽  
He Zhang ◽  
Xinyu Li ◽  
Yu Zhang ◽  
Jiankun Wang ◽  
...  
Keyword(s):  
Root Growth ◽  
Layered Double Hydroxide ◽  
Root Elongation ◽  
Auxin Transport ◽  
Plant Cells ◽  
Polar Auxin Transport ◽  
Intact Plant ◽  
Bending Test ◽  
Dna Adsorption ◽  
Double Hydroxide

Abstract Background: Layered double hydroxide lactate nanosheets (LDH-lactate-NS) are powerful carriers for delivering macro-molecules into intact plant cells. In the past few years, some studies have been carried out on DNA/RNA transformation and plant disease resistance, but little attention has been paid to these factors during LDH-lactate-NS synthesis and delamination, nor has their relationship to the DNA adsorption capacity or transformation efficiency of plant cells been considered. Results: Since the temperature during delamination alters particle sizes and zeta potentials of LDH-lactate-NS products, we compared the LDH-lactate-NS stability, DNA adsorption rate and delivery efficiency of fluorescein isothiocyanate isomer I (FITC) of them, found that the LDH-lactate-NS obtained at 25℃ has the best characters for delivering biomolecules into plant cell. To understand the potential side effects and cytotoxicity of LDH-lactate-NS to plants, we compared the root growth rate between the Arabidopsis thaliana seedlings grown in the culture medium with 1-300 μg/mL LDH-lactate-NS and equivalent raw material, Mg(lactate)2 and Al (lactate)3. Phenotypic analysis showed LDH in a range of 1-300 μg/mL can enhance the root elongation, whereas the same concentration of raw materials dramatically inhibited root elongation, suggesting the nanocrystallization has a dramatical de-toxic effect to Mg(lactate)2 and Al (lactate)3. Since enhancing of root elongation by LDH is an unexpected phenomenon, we further designed experiments to investigate influence of LDH to Arabidopsis seedlings. We further used the gravitropic bending test, qRT-PCR analysis of auxin transport proteins, non-invasive micro-test technology and liquid chromatography-mass spectrometry to investigate the auxin transport and distribution in Arabidopsis root. Results indicated that LDH-lactate-NS affect root growth by increasing the polar auxin transport.Conclusions: Optimal synthesized LDH-lactate-NS can delivery biomolecules into intact plant cells with high efficiency and low cytotoxity. The working solution of LDH-lactate-NS can promote root elongation via increase the polar auxin transport in Arabidopsis roots.

Auxin and ETTIN in Arabidopsis gynoecium morphogenesis

Development ◽  
2000 ◽  
Vol 127 (18) ◽  
pp. 3877-3888 ◽  
Author(s):  
J.L. Nemhauser ◽  
L.J. Feldman ◽  
P.C. Zambryski
Keyword(s):  
Auxin Transport ◽  
Floral Organ ◽  
Polar Auxin Transport ◽  
Auxin Response ◽  
Auxin Transport Inhibitor ◽  
Increased Sensitivity ◽  
Auxin Flux ◽  
Naphthylphthalamic Acid

The phytohormone auxin has wide-ranging effects on growth and development. Genetic and physiological approaches implicate auxin flux in determination of floral organ number and patterning. This study uses a novel technique of transiently applying a polar auxin transport inhibitor, N-1-naphthylphthalamic acid (NPA), to developing Arabidopsis flowers to further characterize the role of auxin in organogenesis. NPA has marked effects on floral organ number as well as on regional specification in wild-type gynoecia, as defined by morphological and histological landmarks for regional boundaries, as well as tissue-specific reporter lines. NPA's effects on gynoecium patterning mimic the phenotype of mutations in ETTIN, a member of the auxin response factor family of transcription factors. In addition, application of different concentrations of NPA reveal an increased sensitivity of weak ettin alleles to disruptions in polar auxin transport. In contrast, the defects found in spatula gynoecia are partially rescued by treatment with NPA. A model is proposed suggesting an apical-basal gradient of auxin during gynoecium development. This model provides a mechanism linking ETTIN's putative transcriptional regulation of auxin-responsive genes to the establishment or elaboration of tissue patterning during gynoecial development.

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