-
Annual Review of Plant Biology Apr 2016Light is crucial for plant life, and perception of the light environment dictates plant growth, morphology, and developmental changes. Such adjustments in growth and... (Review)
Review
Light is crucial for plant life, and perception of the light environment dictates plant growth, morphology, and developmental changes. Such adjustments in growth and development in response to light conditions are often established through changes in hormone levels and signaling. This review discusses examples of light-regulated processes throughout a plant's life cycle for which it is known how light signals lead to hormonal regulation. Light acts as an important developmental switch in germination, photomorphogenesis, and transition to flowering, and light cues are essential to ensure light capture through architectural changes during phototropism and the shade avoidance response. In describing well-established links between light perception and hormonal changes, we aim to give insight into the mechanisms that enable plants to thrive in variable light environments.
Topics: Flowers; Germination; Light; Photosynthesis; Phototrophic Processes; Phototropism; Plant Development; Plant Growth Regulators; Plants; Signal Transduction
PubMed: 26905653
DOI: 10.1146/annurev-arplant-043015-112252 -
Plant & Cell Physiology Mar 2015Plants depend on the surrounding light environment to direct their growth. Blue light (300-500 nm) in particular acts to promote a wide variety of photomorphogenic... (Review)
Review
Plants depend on the surrounding light environment to direct their growth. Blue light (300-500 nm) in particular acts to promote a wide variety of photomorphogenic responses including seedling establishment, phototropism and circadian clock regulation. Several different classes of flavin-based photoreceptors have been identified that mediate the effects of blue light in the dicotyledonous genetic model Arabidopsis thaliana. These include the cryptochromes, the phototropins and members of the Zeitlupe family. In this review, we discuss recent advances, which contribute to our understanding of how these photosensory systems are activated by blue light and how they initiate signaling to regulate diverse aspects of plant development.
Topics: Cryptochromes; Flavoproteins; Models, Biological; Photoreceptors, Plant; Phototropins; Signal Transduction
PubMed: 25516569
DOI: 10.1093/pcp/pcu196 -
The New Phytologist Sep 2021Characterising the processes that control auxin dynamics is essential to understanding how auxin regulates plant development. Over recent years, several studies have... (Review)
Review
Characterising the processes that control auxin dynamics is essential to understanding how auxin regulates plant development. Over recent years, several studies have investigated auxin diffusion through plasmodesmata, characterising this cell-to-cell diffusion and demonstrating that it affects auxin distributions. Furthermore, studies have shown that plasmodesmatal auxin diffusion affects developmental processes, including phototropism, lateral root emergence and leaf hyponasty. This short Tansley Insight review describes how these studies have contributed to our understanding of auxin dynamics and discusses potential future directions in this area.
Topics: Gene Expression Regulation, Plant; Indoleacetic Acids; Phototropism; Plant Development; Plant Roots; Plasmodesmata
PubMed: 34053083
DOI: 10.1111/nph.17517 -
Current Biology : CB May 2015Plants are photoautotrophic sessile organisms that use environmental cues to optimize multiple facets of growth and development. A classic example is phototropism - in... (Review)
Review
Plants are photoautotrophic sessile organisms that use environmental cues to optimize multiple facets of growth and development. A classic example is phototropism - in shoots this is typically positive, leading to growth towards the light, while roots frequently show negative phototropism triggering growth away from the light. Shoot phototropism optimizes light capture of leaves in low light environments and hence increases photosynthetic productivity. Phototropins are plasma-membrane-associated UV-A/blue-light activated kinases that trigger phototropic growth. Light perception liberates their protein kinase domain from the inhibitory action of the amino-terminal photosensory portion of the photoreceptor. Following a series of still poorly understood events, phototropin activation leads to the formation of a gradient of the growth hormone auxin across the photo-stimulated stem. The greater auxin concentration on the shaded compared with the lit side of the stem enables growth reorientation towards the light. In this Minireview, we briefly summarize the signaling steps starting from photoreceptor activation until the establishment of a lateral auxin gradient, ultimately leading to phototropic growth in shoots.
Topics: Arabidopsis; Indoleacetic Acids; Phototropins; Phototropism; Plant Development; Ultraviolet Rays
PubMed: 25942556
DOI: 10.1016/j.cub.2015.03.020 -
Physiologia Plantarum Jul 2020Positive phototropism is the process through which plants orient their organs toward a directional light source. While the blue light receptors phototropins (phot) play... (Review)
Review
Positive phototropism is the process through which plants orient their organs toward a directional light source. While the blue light receptors phototropins (phot) play a major role in phototropism toward blue (B) and ultraviolet (UV) radiation, recent research showed that the UVB light receptor UVR8 also triggers phototropism toward UVB. In addition, new details of the molecular mechanisms underlying the activity of these receptors and interaction with other environmental signals have emerged in the past years. In this review, we summarize the current knowledge about hypocotyledoneous and inflorescence stem growth reorientation toward B and UVB, with a focus on the molecular mechanisms.
Topics: Arabidopsis; Arabidopsis Proteins; Chromosomal Proteins, Non-Histone; Light; Phototropins; Phototropism; Ultraviolet Rays
PubMed: 32208516
DOI: 10.1111/ppl.13098 -
Plant & Cell Physiology Sep 2021The disruption of the sumoylation pathway affects processes controlled by the two phototropins (phots) of Arabidopsis thaliana, phot1 and phot2. Phots, plant UVA/blue...
The disruption of the sumoylation pathway affects processes controlled by the two phototropins (phots) of Arabidopsis thaliana, phot1 and phot2. Phots, plant UVA/blue light photoreceptors, regulate growth responses and fast movements aimed at optimizing photosynthesis, such as phototropism, chloroplast relocations and stomatal opening. Sumoylation is a posttranslational modification, consisting of the addition of a SUMO (SMALL UBIQUITIN-RELATED MODIFIER) protein to a lysine residue in the target protein. In addition to affecting the stability of proteins, it regulates their activity, interactions and subcellular localization. We examined physiological responses controlled by phots, phototropism and chloroplast movements, in sumoylation pathway mutants. Chloroplast accumulation in response to both continuous and pulse light was enhanced in the E3 ligase siz1 mutant, in a manner dependent on phot2. A significant decrease in phot2 protein abundance was observed in this mutant after blue light treatment both in seedlings and mature leaves. Using plant transient expression and yeast two-hybrid assays, we found that phots interacted with SUMO proteins mainly through their N-terminal parts, which contain the photosensory LOV domains. The covalent modification in phots by SUMO was verified using an Arabidopsis sumoylation system reconstituted in bacteria followed by the mass spectrometry analysis. Lys 297 was identified as the main target of SUMO3 in the phot2 molecule. Finally, sumoylation of phot2 was detected in Arabidopsis mature leaves upon light or heat stress treatment.
Topics: Arabidopsis; Arabidopsis Proteins; Chloroplasts; Escherichia coli; Ligases; Lysine; Mutation; Phototropism; Plant Leaves; Plants, Genetically Modified; Protein Serine-Threonine Kinases; Seedlings; Small Ubiquitin-Related Modifier Proteins; Sumoylation
PubMed: 33594440
DOI: 10.1093/pcp/pcab027 -
Current Opinion in Plant Biology Feb 2018While fast plant movements are spectacular but rare, almost all plants exhibit relatively slow, growth-mediated tropic movements that are key to their survival in the... (Review)
Review
While fast plant movements are spectacular but rare, almost all plants exhibit relatively slow, growth-mediated tropic movements that are key to their survival in the natural world. In this brief review, we discuss recent insights into the molecular mechanisms underlying phototropism, gravitropism, hydrotropism, and autostraightening. Careful molecular genetic and physiological studies have helped confirm the importance of lateral auxin gradients in gravitropic and phototropic responses. However, auxin signaling does not explain all tropisms: recent work has shown that abscisic acid signaling mediates root hydrotropism and has implicated mechanosensing in autostraightening, the organ straightening process recently modeled as a proprioceptive response. The interactions between distinct tropic signaling pathways and other internal and external sensory processes are also now being untangled.
Topics: Gravitropism; Light; Phototropism; Plant Development; Plant Physiological Phenomena; Plant Roots; Plants; Signal Transduction; Tropism
PubMed: 29107827
DOI: 10.1016/j.pbi.2017.10.003 -
Frontiers in Bioengineering and... 2017Biohybrid consists of a living organism or cell and at least one engineered component. Designing robot-plant biohybrids is a great challenge: it requires... (Review)
Review
Biohybrid consists of a living organism or cell and at least one engineered component. Designing robot-plant biohybrids is a great challenge: it requires interdisciplinary reconsideration of capabilities intimate specific to the biology of plants. Envisioned advances should improve agricultural/horticultural/social practice and could open new directions in utilization of plants by humans. Proper biohybrid cooperation depends upon effective communication. During evolution, plants developed many ways to communicate with each other, with animals, and with microorganisms. The most notable examples are: the use of phytohormones, rapid long-distance signaling, gravity, and light perception. These processes can now be intentionally re-shaped to establish plant-robot communication. In this article, we focus on plants physiological and molecular processes that could be used in bio-hybrids. We show phototropism and biomechanics as promising ways of effective communication, resulting in an alteration in plant architecture, and discuss the specifics of plants anatomy, physiology and development with regards to the bio-hybrids. Moreover, we discuss ways how robots could influence plants growth and development and present aims, ideas, and realized projects of plant-robot biohybrids.
PubMed: 28856135
DOI: 10.3389/fbioe.2017.00046 -
Biochemistry. Biokhimiia Jun 2018A variety of living organisms including bacteria, fungi, animals, and plants use blue light (BL) to adapt to changing ambient light. Photosynthetic forms (plants and... (Review)
Review
A variety of living organisms including bacteria, fungi, animals, and plants use blue light (BL) to adapt to changing ambient light. Photosynthetic forms (plants and algae) require energy of light for photosynthesis, movements, development, and regulation of activity. Several complex light-sensitive systems evolved in eukaryotic cells to use the information of light efficiently with photoreceptors selectively absorbing various segments of the solar spectrum, being the first components in the light signal transduction chain. They are most diverse in algae. Photosynthetic stramenopiles, which received chloroplasts from red algae during secondary symbiosis, play an important role in ecosystems and aquaculture, being primary producers. These taxa acquired the ability to use BL for regulation of such processes as phototropism, chloroplast photo-relocation movement, and photomorphogenesis. A new type of BL receptor - aureochrome (AUREO) - was identified in Vaucheria frigida in 2007. AUREO consists of two domains: bZIP (basic-region leucine zipper) domain and LOV (light-oxygen-voltage-sensing) domain, and thus this photoreceptor is a BL-sensitive transcription factor. This review presents current data on the structure, mechanisms of action, and biochemical features of aureochromes.
Topics: Fungi; Light; Optogenetics; Photoreceptors, Microbial; Photoreceptors, Plant; Photosynthesis; Plants; Signal Transduction
PubMed: 30195323
DOI: 10.1134/S0006297918060044 -
The Plant Journal : For Cell and... Apr 2023Directional movements impact the ability of plants to respond and adjust their growth accordingly to the prevailing light environment. The plasma-membrane associated...
Directional movements impact the ability of plants to respond and adjust their growth accordingly to the prevailing light environment. The plasma-membrane associated protein, ROOT PHOTOTROPISM 2 (RPT2) is a key signalling component involved in chloroplast accumulation movement, leaf positioning, and phototropism, all of which are regulated redundantly by the ultraviolet/blue light-activated AGC kinases phototropin 1 and 2 (phot1 and phot2). We recently demonstrated that members of the NON-PHOTOTROPIC HYPOCOTYL 3 (NPH3)/RPT2-like (NRL) family in Arabidopsis thaliana, including RPT2, are directly phosphorylated by phot1. However, whether RPT2 is a substrate for phot2, and the biological significance of phot phosphorylation of RPT2 remains to be determined. Here, we show that RPT2 is phosphorylated by both phot1 and phot2 at a conserved serine residue (S591) within the C-terminal region of the protein. Blue light triggered the association of 14-3-3 proteins with RPT2 consistent with S591 acting as a 14-3-3 binding site. Mutation of S591 had no effect on the plasma membrane localization of RPT2 but reduced its functionality for leaf positioning and phototropism. Moreover, our findings indicate that S591 phosphorylation within the C-terminus of RPT2 is required for chloroplast accumulation movement to low level blue light. Taken together, these findings further highlight the importance of the C-terminal region of NRL proteins and how its phosphorylation contributes to phot receptor signalling in plants.
Topics: Arabidopsis; Phototropism; Phosphorylation; Phototropins; Arabidopsis Proteins; Protein Serine-Threonine Kinases; Plants, Genetically Modified; Light; Plant Leaves; Chloroplasts; Phosphoproteins
PubMed: 36794876
DOI: 10.1111/tpj.16144