Regulation of polar auxin transport in grapevine fruitlets (Vitis vinifera L.) and the proposed role of auxin homeostasis during fruit abscission

Asymmetric auxin distribution is instrumental for the differential growth that causes organ bending on tropic stimuli and curvatures during plant development. Local differences in auxin concentrations are achieved mainly by polarized cellular distribution of PIN auxin transporters, but whether other mechanisms involving auxin homeostasis are also relevant for the formation of auxin gradients is not clear. Here we show that auxin methylation is required for asymmetric auxin distribution across the hypocotyl, particularly during its response to gravity. We found that loss-of-function mutants inArabidopsis IAA CARBOXYL METHYLTRANSFERASE1(IAMT1) prematurely unfold the apical hook, and that their hypocotyls are impaired in gravitropic reorientation. This defect is linked to an auxin-dependent increase inPINgene expression, leading to an increased polar auxin transport and lack of asymmetric distribution of PIN3 in theiamt1mutant. Gravitropic reorientation in theiamt1mutant could be restored with either endodermis-specific expression ofIAMT1or partial inhibition of polar auxin transport, which also results in normalPINgene expression levels. We propose that IAA methylation is necessary in gravity-sensing cells to restrict polar auxin transport within the range of auxin levels that allow for differential responses.

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Role of auxin homeostasis and response in nitrogen limitation and dark stimulation of adventitious root formation in petunia cuttings

Annals of Botany ◽

10.1093/aob/mcz095 ◽

2019 ◽

Vol 124 (6) ◽

pp. 1053-1066 ◽

Cited By ~ 7

Author(s):

Huaiyu Yang ◽

Yvonne Klopotek ◽

Mohammad R Hajirezaei ◽

Siegfried Zerche ◽

Philipp Franken ◽

...

Keyword(s):

Nitrogen Limitation ◽

Auxin Transport ◽

Polar Auxin Transport ◽

Auxin Homeostasis ◽

Stem Base ◽

Auxin Signalling ◽

Dark Exposure ◽

Rna Accumulation ◽

Low Nitrogen ◽

Stimulation Of

Abstract Background and Aims Adventitious root (AR) formation in Petunia hybrida is inhibited by low nitrogen fertilization of stock plants but promoted by dark incubation of cuttings before planting. We investigated whether the plant hormone auxin is involved in nitrogen- and dark-mediated AR formation. Methods Concentrations of indole-3-acetic acid (IAA) and RNA accumulation of genes controlling auxin homeostasis and function were monitored in the stem base in response to high versus low nitrogen supply to stock plants and to temporal dark vs. light exposure of cuttings by use of GC-MS/MS, a petunia-specific microarray and quantitative RT-PCR. Auxin source capacity, polar auxin transport in cuttings and auxin concentration in the rooting zone were manipulated to investigate the functional contribution of auxin homeostasis and response to the effects of nitrogen fertilization and dark exposure on rooting. Key Results The nitrogen content of cuttings had only a marginal effect on IAA concentration in the stem base. Dark incubation enhanced the accumulation of IAA in the stem base during AR induction independent of nitrogen level. Early IAA accumulation in the dark depended on the upper shoot as an auxin source and was enhanced after apical IAA supply. Dark exposure stimulated RNA accumulation of auxin-related genes. In particular, expression of Ph-PIN1 and of genes controlling auxin signalling, including Ph-IAA14, Ph-ARF8, Ph-ARF10 and Ph-SAUR14, was enhanced, while the latter four were repressed in nitrogen-limited cuttings, particularly in the dark. Dark stimulation of rooting depended on polar auxin transport. Basal auxin application partially substituted the effect of dark exposure on rooting, whereas the auxin response of AR formation was strongly depressed by nitrogen limitation. Conclusions Increased auxin delivery from the upper shoot and enhanced auxin signalling in the stem base contribute to dark-stimulated AR formation, while nitrogen limitation inhibits AR formation downstream of the auxin signal.

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The role of polar auxin transport through pedicels of Prunus avium L. in relation to fruit development and retention

Journal of Experimental Botany ◽

10.1093/jxb/erh208 ◽

2004 ◽

Vol 55 (405) ◽

pp. 2099-2109 ◽

Cited By ~ 38

Author(s):

M. A. Else

Keyword(s):

Fruit Development ◽

Auxin Transport ◽

Prunus Avium ◽

Polar Auxin Transport ◽

Prunus Avium L

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Ethylene Does Not Promote Adventitious Root Initiation on Apple Microcuttings

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.121.5.880 ◽

1996 ◽

Vol 121 (5) ◽

pp. 880-885 ◽

Cited By ~ 7

Author(s):

James F. Harbage ◽

Dennis P. Stimart

Keyword(s):

Carboxylic Acid ◽

Auxin Transport ◽

Adventitious Rooting ◽

Polar Auxin Transport ◽

Root Initiation ◽

Ethylene Evolution ◽

Basal Section ◽

Naphthylphthalamic Acid ◽

Transport Inhibitors

We investigated the role of ethylene on adventitious rooting of `Gala' (easy-to-root) and `Triple Red Delicious' (difficult-to-root) apple (Malus domestica Borkh.) microcuttings. Root count increased significantly as IBA level increased, with highest root counts on `Gala'. Ethylene evolution increased significantly with IBA level without significant differences between cultivars. Basal section removal of microcuttings in the area of root origin reduced root count without changing ethylene evolution. Ethylene treatment of proliferated shoots before microcutting excision failed to enhance rooting. IBA-induced ethylene evolution was eliminated nearly by AVG, but root count remained IBA dependent. ACC reversed IBA plus AVG rooting inhibition, but ACC alone failed to influence root count. Polar auxin transport inhibitors NPA and TIBA stimulated ethylene evolution without increasing root count. Adventitious rooting of apple microcuttings was not associated with ethylene. Chemical names used: 1-H-indole-3-butyric acid (IBA); aminoethoxyvinylglycine (AVG); 1-aminocyclopropane-1-carboxylic acid (ACC); 2,3,5-triiodobenzoic acid (TIBA); N-1-naphthylphthalamic acid (NPA).

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Possible neuromodulating role of different grape (Vitis vinifera L.) derived polyphenols against Alzheimer’s dementia: treatment and mechanisms

Bulletin of the National Research Centre ◽

10.1186/s42269-019-0149-z ◽

2019 ◽

Vol 43 (1) ◽

Cited By ~ 3

Author(s):

Ghadha Ibrahim Fouad ◽

Maha Zaki Rizk

Keyword(s):

Vitis Vinifera ◽

Alzheimer’S Dementia ◽

Vitis Vinifera L ◽

Alzheimer's Dementia ◽

Dementia Treatment

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(Z)-3-Hexenyl Butyrate Induces Stomata Closure and Ripening in Vitis vinifera

Agronomy ◽

10.3390/agronomy10081122 ◽

2020 ◽

Vol 10 (8) ◽

pp. 1122

Author(s):

Celia Payá ◽

M. Pilar López-Gresa ◽

Diego S. Intrigliolo ◽

Ismael Rodrigo ◽

José María Bellés ◽

...

Keyword(s):

Vitis Vinifera ◽

Field Experiments ◽

Negative Impact ◽

Block Design ◽

Stomatal Closure ◽

Total Yield ◽

Soluble Solids ◽

Vitis Vinifera L ◽

Randomized Block Design

Agronomy solutions for modifying pre-harvest grape ripening are needed for a more sustainable viticulture. Field experiments were performed in Vitis vinifera L. vines to study the effect of the previously described stomata-closing compound (Z)-3-hexenyl butyrate (HB). Exogenous treatments at different doses were periodically carried out using a randomized block design. Firstly, we observed that HB was able to induce stomatal closure in grapevine plants. Under field conditions, the application of HB around veraison induced a higher color intensity in berries, and vines treated at higher doses reached this stage earlier than the un-treated controls. There was also a clear increase in both grape anthocyanin concentration and total soluble solids without having a negative impact on total yield. We therefore, confirm the role of HB as a universal natural stomatal closure compound and propose a new use for HB in viticulture as a ripening inducer, by accelerating anthocyanin accumulation.

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