Found: The missing discriminators of cell-surface auxin receptors.

An Arabidopsis cell-surface auxin receptor that mediates rapid elongation consists of transmembrane kinases (TMKs) and an auxin-binding co-receptor. Auxin-binding protein 1 (ABP1) is one identified TMK co-receptor, but abp1 mutants have no elongation phenotypes. Yu et al.

Mother trees, altruistic fungi, and the perils of plant personification.

There are growing doubts about the true role of the common mycorrhizal networks (CMN or wood wide web) connecting the roots of trees in forests. We question the claims of a substantial carbon transfer from 'mother trees' to their offspring and nearby seedlings through the CMN. Recent reviews show that evidence for the 'mother tree concept' is inconclusive or absent.

Gibberellins promote polar auxin transport to regulate stem cell fate decisions in cambium.

Vascular cambium contains bifacial stem cells, which produce secondary xylem to one side and secondary phloem to the other. However, how these fate decisions are regulated is unknown. Here we show that the positioning of an auxin signalling maximum within the cambium determines the fate of stem cell daughters.

Loss of Multiple ABCB Auxin Transporters Recapitulates the Major Phenotypes in .

FK506-BINDING PROTEIN 42/TWISTED DWARF 1 (FKBP42/TWD1) directly regulates cellular trafficking and activation of multiple ATP-BINDING CASSETTE (ABC) transporters from the ABCB and ABCC subfamilies. double mutants exhibit remarkable phenotypic overlap with including severe dwarfism, stamen elongation defects, and compact circinate leaves; however, mutants exhibit greater loss of polar auxin transport and additional helical twisting of roots, inflorescences, and siliques. As mutants do not exhibit any visible phenotypes and TWD1 does not interact with PIN or AUX1/LAX auxin transporters, loss of function of other ABCB auxin transporters is hypothesized to underly the remaining morphological phenotypes.

Auxin Transporters-A Biochemical View.

From embryogenesis to fruit formation, almost every aspect of plant development and differentiation is controlled by the cellular accumulation or depletion of auxin from cells and tissues. The respective auxin maxima and minima are generated by cell-to-cell auxin transport via transporter proteins. Differential auxin accumulation as a result of such transport processes dynamically regulates auxin distribution during differentiation.

High-resolution mapping of the Mov-1 locus in wheat by combining radiation hybrid (RH) and recombination-based mapping approaches.

This work reports a quick method that integrates RH mapping and genetic mapping to map the dominant Mov-1 locus to a 1.1-Mb physical interval with a small number of candidate genes. Bread wheat is an important crop for global human population.

The Potassium Transporter OsHAK5 Alters Rice Architecture via ATP-Dependent Transmembrane Auxin Fluxes.

Plant HAK/KUP/KT family members function as plasma membrane (PM) H/K symporters and may modulate chemiosmotically-driven polar auxin transport (PAT). Here, we show that inactivation of , a rice K transporter gene, decreased rootward and shootward PAT, tiller number, and the length of both lateral roots and root hairs, while overexpression increased PAT, tiller number, and root hair length, irrespective of the K supply. Inhibitors of ATP-binding-cassette type-B transporters, NPA and BUM, abolished the -overexpression effect on PAT.

An ATP-Binding Cassette Transporter, ABCB19, Regulates Leaf Position and Morphology during Phototropin1-Mediated Blue Light Responses.

Blue light regulates multiple processes that optimize light capture and gas exchange in plants, including chloroplast movement, changes in stomatal conductance, and altered organ positioning. In Arabidopsis (), these processes are primarily modulated by the blue light phototropin photoreceptors phot1 and phot2. Changes in leaf positioning and shape involve several signaling components that include NON-PHOTOTROPIC HYPOCOTYL3, PHYTOCHROME KINASE SUBSTRATE, ROOT PHOTOTROPISM2, and alterations in localized auxin streams.

Corrigendum: The Arabidopsis ATP-BINDING CASSETTE Transporter ABCB21 Regulates Auxin Levels in Cotyledons, the Root Pericycle, and Leaves.

[This corrects the article DOI: 10.3389/fpls.2019.

Seasonal nitrogen remobilization and the role of auxin transport in poplar trees.

Seasonal nitrogen (N) cycling in Populus, involves bark storage proteins (BSPs) that accumulate in bark phloem parenchyma in the autumn and decline when shoot growth resumes in the spring. Little is known about the contribution of BSPs to growth or the signals regulating N remobilization from BSPs. Knockdown of BSP accumulation via RNAi and N sink manipulations were used to understand how BSP storage influences shoot growth.

Auxin regulates adventitious root formation in tomato cuttings.

Background: Adventitious root (AR) formation is a critical developmental process in cutting propagation for the horticultural industry. While auxin has been shown to regulate this process, the exact mechanism and details preceding AR formation remain unclear. Even though AR and lateral root (LR) formation share common developmental processes, there are exist some differences that need to be closely examined at the cytological level.

Plants Neither Possess nor Require Consciousness.

In claiming that plants have consciousness, 'plant neurobiologists' have consistently glossed over the remarkable degree of structural and functional complexity that the brain had to evolve for consciousness to emerge. Here, we outline a new hypothesis proposed by Feinberg and Mallat for the evolution of consciousness in animals. Based on a survey of the brain anatomy, functional complexity, and behaviors of a broad spectrum of animals, criteria were established for the emergence of consciousness.

The Arabidopsis ATP-BINDING CASSETTE Transporter ABCB21 Regulates Auxin Levels in Cotyledons, the Root Pericycle, and Leaves.

The phytohormone auxin plays significant roles in regulating plant growth and development. In Arabidopsis, a subset of ATP-BINDING CASSETTE subfamily B (ABCB) transporters participate in polar movement of auxin by exclusion from and prevention of reuptake at the plasma membrane. A previous analysis identified ABCB21 as a conditional auxin uptake/efflux transporter that regulates cellular auxin levels, but clear physiological roles for ABCB21 remain unknown.

Elevated auxin and reduced cytokinin contents in rootstocks improve their performance and grafting success.

Plant grafting is an important technique for horticultural and silvicultural production. However, many rootstock plants suffer from undesirable lateral bud outgrowth, low grafting success rates or poor rooting. Here, we used a root-predominant gene promoter (SbUGT) to drive the expression of a tryptophan-2-monooxygenase gene (iaaM) from Agrobacterium tumefaciens to increase auxin levels in tobacco.

An Arabidopsis ABC Transporter Mediates Phosphate Deficiency-Induced Remodeling of Root Architecture by Modulating Iron Homeostasis in Roots.

The remodeling of root architecture is a major developmental response of plants to phosphate (Pi) deficiency and is thought to enhance a plant's ability to forage for the available Pi in topsoil. The underlying mechanism controlling this response, however, is poorly understood. In this study, we identified an Arabidopsis mutant, hps10 (hypersensitive to Pi starvation 10), which is morphologically normal under Pi sufficient condition but shows increased inhibition of primary root growth and enhanced production of lateral roots under Pi deficiency.

Directed plant cell-wall accumulation of iron: embedding co-catalyst for efficient biomass conversion.

Background: Plant lignocellulosic biomass is an abundant, renewable feedstock for the production of biobased fuels and chemicals. Previously, we showed that iron can act as a co-catalyst to improve the deconstruction of lignocellulosic biomass. However, directly adding iron catalysts into biomass prior to pretreatment is diffusion limited, and increases the cost of biorefinery operations.

Cell wall targeted in planta iron accumulation enhances biomass conversion and seed iron concentration in Arabidopsis and rice.

Conversion of nongrain biomass into liquid fuel is a sustainable approach to energy demands as global population increases. Previously, we showed that iron can act as a catalyst to enhance the degradation of lignocellulosic biomass for biofuel production. However, direct addition of iron catalysts to biomass pretreatment is diffusion-limited, would increase the cost and complexity of biorefinery unit operations and may have deleterious environmental impacts.

Microscopic and Biochemical Visualization of Auxins in Plant Tissues.

Auxins are a particularly notable class of phytohormones in that they regulate plant growth and development at sites of synthesis, and via a regulated polar transport system comprising PIN, ABCB, and AUX/LAX transport proteins. In order to fully understand auxin-regulated physiological processes, it is therefore essential to be able to determine where indole-3-acetic acid and related compounds are being synthesized, where they are transported to, and how much IAA is accumulating in any given tissue. Auxin may be visualized either indirectly, through the use of auxin responsive promoters; directly, through the use of radiolabelled auxin or fluorescent auxin analogs; or biochemically through extraction and mass-spectrometric quantification of auxin and auxin metabolites from target cells or tissues.