The role of pre-symbiotic auxin signaling in ectendomycorrhiza formation between the desert truffle Terfezia boudieri and Helianthemum sessiliflorum

Light cues from neighboring vegetation rapidly initiate plant shade-avoidance responses. Despite our detailed knowledge of the early steps of this response, the molecular events under prolonged shade are largely unclear. Here we show that persistent neighbor cues reinforce growth responses in addition to promoting auxin-responsive gene expression in Arabidopsis and soybean. However, while the elevation of auxin levels is well established as an early event, in Arabidopsis, the response to prolonged shade occurs when auxin levels have declined to the prestimulation values. Remarkably, the sustained low activity of phytochrome B under prolonged shade led to (i) decreased levels of PHYTOCHROME INTERACTING FACTOR 4 (PIF4) in the cotyledons (the organs that supply auxin) along with increased levels in the vascular tissues of the stem, (ii) elevated expression of the PIF4 targets INDOLE-3-ACETIC ACID 19 (IAA19) and IAA29, which in turn reduced the expression of the growth-repressive IAA17 regulator, (iii) reduced abundance of AUXIN RESPONSE FACTOR 6, (iv) reduced expression of MIR393 and increased abundance of its targets, the auxin receptors, and (v) elevated auxin signaling as indicated by molecular markers. Mathematical and genetic analyses support the physiological role of this system-level rearrangement. We propose that prolonged shade rewires the connectivity between light and auxin signaling to sustain shade avoidance without enhanced auxin levels.

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The Role of MiRNAs in Auxin Signaling and Regulation During Plant Development

Plant Epigenetics - RNA Technologies ◽

10.1007/978-3-319-55520-1_2 ◽

2017 ◽

pp. 23-48 ◽

Cited By ~ 1

Author(s):

Clelia De-la-Peña ◽

Geovanny I. Nic-Can ◽

Johny Avilez-Montalvo ◽

José E. Cetz-Chel ◽

Víctor M. Loyola-Vargas

Keyword(s):

Plant Development ◽

Auxin Signaling

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Improved Sensory Quality and Antioxidant Capacity of Wheat Bread Supplemented with the Desert Truffle Terfezia boudieri Flour

Analytical Letters ◽

10.1080/00032719.2020.1786106 ◽

2020 ◽

pp. 1-17

Author(s):

H. Najjaa ◽

Radhia Abdelkbir ◽

A. Ben Arfa ◽

E. Doria ◽

H. Tlili ◽

...

Keyword(s):

Antioxidant Capacity ◽

Sensory Quality ◽

Wheat Bread ◽

Desert Truffle ◽

Terfezia Boudieri

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Nutraceutical potential, antioxidant and antibacterial activities of Terfezia boudieri Chatin, a wild edible desert truffle from Tunisia arid zone

Arabian Journal of Chemistry ◽

10.1016/j.arabjc.2013.06.015 ◽

2016 ◽

Vol 9 (3) ◽

pp. 383-389 ◽

Cited By ~ 17

Author(s):

Amina Hamza ◽

Nacim Zouari ◽

Sami Zouari ◽

Hamida Jdir ◽

Slah Zaidi ◽

...

Keyword(s):

Arid Zone ◽

Antibacterial Activities ◽

Desert Truffle ◽

Terfezia Boudieri

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YUCCAauxin biosynthetic genes are required for Arabidopsis shade avoidance

PeerJ ◽

10.7717/peerj.2574 ◽

2016 ◽

Vol 4 ◽

pp. e2574 ◽

Cited By ~ 29

Author(s):

Patricia Müller-Moulé ◽

Kazunari Nozue ◽

Melissa L. Pytlak ◽

Christine M. Palmer ◽

Michael F. Covington ◽

...

Keyword(s):

Light Treatment ◽

Auxin Signaling ◽

Shade Avoidance ◽

Biosynthetic Genes ◽

Petiole Elongation ◽

Quadruple Mutant ◽

Avoidance Responses

Plants respond to neighbor shade by increasing stem and petiole elongation. Shade, sensed by phytochrome photoreceptors, causes stabilization ofPHYTOCHROME INTERACTING FACTORproteins and subsequent induction ofYUCCAauxin biosynthetic genes. To investigate the role ofYUCCAgenes in phytochrome-mediated elongation, we examined auxin signaling kinetics after an end-of-day far-red (EOD-FR) light treatment, and found that an auxin responsive reporter is rapidly induced within 2 hours of far-red exposure.YUCCA2, 5, 8,and9are all induced with similar kinetics suggesting that theycould act redundantly to control shade-mediated elongation. To test this hypothesis we constructed ayucca2, 5, 8, 9quadruple mutant and found that the hypocotyl and petiole EOD-FR and shade avoidance responses are completely disrupted. This work shows thatYUCCAauxin biosynthetic genes are essential for detectable shade avoidance and thatYUCCAgenes are important for petiole shade avoidance.

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A synthetic approach reveals a highly sensitive maize auxin response circuit

10.1101/844100 ◽

2019 ◽

Author(s):

Román Ramos Báez ◽

Yuli Buckley ◽

Han Yu ◽

Zongliang Chen ◽

Andrea Gallavotti ◽

...

Keyword(s):

Auxin Signaling ◽

Synthetic Approach ◽

Auxin Response ◽

Auxin Receptor ◽

Repressor Proteins ◽

Highly Sensitive ◽

Signaling Function ◽

Wide Range ◽

Signaling Components

Auxin plays a key role across all land plants in growth and developmental processes. Although auxin signaling function has diverged and expanded, differences in the molecular functions of signaling components have largely been characterized in Arabidopsis thaliana. Here, we used the Auxin Response Circuit recapitulated in Saccharomyces cerevisiae (ARCSc) system to functionally annotate maize auxin signaling components, focusing on genes expressed during development of ear and tassel inflorescences. All 16 maize Auxin (Aux)/Indole-3-Acetic Acid (IAA) repressor proteins are degraded in response to auxin, with rates that depended on both receptor and repressor identity. When fused to the maize TOPLESS (TPL) homolog RAMOSA1 ENHANCER LOCUS2 (REL2), maize Aux/IAAs were able to repress AUXIN RESPONSE FACTOR (ARF) transcriptional activity. A complete auxin response circuit comprised of all maize components, including ZmAFB2/3 b1 maize AUXIN SIGNALING F-BOX (AFB) receptor, was found to be fully functional. The ZmAFB2/3 b1 auxin receptor was found to be more sensitive to hormone than AtAFB2 and allowed for rapid circuit activation upon auxin addition. These results validate the conserved role of predicted auxin response genes in maize, as well as provide evidence that a synthetic approach can facilitate broader comparative studies across the wide range of species with sequenced genomes.

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Pharmacological and genetic manipulations of Ca2+ signaling have contrasting effects on auxin-regulated trafficking

10.1101/2020.09.04.283101 ◽

2020 ◽

Author(s):

Ren Wang ◽

Ellie Himschoot ◽

Matteo Grenzi ◽

Jian Chen ◽

Melanie Krebs ◽

...

Keyword(s):

Developmental Plasticity ◽

Brefeldin A ◽

Inhibitory Effect ◽

Auxin Signaling ◽

Polar Localization ◽

Genetic Manipulations ◽

The One ◽

Molecular Components ◽

Regulated Trafficking

ABSTRACTA large part of a plants’ developmental plasticity relies on the activities of the phytohormone auxin and the regulation of its own distribution. This process involves a cohort of transcriptional and non-transcriptional effects of auxin on polar auxin transport, regulating the abundancy, biochemical activity and polar localization of the molecular components, predominantly PIN auxin exporters. While the transcriptional auxin signaling cascade has been well characterized, the mechanism and role of non-transcriptional auxin signaling remains largely elusive. Here, we addressed the potential involvement of auxin-induced Ca2+ signaling in auxin’s inhibitory effect on PIN endocytic trafficking. On the one hand, exogenous manipulations of Ca2+ availability and signaling effectively antagonized auxin effects suggesting that auxin-induced Ca2+ signaling is required for inhibition of internalization. On the other hand, we addressed the auxin-mediated inhibition of PIN internalization in the auxin signaling (tir1afb2,3) or Ca2+ channel (cngc14) mutants. These mutants were strongly defective in auxin-triggered Ca2+ signaling, but not in auxin-inhibited internalization. These data imply that, while Ca2+ signaling may be required for normal PIN trafficking, auxin-mediated increase in Ca2+ signaling is not a direct part of a downstream mechanism that mediates auxin effects on Brefeldin A-visualized PIN intercellular aggregation. These contrasting results obtained by comparing the mutant analysis versus the exogenous manipulations of Ca2+ availability and signaling illustrate the critical importance of genetics to unravel the role of Ca2+ in a process of interest.

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An auxin signaling network translates low-sugar-state input into compensated cell enlargement in the fugu5 cotyledon

PLoS Genetics ◽

10.1371/journal.pgen.1009674 ◽

2021 ◽

Vol 17 (8) ◽

pp. e1009674

Author(s):

Hiromitsu Tabeta ◽

Shunsuke Watanabe ◽

Keita Fukuda ◽

Shizuka Gunji ◽

Mariko Asaoka ◽

...

Keyword(s):

Atpase Activity ◽

Molecular Mechanisms ◽

Genetic Interaction ◽

Mitotic Cell ◽

Fine Tuning ◽

Auxin Signaling ◽

Cell Enlargement ◽

Loss Of Function ◽

Nutrient Reserves

In plants, the effective mobilization of seed nutrient reserves is crucial during germination and for seedling establishment. The Arabidopsis H+-PPase-loss-of-function fugu5 mutants exhibit a reduced number of cells in the cotyledons. This leads to enhanced post-mitotic cell expansion, also known as compensated cell enlargement (CCE). While decreased cell numbers have been ascribed to reduced gluconeogenesis from triacylglycerol, the molecular mechanisms underlying CCE remain ill-known. Given the role of indole 3-butyric acid (IBA) in cotyledon development, and because CCE in fugu5 is specifically and completely cancelled by ech2, which shows defective IBA-to-indoleacetic acid (IAA) conversion, IBA has emerged as a potential regulator of CCE. Here, to further illuminate the regulatory role of IBA in CCE, we used a series of high-order mutants that harbored a specific defect in IBA-to-IAA conversion, IBA efflux, IAA signaling, or vacuolar type H+-ATPase (V-ATPase) activity and analyzed the genetic interaction with fugu5–1. We found that while CCE in fugu5 was promoted by IBA, defects in IBA-to-IAA conversion, IAA response, or the V-ATPase activity alone cancelled CCE. Consistently, endogenous IAA in fugu5 reached a level 2.2-fold higher than the WT in 1-week-old seedlings. Finally, the above findings were validated in icl–2, mls–2, pck1–2 and ibr10 mutants, in which CCE was triggered by low sugar contents. This provides a scenario in which following seed germination, the low-sugar-state triggers IAA synthesis, leading to CCE through the activation of the V-ATPase. These findings illustrate how fine-tuning cell and organ size regulation depend on interplays between metabolism and IAA levels in plants.

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Expression and Role of Biosynthetic, Transporter, Receptor, and Responsive Genes for Auxin Signaling during Clubroot Disease Development

International Journal of Molecular Sciences ◽

10.3390/ijms21155554 ◽

2020 ◽

Vol 21 (15) ◽

pp. 5554

Author(s):

Arif Hasan Khan Robin ◽

Gopal Saha ◽

Rawnak Laila ◽

Jong-In Park ◽

Hoy-Taek Kim ◽

...

Keyword(s):

Plasmodiophora Brassicae ◽

Fold Increase ◽

Auxin Signaling ◽

Post Inoculation ◽

Disease Development ◽

Secondary Phases ◽

Auxin Receptor ◽

Clubroot Disease ◽

Root Tissues

Auxins play a pivotal role in clubroot development caused by the obligate biotroph Plasmodiophora brassicae. In this study, we investigated the pattern of expression of 23 genes related to auxin biosynthesis, reception, and transport in Chinese cabbage (Brassica rapa) after inoculation with P. brassicae. The predicted proteins identified, based on the 23 selected auxin-related genes, were from protein kinase, receptor kinase, auxin responsive, auxin efflux carrier, transcriptional regulator, and the auxin-repressed protein family. These proteins differed in amino acids residue, molecular weights, isoelectric points, chromosomal location, and subcellular localization. Leaf and root tissues showed dynamic and organ-specific variation in expression of auxin-related genes. The BrGH3.3 gene, involved in auxin signaling, exhibited 84.4-fold increase in expression in root tissues compared to leaf tissues as an average of all samples. This gene accounted for 4.8-, 2.6-, and 5.1-fold higher expression at 3, 14, and 28 days post inoculation (dpi) in the inoculated root tissues compared to mock-treated roots. BrNIT1, an auxin signaling gene, and BrPIN1, an auxin transporter, were remarkably induced during both cortex infection at 14 dpi and gall formation at 28 dpi. BrDCK1, an auxin receptor, was upregulated during cortex infection at 14 dpi. The BrLAX1 gene, associated with root hair development, was induced at 1 dpi in infected roots, indicating its importance in primary infection. More interestingly, a significantly higher expression of BrARP1, an auxin-repressed gene, at both the primary and secondary phases of infection indicated a dynamic response of the host plant towards its resistance against P. brassicae. The results of this study improve our current understanding of the role of auxin-related genes in clubroot disease development.

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