RACK1A positively regulates opening of the apical hook in via suppression of its auxin response gradient.

Apical hook development is an ideal model for studying differential growth in plants and is controlled by complex phytohormonal crosstalk, with auxin being the major player. Here, we identified a bioactive small molecule that decelerates apical hook opening in . Our genetic studies suggest that this molecule enhances or maintains the auxin maximum found in the inner hook side and requires certain auxin signaling components to modulate apical hook opening.

Efficient, cell-type-specific production of flavonols by multiplexed CRISPR activation of a suite of metabolic enzymes.

Synthetic biology in plants promises to transform basic and applied research by rewiring entire developmental modules, signaling cascades or metabolic pathways. Yet, this requires expression of many genes simultaneously, very difficult with classic transgenic approaches, especially for the generation of stable traits. CRISPR activation systems work in plants and could greatly facilitate multiplexed gene activation.

Core biological principles and tools stemming from basic Arabidopsis research.

The model plant Arabidopsis thaliana has been a cornerstone of research in plant biology, contributing transformative insights into fundamental biological processes across eukaryotes. In this vignette, we explore the role of Arabidopsis in elucidating immune mechanisms, where plant studies have informed mammalian immunity and translational regulation. We discuss how Arabidopsis-driven advancements in pangenomics and repeat expansions have reshaped our understanding of genomic variability and its implications for diseases like Friedreich's ataxia.

Active transport enables protein condensation in cells.

Multiple factors drive biomolecular condensate formation. In plants, condensation of the transcription factors AUXIN RESPONSE FACTOR 7 (ARF7) and ARF19 attenuates response to the plant hormone auxin. Here, we report that actin-mediated movement of cytoplasmic ARF condensates enhances condensation.

Protocol for determining regulators of competence in regeneration of adventitious roots using hypocotyl wounding approach in Arabidopsis.

Plant plasticity enables the regeneration of adventitious roots upon wounding. Here, we present a protocol for inducing adventitious roots in wounded Arabidopsis hypocotyls, phenotyping, and spatiotemporal gene expression analysis. We also describe the steps for quantifying early adventitious root developmental stages.

Hierarchy in regulator interactions with distant transcriptional activation domains empowers rheostatic regulation.

Transcription factors carry long intrinsically disordered regions often containing multiple activation domains. Despite numerous recent high-throughput identifications and characterizations of activation domains, the interplay between sequence motifs, activation domains, and regulator binding in intrinsically disordered transcription factor regions remains unresolved. Here, we map sequence motifs and activation domains in an Arabidopsis thaliana NAC transcription factor clade, revealing that although sequence motifs and activation domains often coincide, no systematic overlap exists.

Comparative mutant analyses reveal a novel mechanism of ARF regulation in land plants.

The plant hormone auxin regulates a wide variety of transcriptional responses depending on the cell type, environment and species. How this diversity is achieved may be related to the specific complement of auxin-signalling components in each cell. The levels of activators (class-A AUXIN RESPONSE FACTORS) and repressors (class-B ARFs) are particularly important.

An improved toolkit of gateway- and gibson assembly-compatible vectors for protoplast transfection and agrobacterium-mediated plant transformation.

Objective: Understanding the regulation and function of plant genes is essential for addressing the challenges faced by modern agriculture. Plant transformation, in conjunction with fluorescence microscopy, offers a powerful approach to investigate the dynamic behavior of plant genes and the proteins they encode. We previously developed a set of Gateway-compatible tissue-specific plant transformation vectors.

Allovalent scavenging of activation domains in the transcription factor ANAC013 gears transcriptional regulation.

Transcriptional regulation involves interactions between transcription factors, coregulators, and DNA. Intrinsic disorder is a major player in this regulation, but mechanisms driven by disorder remain elusive. Here, we address molecular communication within the stress-regulating Arabidopsis thaliana transcription factor ANAC013.

Apical hook opening of plant seedlings: Unfolding the role of auxin and the cell wall.

Apical hook opening is crucial for seedling establishment and is regulated by unequal distribution of the hormone auxin through unknown mechanisms. In this issue of Developmental Cell, Walia et al. demonstrate that apical hook opening is an output of tissue-wide forces; auxin and cell wall integrity (CWI) signaling interact to restrict elongation to the concave side of the apical hook.

Advancing our understanding of root development: Technologies and insights from diverse studies.

Understanding root development is critical for enhancing plant growth and health, and advanced technologies are essential for unraveling the complexities of these processes. In this review, we highlight select technological innovations in the study of root development, with a focus on the transformative impact of single-cell gene expression analysis. We provide a high-level overview of recent advancements, illustrating how single-cell RNA sequencing (scRNA-seq) has become a pivotal tool in plant biology.

Factors governing cellular reprogramming competence in Arabidopsis adventitious root formation.

Developmental reprogramming allows for flexibility in growth and adaptation to changing environmental conditions. In plants, wounding events can result in new stem cell niches and lateral organs. Adventitious roots develop from aerial parts of the plant and are regulated by multiple stimuli, including wounding.

Hierarchical global and local auxin signals coordinate cellular interdigitation in .

The development of multicellular tissues requires both local and global coordination of cell polarization, however, the mechanisms underlying their interplay are poorly understood. In Arabidopsis, leaf epidermal pavement cells (PC) develop a puzzle-piece shape locally coordinated through apoplastic auxin signaling. Here we show auxin also globally coordinates interdigitation by activating the TIR1/AFB-dependent nuclear signaling pathway.

ZmPILS6 is an auxin efflux carrier required for maize root morphogenesis.

Plant root systems play a pivotal role in plant physiology and exhibit diverse phenotypic traits. Understanding the genetic mechanisms governing root growth and development in model plants like maize is crucial for enhancing crop resilience to drought and nutrient limitations. This study focused on identifying and characterizing ZmPILS6, an annotated auxin efflux carrier, as a key regulator of various crown root traits in maize.

An auxin research odyssey: 1989-2023.

The phytohormone auxin is at times called the master regulator of plant processes and has been shown to be a central player in embryo development, the establishment of the polar axis, early aspects of seedling growth, as well as growth and organ formation during later stages of plant development. The Plant Cell has been key, since the inception of the journal, to developing an understanding of auxin biology. Auxin-regulated plant growth control is accomplished by both changes in the levels of active hormones and the sensitivity of plant tissues to these concentration changes.

Defying gravity: WEEP promotes negative gravitropism in peach trees by establishing asymmetric auxin gradients.

Trees with weeping shoot architectures are valued for their beauty and are a resource for understanding how plants regulate posture control. The peach (Prunus persica) weeping phenotype, which has elliptical downward arching branches, is caused by a homozygous mutation in the WEEP gene. Little is known about the function of WEEP despite its high conservation throughout Plantae.

Molecular switching in transcription through splicing and proline-isomerization regulates stress responses in plants.

The Arabidopsis thaliana DREB2A transcription factor interacts with the negative regulator RCD1 and the ACID domain of subunit 25 of the transcriptional co-regulator mediator (Med25) to integrate stress signals for gene expression, with elusive molecular interplay. Using biophysical and structural analyses together with high-throughput screening, we reveal a bivalent binding switch in DREB2A containing an ACID-binding motif (ABS) and the known RCD1-binding motif (RIM). The RIM is lacking in a stress-induced DREB2A splice variant with retained transcriptional activity.

Abscisic acid biosynthesis is necessary for full auxin effects on hypocotyl elongation.

In concert with other phytohormones, auxin regulates plant growth and development. However, how auxin and other phytohormones coordinately regulate distinct processes is not fully understood. In this work, we uncover an auxin-abscisic acid (ABA) interaction module in Arabidopsis that is specific to coordinating activities of these hormones in the hypocotyl.

Auxin and abiotic stress responses.

Plants are exposed to a variety of abiotic stresses; these stresses have profound effects on plant growth, survival, and productivity. Tolerance and adaptation to stress require sophisticated stress sensing, signaling, and various regulatory mechanisms. The plant hormone auxin is a key regulator of plant growth and development, playing pivotal roles in the integration of abiotic stress signals and control of downstream stress responses.

AUXIN RESPONSE FACTOR protein accumulation and function.

Auxin is a key regulator of plant developmental processes. Its effects on transcription are mediated by the AUXIN RESPONSE FACTOR (ARF) family of transcription factors. ARFs tightly control specific auxin responses necessary for proper plant growth and development.

Defying Gravity: promotes negative gravitropism in (peach) shoots and roots by establishing asymmetric auxin gradients.

Trees with weeping shoot architectures are valued for their beauty and serve as tremendous resources for understanding how plants regulate posture control. The (peach) weeping phenotype, which has elliptical downward arching branches, is caused by a homozygous mutation in the gene. Until now, little was known about the function of WEEP protein despite its high conservation throughout Plantae.

Nitric oxide-mediated S-nitrosylation of IAA17 protein in intrinsically disordered region represses auxin signaling.

The phytohormone auxin plays crucial roles in nearly every aspect of plant growth and development. Auxin signaling is activated through the phytohormone-induced proteasomal degradation of the Auxin/INDOLE-3-ACETIC ACID (Aux/IAA) family of transcriptional repressors. Notably, many auxin-modulated physiological processes are also regulated by nitric oxide (NO) that executes its biological effects predominantly through protein S-nitrosylation at specific cysteine residues.