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1.
Development ; 149(4)2022 02 15.
Article in English | MEDLINE | ID: mdl-35029672

ABSTRACT

The submergence-induced hypoxic condition negatively affects the plant growth and development, and causes early onset of senescence. Hypoxia alters the expression of a number of microRNAs (miRNAs). However, the molecular function of submergence stress-induced miRNAs in physiological or developmental changes and recovery remains poorly understood. Here, we show that miR775 is an Arabidopsis thaliana-specific young and unique miRNA that possibly evolved non-canonically. miR775 post-transcriptionally regulates GALACTOSYLTRANSFERASE 9 (GALT9) and their expression is inversely affected at 24 h of complete submergence stress. The overexpression of miR775 (miR775-Oe) confers enhanced recovery from submergence stress and reduced accumulation of RBOHD and ROS, in contrast to wild-type and MIM775 Arabidopsis shoot. A similar recovery phenotype in the galt9 mutant indicates the role of the miR775-GALT9 module in post-submergence recovery. We predicted that Golgi-localized GALT9 is potentially involved in protein glycosylation. The altered expression of senescence-associated genes (SAG12, SAG29 and ORE1), ethylene signalling (EIN2 and EIN3) and abscisic acid (ABA) biosynthesis (NCED3) pathway genes occurs in miR775-Oe, galt9 and MIM775 plants. Thus, our results indicate the role for the miR775-GALT9 module in post-submergence recovery through a crosstalk between the ethylene signalling and ABA biosynthesis pathways.


Subject(s)
Arabidopsis Proteins/metabolism , Arabidopsis/metabolism , Ethylenes/pharmacology , Galactosyltransferases/metabolism , MicroRNAs/metabolism , Plant Senescence/drug effects , Abscisic Acid/metabolism , Arabidopsis/genetics , Arabidopsis/growth & development , Arabidopsis Proteins/chemistry , Arabidopsis Proteins/genetics , Binding Sites , Cysteine Endopeptidases/genetics , Cysteine Endopeptidases/metabolism , Dioxygenases/genetics , Dioxygenases/metabolism , Galactosyltransferases/genetics , Golgi Apparatus/metabolism , MicroRNAs/chemistry , MicroRNAs/genetics , NADPH Oxidases/genetics , NADPH Oxidases/metabolism , Plant Leaves/genetics , Plant Leaves/metabolism , Plant Proteins/genetics , Plant Proteins/metabolism , Plants, Genetically Modified/genetics , Plants, Genetically Modified/growth & development , Plants, Genetically Modified/metabolism , Reactive Oxygen Species/metabolism , Receptors, Cell Surface/genetics , Receptors, Cell Surface/metabolism , Signal Transduction/genetics , Stress, Physiological
2.
Development ; 148(1)2021 01 05.
Article in English | MEDLINE | ID: mdl-33168582

ABSTRACT

Root system architecture and anatomy of monocotyledonous maize is significantly different from dicotyledonous model Arabidopsis The molecular role of non-coding RNA (ncRNA) is poorly understood in maize root development. Here, we address the role of LEAFBLADELESS1 (LBL1), a component of maize trans-acting short-interfering RNA (ta-siRNA), in maize root development. We report that root growth, anatomical patterning, and the number of lateral roots (LRs), monocot-specific crown roots (CRs) and seminal roots (SRs) are significantly affected in lbl1-rgd1 mutant, which is defective in production of ta-siRNA, including tasiR-ARF that targets AUXIN RESPONSE FACTOR3 (ARF3) in maize. Altered accumulation and distribution of auxin, due to differential expression of auxin biosynthesis and transporter genes, created an imbalance in auxin signalling. Altered expression of microRNA165/166 (miR165/166) and its targets, ROLLED1 and ROLLED2 (RLD1/2), contributed to the changes in lbl1-rgd1 root growth and vascular patterning, as was evident by the altered root phenotype of Rld1-O semi-dominant mutant. Thus, LBL1/ta-siRNA module regulates root development, possibly by affecting auxin distribution and signalling, in crosstalk with miR165/166-RLD1/2 module. We further show that ZmLBL1 and its Arabidopsis homologue AtSGS3 proteins are functionally conserved.


Subject(s)
Conserved Sequence , MicroRNAs/metabolism , Plant Proteins/metabolism , Plant Roots/embryology , Plant Roots/genetics , RNA, Small Interfering/metabolism , Arabidopsis/genetics , Biosynthetic Pathways , Body Patterning/genetics , Cell Count , Cell Division , Gene Expression Regulation, Plant , Genes, Plant , Indoleacetic Acids/metabolism , MicroRNAs/genetics , Models, Biological , Mutation/genetics , Organ Specificity/genetics , Phenotype , Plant Proteins/genetics , Plant Vascular Bundle/embryology , Plant Vascular Bundle/genetics , Up-Regulation/genetics , Zea mays
3.
Physiol Plant ; 175(4): e13968, 2023.
Article in English | MEDLINE | ID: mdl-37402164

ABSTRACT

Serotonin is a well-studied pineal hormone that functions as a neurotransmitter in mammals and is found in varying amounts in diverse plant species. By modulating gene and phytohormonal crosstalk, serotonin has a significant role in plant growth and stress response, including root, shoot, flowering, morphogenesis, and adaptability responses to numerous environmental signals. Despite its prevalence and importance in plant growth and development, its molecular action, regulation and signalling processes remain unknown. Here, we highlight the current knowledge of the role of serotonin-mediated regulation of plant growth and stress response. We focus on serotonin and its regulatory connections with phytohormonal crosstalk and address their possible functions in coordinating diverse phytohormonal responses during distinct developmental phases, correlating with melatonin. Additionally, we have also discussed the possible role of microRNAs (miRNAs) in the regulation of serotonin biosynthesis. In summary, serotonin may act as a node molecule to coordinate the balance between plant growth and stress response, which may shed light on finding its key regulatory pathways for uncovering its mysterious molecular network.


Subject(s)
Melatonin , Serotonin , Serotonin/metabolism , Plant Development , Plant Growth Regulators/metabolism , Plants/genetics , Plants/metabolism , Gene Expression Regulation, Plant
4.
Physiol Plant ; 174(4): e13736, 2022 Jul.
Article in English | MEDLINE | ID: mdl-35716004

ABSTRACT

Deepwater is an abiotic stress that limits rice cultivation worldwide due to recurrent floods. The miRNAs and lncRNAs are two non-coding RNAs emerging as major regulators of gene expressions under different abiotic stresses. However, the regulation of these two non-coding RNAs under deepwater stress in rice is still unexplored. In this study, small RNA-seq and RNA-seq from internode and node tissues were analyzed to predict deepwater stress responsive miRNAs and lncRNAs, respectively. Additionally, a competitive endogenous RNA (ceRNA) study revealed about 69 and 25 lncRNAs acting as endogenous target mimics (eTM) with the internode and node miRNAs, respectively. In ceRNA analyses, some of the key miRNAs such as miR1850.1, miR1848, and IN-nov-miR145 were upregulated while miR159e was downregulated, and their respective eTM lncRNAs and targets were found to have opposite expressions. Moreover, we have transiently expressed one module (IN-nov-miR145-Cc-TCONS_00011544-Os11g36430.3) in tobacco leaves. The integrated analysis has identified differentially expressed (DE) miRNAs, lncRNAs and their target genes, and the complex regulatory network, which might lead to stem elongation under deepwater stress. In this novel attempt to identify and characterize miRNAs and lncRNAs under deepwater stress in rice, we have provided, probably for the first time, a reference platform to study the interactions of these two non-coding RNAs with respective target genes through transient expression analyses.


Subject(s)
MicroRNAs , Oryza , RNA, Long Noncoding , Gene Regulatory Networks , MicroRNAs/genetics , MicroRNAs/metabolism , Oryza/metabolism , RNA, Long Noncoding/genetics , RNA, Messenger/metabolism , Stress, Physiological/genetics
5.
Semin Cell Dev Biol ; 96: 91-99, 2019 12.
Article in English | MEDLINE | ID: mdl-31075379

ABSTRACT

Crop productivity in rice is harshly limited due to high concentration of salt in the soil. To understand the intricacies of the mechanism it is important to unravel the key pathways operating inside the plant cell. Emerging state-of-the art technologies have provided the tools to discover the key components inside the plant cell for salt tolerance. Among the molecular entities, transcription factors and/or other important components of sensing and signaling cascades have been the attractive targets and the role of NHX and SOS1 transporters amply described. Not only marker assisted programs but also transgenic approaches by using reverse genetic strategies (knockout or knockdown) or overexpression have been extensively used to engineer rice crop. CRISPR/Cas is an attractive paradigm and provides the feasibility for manipulating several genes simultaneously. Here, in this review we highlight some of the molecular entities that could be potentially targeted for generating rice amenable to sustain growth under high salinity conditions by employing CRISPR/Cas. We also try to address key questions for rice salt stress tolerance other than what is already known.


Subject(s)
CRISPR-Cas Systems/genetics , Gene Editing , Oryza/genetics , Salt Stress/genetics
6.
Plant J ; 101(1): 87-100, 2020 01.
Article in English | MEDLINE | ID: mdl-31483536

ABSTRACT

Auxin signaling mediated by various auxin/indole-3-acetic acid (Aux/IAAs) and AUXIN RESPONSE FACTORs (ARFs) regulate lateral root (LR) development by controlling the expression of downstream genes. LATERAL ROOT PRIMORDIUM1 (LRP1), a member of the SHORT INTERNODES/STYLISH (SHI/STY) family, was identified as an auxin-inducible gene. The precise developmental role and molecular regulation of LRP1 in root development remain to be understood. Here we show that LRP1 is expressed in all stages of LR development, besides the primary root. The expression of LRP1 is regulated by histone deacetylation in an auxin-dependent manner. Our genetic interaction studies showed that LRP1 acts downstream of auxin responsive Aux/IAAs-ARFs modules during LR development. We showed that auxin-mediated induction of LRP1 is lost in emerging LRs of slr-1 and arf7arf19 mutants roots. NPA treatment studies showed that LRP1 acts after LR founder cell specification and asymmetric division during LR development. Overexpression of LRP1 (LRP1 OE) showed an increased number of LR primordia (LRP) at stages I, IV and V, resulting in reduced emerged LR density, which suggests that it is involved in LRP development. Interestingly, LRP1-induced expression of YUC4, which is involved in auxin biosynthesis, contributes to the increased accumulation of endogenous auxin in LRP1 OE roots. LRP1 interacts with SHI, STY1, SRS3, SRS6 and SRS7 proteins of the SHI/STY family, indicating their possible redundant role during root development. Our results suggested that auxin and histone deacetylation affect LRP1 expression and it acts downstream of LR forming auxin response modules to negatively regulate LRP development by modulating auxin homeostasis in Arabidopsis thaliana.


Subject(s)
Arabidopsis Proteins/metabolism , Arabidopsis/growth & development , Arabidopsis/metabolism , Indoleacetic Acids/metabolism , Arabidopsis/genetics , Arabidopsis Proteins/genetics , Epigenesis, Genetic/genetics , Epigenesis, Genetic/physiology , Gene Expression Regulation, Plant/genetics , Gene Expression Regulation, Plant/physiology , Mutation/genetics , Plant Roots/genetics , Plant Roots/growth & development , Plant Roots/metabolism , Signal Transduction/genetics , Signal Transduction/physiology
7.
Plant Physiol ; 180(2): 998-1012, 2019 06.
Article in English | MEDLINE | ID: mdl-30971449

ABSTRACT

Gibberellic Acid Stimulated Transcript (GAST)-like genes encode small polypeptides, some of which have been implicated in diverse biological processes regulating plant growth and development. However, the occurrence of GASTs among plants, their protein structures, and the mechanisms by which they evolved remain elusive. Here, using a customized workflow, we report genes encoding GAST proteins, identify novel motifs and evolutionary patterns contributing to the subfunctionalization of GAST domains, and explore functional conservation across diverse plant groups. We show that GAST-like sequences evolved initially in the vascular plant Selaginella moellendorffii, after the divergence from bryophytes, and later emerged in gymnosperms and angiosperms. GASTs in angiosperms are characterized by four conserved novel motifs; however, relatively fewer conserved motifs exist in pteridophytes and gymnosperms. Phylogenetic analysis revealed that the GAST-Cysteine Rich1 motif evolved early in the S. moellendorffii GAST, which further acquired subfunctionalization through successive conjugation of other motifs and remained conserved across plants, as supported by their collinearity. Functional characterization of two orthologs from the dicot Arabidopsis (Arabidopsis thaliana; Gibberellic Acid-Stimulated Arabidopsis 10) and the monocot rice (Oryza sativa; Gibberellic Acid Stimulated Transcript-Related 9) suggests hormonal regulation, novel roles in seed germination, and functional conservation among diverse plant groups. Computational modeling predicts that these GAST genes are regulated by several factors, including the phytohormones gibberellin and abscisic acid, through conserved cis-motifs present in their promoters, and that they might act as signaling molecules in a complex feedback loop. Thus, our study identifies GASTs and their encoded proteins, uncovers their structure, novel motifs, and evolutionary pattern among plants, and suggests their functional conservation.


Subject(s)
Evolution, Molecular , Gibberellins/metabolism , Plant Proteins/chemistry , Plant Proteins/metabolism , Amino Acid Motifs , Amino Acid Sequence , Arabidopsis/genetics , Arabidopsis/metabolism , Bryophyta/metabolism , Conserved Sequence , Cysteine/metabolism , Gene Expression Regulation, Plant , Gene Regulatory Networks , Germination , Models, Molecular , Oryza/genetics , Oryza/metabolism , Phenotype , Phylogeny , Plant Proteins/genetics , Protein Domains , RNA, Messenger/genetics , RNA, Messenger/metabolism , Seeds/growth & development , Sequence Homology, Amino Acid , Tracheophyta/metabolism
8.
J Exp Bot ; 71(3): 778-792, 2020 01 23.
Article in English | MEDLINE | ID: mdl-31793642

ABSTRACT

In higher plants, pluripotent stem cells reside in the specialized microenvironment called stem cell niches (SCNs) harbored at the shoot apical meristem (SAM) and root apical meristem (RAM), which give rise to the aerial and underground parts of a plant, respectively. The model plant Arabidopsis thaliana (Arabidopsis) has been extensively studied to decipher the intricate regulatory mechanisms involving some key transcriptions factors and phytohormones that play pivotal roles in stem cell homeostasis, meristem maintenance, and organ formation. However, there is increasing evidence to show the epigenetic regulation of the chromatin architecture, gene expression exerting an influence on an innate balance between the self-renewal of stem cells, and differentiation of the progeny cells to a specific tissue type or organ. Post-translational histone modifications, ATP-dependent chromatin remodeling, and chromatin assembly/disassembly are some of the key features involved in the modulation of chromatin architecture. Here, we discuss the major epigenetic regulators and illustrate their roles in the regulation of stem cell activity, meristem maintenance, and related organ patterning in Arabidopsis.


Subject(s)
Arabidopsis/growth & development , Chromatin Assembly and Disassembly , Meristem/physiology , Stem Cell Niche/physiology , Arabidopsis Proteins/metabolism , Gene Regulatory Networks , Homeodomain Proteins/metabolism , Plant Proteins/metabolism
9.
BMC Evol Biol ; 19(1): 55, 2019 02 14.
Article in English | MEDLINE | ID: mdl-30764768

ABSTRACT

BACKGROUND: Micro RNAs (miRNAs), a class of small non-coding RNAs, have been implicated in various aspects of plant development. miR394 is required for shoot apical meristem organization, stem cell maintenance and abiotic stress responses in Arabidopsis, where it functions by negatively regulating the transcript level of target LEAF CURLING RESPONSIVENESS (LCR), which is an F-box protein-coding gene. The evolutionary conservation of stem cell regulatory miR394-LCR module among plants remains elusive. RESULTS: Our study has identified 79 miR394 and 43 target sequences across 40 plant species using various homology based search tools and databases, and analysed their co-evolution pattern. We customised an annotation workflow which computationally validates 20 novel miR394s from 14 plant species. Independent phylogenetic trees were reconstructed with precursor MIR394s, mature miR394s, and their target sequences along with complementary miR394 binding sites. The phylogeny revealed that mature sequences of miR394s as well as their targets belonging to the F-box protein encoding gene families, were highly conserved. Though, miR394-3p were complementary to miR394s/miR394-5p, they clustered separately. CONCLUSION: The existence and separate clustering of miR394-3p and miR394s/miR394-5p indicate their independent regulation. The phylogeny also suggests that miR394s had evolved at the beginning of gymnosperm-angiosperm divergence. Despite strong conservation, some level of sequence variation in miR394s and the complementary binding sites of their targets suggests possible functional diversification of miR394-LCR mediated stem cell regulation in plants.


Subject(s)
Evolution, Molecular , MicroRNAs/genetics , Plants/genetics , RNA, Plant/genetics , Arabidopsis/genetics , Base Sequence , Conserved Sequence/genetics , Gene Expression Regulation, Plant , Genome, Plant , MicroRNAs/metabolism , Molecular Sequence Annotation , Multigene Family , Phylogeny , RNA Precursors/genetics , RNA Precursors/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , RNA, Plant/metabolism , Species Specificity , Stress, Physiological/genetics
10.
BMC Genomics ; 20(1): 596, 2019 Jul 20.
Article in English | MEDLINE | ID: mdl-31325959

ABSTRACT

BACKGROUND: Root morphology is known to be affected by light quality, quantity and direction. Light signal is perceived at the shoot, translocated to roots through vasculature and further modulates the root development. Photoreceptors are differentially expressed in both shoot and root cells. The light irradiation to the root affects shoot morphology as well as whole plant development. The current work aims to understand the white light intensity dependent changes in root patterning and correlate that with the global gene expression profile. RESULTS: Different fluence of white light (WL) regulate overall root development via modulating the expression of a specific set of genes. Phytochrome A deficient Arabidopsis thaliana (phyA-211) showed shorter primary root compared to phytochrome B deficient (phyB-9) and wild type (WT) seedlings at a lower light intensity. However, at higher intensity, both mutants showed shorter primary root in comparison to WT. The lateral root number was observed to be lowest in phyA-211 at intensities of 38 and 75 µmol m - 2 s - 1. The number of adventitious roots was significantly lower in phyA-211 as compared to WT and phyB-9 under all light intensities tested. With the root phenotypic data, microarray was performed for four different intensities of WL light in WT. Here, we identified ~ 5243 differentially expressed genes (DEGs) under all light intensities. Gene ontology-based analysis indicated that different intensities of WL predominantly affect a subset of genes having catalytic activity and localized to the cytoplasm and membrane. Furthermore, when root is irradiated with different intensities of WL, several key genes involved in hormone, light signaling and clock-regulated pathways are differentially expressed. CONCLUSION: Using genome wide microarray-based approach, we have identified candidate genes in Arabidopsis root that responded to the changes in light intensities. Alteration in expression of genes such as PIF4, COL9, EPR1, CIP1, ARF18, ARR6, SAUR9, TOC1 etc. which are involved in light, hormone and clock pathway was validated by qRT-PCR. This indicates their potential role in light intensity mediated root development.


Subject(s)
Arabidopsis/genetics , Arabidopsis/radiation effects , Light , Plant Roots/growth & development , Plant Roots/radiation effects , Arabidopsis/cytology , Arabidopsis/growth & development , Biological Clocks/genetics , Biological Clocks/radiation effects , Dose-Response Relationship, Radiation , Gene Ontology , Mutation , Phytochrome A/genetics , Signal Transduction/genetics , Signal Transduction/radiation effects , Time Factors , Transcriptome/radiation effects
11.
Planta ; 249(6): 2015-2020, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30976910

ABSTRACT

MAIN CONCLUSION: Isolation of high-quality RNA, including miRNA, from microscopic woody apple bud meristem using laser capture microdissection-based method. It is often challenging to study the expression of microRNAs (miRNAs) or genes in less accessible inner tissues of tree species rich in polyphenols or polysaccharides. Here, we report a laser capture microdissection (LCM)-based method for efficient and cost-effective isolation and expression analysis of miRNAs and genes in the meristem tissue of woody apple bud. The tissue fixation, processing, infiltration, and sectioning steps were optimized for LCM-based excision and subsequent RNA isolation. Further, we have confirmed that RNA isolated from LCM-derived apple bud meristem contained miRNAs and was of good quantity and quality, sufficient for downstream expression analysis.


Subject(s)
Laser Capture Microdissection , Malus/genetics , MicroRNAs/genetics , Gene Expression Profiling , Malus/ultrastructure , Meristem/genetics , Meristem/ultrastructure , RNA, Plant/genetics , Tissue Fixation , Wood
12.
Planta ; 248(3): 545-558, 2018 Sep.
Article in English | MEDLINE | ID: mdl-29968061

ABSTRACT

MAIN CONCLUSION: Present review addresses the advances made in the understanding of biogenesis of plant small RNAs and their role in plant development. We discuss the elaborate role of microRNAs (miRNAs) and trans-acting small interfering RNAs (ta-siRNAs) in various aspects of plant growth and development and highlight relevance of small RNA mobility. Small non-coding RNAs regulate various aspects of plant development. Small RNAs (sRNAs) of 21-24 nucleotide length are derived from double-stranded RNAs through the combined activity of several biogenesis and processing components. These sRNAs function by negatively regulating the expression of target genes. miRNAs and ta-siRNAs constitute two important classes of endogenous small RNAs in plants, which play important roles in plant growth and developmental processes like embryogenesis, organ formation and patterning, shoot and root growth, and reproductive development. Biogenesis of miRNAs is a multistep process which includes transcription, processing and modification, and their loading onto RNA-induced silencing complex (RISC). RISC-loaded miRNAs carry out post-transcriptional silencing of their target(s). Recent studies identified orthologues of different biogenesis components of novel and conserved small RNAs from different model plants. Although many small RNAs have been identified from diverse plant species, only a handful of them have been functionally characterized. In this review, we discuss the advances made in understanding the biogenesis, functional conservation/divergence in miRNA-mediated gene regulation, and the developmental role of small RNAs in different plant species.


Subject(s)
Plant Development , RNA, Plant/metabolism , RNA, Small Untranslated/metabolism , Flowers/growth & development , Gene Expression Regulation, Plant , Germination , Meristem/growth & development , Plant Development/genetics , Plant Leaves/growth & development , Plant Roots/growth & development , Plant Shoots/growth & development , Plants/genetics , Plants/metabolism , Seeds/growth & development
13.
Plant Cell Physiol ; 56(6): 1107-23, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25759329

ABSTRACT

Phosphate (Pi) is pivotal for plant growth and development. Pi deficiency triggers local and systemically regulated adaptive responses in Arabidopsis thaliana. Inhibition of primary root growth (PRG) and retarded development of lateral roots (LRs) are typical local Pi deficiency-mediated responses of the root system. Expression of Pi starvation-responsive (PSR) genes is regulated systemically. Here, we report the differential influence of iron (Fe) availability on local and systemic sensing of Pi by Arabidopsis. P-Fe- condition disrupted local Pi sensing, resulting in an elongated primary root (PR). Altered Fe homeostasis in the lpsi mutant with aberration in local Pi sensing provided circumstantial evidence towards the role of Fe in the maintenance of Pi homeostasis. Reporter gene assays, expression analysis of auxin-responsive genes (ARGs) and root phenotyping of the arf7arf19 mutant demonstrated the role of Fe availability on local Pi deficiency-mediated LR development. In addition, Fe availability also exerted a significant influence on PSR genes belonging to different functional categories. Together, these results demonstrated a substantial influence of Fe availability on Pi deficiency-mediated responses of ontogenetically distinct traits of the root system and PSR genes. The study also provided evidence of cross-talk between Pi, Fe and Zn, highlighting a complex tripartite interaction amongst them for maintaining Pi homeostasis.


Subject(s)
Arabidopsis/metabolism , Indoleacetic Acids/metabolism , Iron/metabolism , Phosphates/deficiency , Zinc/metabolism , Arabidopsis/drug effects , Arabidopsis/genetics , Arabidopsis/growth & development , Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolism , Gene Expression Regulation, Plant/drug effects , Genes, Plant , Homeostasis/drug effects , Meristem/drug effects , Meristem/growth & development , Mutation/genetics , Phosphates/pharmacology
14.
Genomics ; 103(1): 114-21, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24275521

ABSTRACT

Similar to the majority of the microRNAs, mature miR166s are derived from multiple members of MIR166 genes (precursors) and regulate various aspects of plant development by negatively regulating their target genes (Class III HD-ZIP). The evolutionary conservation or functional diversification of miRNA166 family members remains elusive. Here, we show the phylogenetic relationships among MIR166 precursor and mature sequences from three diverse model plant species. Despite strong conservation, some mature miR166 sequences, such as ppt-miR166m, have undergone sequence variation. Critical sequence variation in ppt-miR166m has led to functional diversification, as it targets non-HD-ZIPIII gene transcript (s). MIR166 precursor sequences have diverged in a lineage specific manner, and both precursors and mature osa-miR166i/j are highly conserved. Interestingly, polycistronic MIR166s were present in Physcomitrella and Oryza but not in Arabidopsis. The nature of cis-regulatory motifs on the upstream promoter sequences of MIR166 genes indicates their possible contribution to the functional variation observed among miR166 species.


Subject(s)
MicroRNAs/genetics , Phylogeny , RNA, Plant/genetics , Amino Acid Sequence , Arabidopsis/genetics , Bryopsida/genetics , Conserved Sequence , DNA, Plant/genetics , Evolution, Molecular , Genetic Variation , Molecular Sequence Data , Oryza/genetics , Promoter Regions, Genetic , Sequence Alignment , Sequence Analysis, RNA
15.
Physiol Plant ; 152(1): 1-16, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24410953

ABSTRACT

ETHYLMALONIC ENCEPHALOPATHY PROTEIN 1 (ETHE1) encodes sulfur dioxygenase (SDO) activity regulating sulfide levels in living organisms. It is an essential gene and mutations in ETHE1 leads to ethylmalonic encephalopathy (EE) in humans and embryo lethality in Arabidopsis. At present, very little is known regarding the role of ETHE1 beyond the context of EE and almost nothing is known about factors affecting its regulation in plant systems. In this study, we have identified, cloned and characterized OsETHE1, a gene encoding ETHE1-like protein from Oryza sativa. ETHE1 proteins in general are most similar to glyoxalase II (GLYII) and hence OsETHE1 has been earlier annotated as OsGLYII1, a putative GLYII gene. Here we show that OsETHE1 lacks GLYII activity and is instead an ETHE1 homolog being localized in mitochondria like its human and Arabidopsis counterparts. We have isolated and analyzed 1618 bp OsETHE1 promoter (pOsETHE1) to examine the factors affecting OsETHE1 expression. For this, transcriptional promoter pOsETHE1: 5-bromo-5-chloro-3-indolyl-ß-D-glucuronide (GUS) fusion construct was made and stably transformed into rice. GUS expression pattern of transgenic pOsETHE1:GUS plants reveal a high root-specific expression of OsETHE1. The pOsETHE1 activity was stimulated by Ca(II) and required light for induction. Moreover, pOsETHE1 activity was induced under various abiotic stresses such as heat, salinity and oxidative stress, suggesting a potential role of OsETHE1 in stress response.


Subject(s)
Calcium/metabolism , Dioxygenases/genetics , Gene Expression Regulation, Plant , Oryza/physiology , Stress, Physiological , Amino Acid Sequence , Dioxygenases/metabolism , Genes, Reporter , Light , Mitochondrial Proteins/genetics , Mitochondrial Proteins/metabolism , Molecular Sequence Data , Mutation , Onions/cytology , Onions/genetics , Onions/physiology , Organ Specificity , Oryza/drug effects , Oryza/genetics , Oryza/radiation effects , Phylogeny , Plant Epidermis/drug effects , Plant Epidermis/genetics , Plant Epidermis/physiology , Plant Epidermis/radiation effects , Plant Growth Regulators/pharmacology , Plant Proteins/genetics , Plant Proteins/metabolism , Plant Roots/drug effects , Plant Roots/genetics , Plant Roots/physiology , Plant Roots/radiation effects , Plants, Genetically Modified , Promoter Regions, Genetic/genetics , Recombinant Fusion Proteins , Sequence Alignment
16.
Plant Cell Rep ; 33(6): 945-53, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24504657

ABSTRACT

Overexpression of miR166/165 down-regulates target HD - ZIP IIIs and promotes root growth by enhancing cell division and meristematic activity, whereas overexpression of HD - ZIP IIIs inhibits root growth in Arabidopsis thaliana. Post-embryonic growth of higher plants is maintained by active meristems harbouring undifferentiated cells. Shoot and root apical meristems (SAM and RAM) utilize both similar and distinct signalling mechanisms for their maintenance in Arabidopsis thaliana. An important regulatory role in this context has the interaction of microRNAs with their target mRNAs, mostly encoding transcription factors. One class of microRNA166/165 (miR166/165) has been implicated in the maintenance of SAM and vascular patterning. Here, we show that miR166/165 plays an important role in root growth also by negatively regulating its target transcripts, HD-ZIP IIIs, in the RAM. While overexpression of miR166 promotes RAM activity, overexpression of its targets reduces RAM activity. These results reveal a conserved role of miR166/165 in the maintenance of SAM and RAM activity in A. thaliana.


Subject(s)
Arabidopsis Proteins/genetics , Arabidopsis/genetics , Gene Expression Regulation, Plant , MicroRNAs/genetics , Arabidopsis/growth & development , Arabidopsis Proteins/metabolism , Gene Expression , Homeodomain Proteins/genetics , Homeodomain Proteins/metabolism , Leucine Zippers , Meristem/genetics , Meristem/growth & development , Mutation , Plant Roots/genetics , Plant Roots/growth & development , Plants, Genetically Modified , RNA, Messenger/genetics , RNA, Plant/genetics
17.
Nature ; 446(7137): 811-4, 2007 Apr 12.
Article in English | MEDLINE | ID: mdl-17429400

ABSTRACT

Throughout the lifespan of a plant, which in some cases can last more than one thousand years, the stem cell niches in the root and shoot apical meristems provide cells for the formation of complete root and shoot systems, respectively. Both niches are superficially different and it has remained unclear whether common regulatory mechanisms exist. Here we address whether root and shoot meristems use related factors for stem cell maintenance. In the root niche the quiescent centre cells, surrounded by the stem cells, express the homeobox gene WOX5 (WUSCHEL-RELATED HOMEOBOX 5), a homologue of the WUSCHEL (WUS) gene that non-cell-autonomously maintains stem cells in the shoot meristem. Loss of WOX5 function in the root meristem stem cell niche causes terminal differentiation in distal stem cells and, redundantly with other regulators, also provokes differentiation of the proximal meristem. Conversely, gain of WOX5 function blocks differentiation of distal stem cell descendents that normally differentiate. Importantly, both WOX5 and WUS maintain stem cells in either a root or shoot context. Together, our data indicate that stem cell maintenance signalling in both meristems employs related regulators.


Subject(s)
Arabidopsis Proteins/metabolism , Arabidopsis/metabolism , Homeodomain Proteins/metabolism , Plant Roots/cytology , Plant Shoots/cytology , Signal Transduction , Stem Cells/cytology , Arabidopsis/anatomy & histology , Arabidopsis/cytology , Arabidopsis Proteins/genetics , Cell Differentiation , Conserved Sequence , Flowers/metabolism , Gene Expression Regulation, Plant , Homeodomain Proteins/genetics , Indoleacetic Acids/metabolism , Meristem/cytology , Meristem/metabolism , Molecular Sequence Data , Mutation/genetics , Plant Roots/metabolism , Plant Shoots/metabolism , Stem Cells/metabolism , Transcription Factors/metabolism
18.
Nanomaterials (Basel) ; 12(12)2022 Jun 18.
Article in English | MEDLINE | ID: mdl-35745438

ABSTRACT

In a hydroponic system, potassium chloroaurate (KAuCl4) triggers the in vitro sucrose (Suc)-dependent formation of gold nanoparticles (AuNPs). AuNPs stimulate the growth of the root system, but their molecular mechanism has not been deciphered. The root system of Arabidopsis (Arabidopsis thaliana) exhibits developmental plasticity in response to the availability of various nutrients, Suc, and auxin. Here, we showed the roles of Suc, phosphorus (P), and nitrogen (N) in facilitating a AuNPs-mediated increase in root growth. Furthermore, the recuperating effects of KAuCl4 on the natural (IAA) auxin-mediated perturbation of the root system were demonstrated. Arabidopsis seedlings harboring the cell division marker CycB1;1::CDB-GUS provided evidence of the restoration efficacy of KAuCl4 on the IAA-mediated inhibitory effect on meristematic cell proliferation of the primary and lateral roots. Arabidopsis harboring synthetic auxin DR5rev::GFP exhibited a reinstating effect of KAuCl4 on IAA-mediated aberration in auxin subcellular localization in the root. KAuCl4 also exerted significant and differential recuperating effects on the IAA-mediated altered expression of the genes involved in auxin signaling and biosynthetic pathways in roots. Our results highlight the crosstalk between KAuCl4-mediated improved root growth and Suc and nutrient-dependent auxin homeostasis in Arabidopsis.

19.
Methods Mol Biol ; 2238: 275-283, 2021.
Article in English | MEDLINE | ID: mdl-33471338

ABSTRACT

The success of single cell type-specific gene expression or functional study largely depends on the efficient isolation of high-quality RNA from them. Laser capture microdissection (LCM) is an efficient technique that allows accessing and dissecting out a specific individual cell or cell type from a microscopic heterogeneous tissue in a minimally disruptive way. Here, we describe an efficient and inexpensive LCM-based method for the extraction of RNAs with high yield and integrity from laser-microdissected mesophyll and bundle sheath cells of rice leaf. The integrity of isolated RNA is assessed with bioanalyzer analysis, and the presence of mRNA of a specific gene is validated through RT-PCR. This RNA could further be used for uncovering single cell type-specific gene expression signature using next-generation transcriptome sequence or through regular RT-PCR.


Subject(s)
Gene Expression Regulation, Plant , Laser Capture Microdissection/methods , Oryza/genetics , Plant Proteins/genetics , RNA, Plant/analysis , Single-Cell Analysis/methods , Gene Expression Profiling , Oryza/metabolism , Plant Proteins/metabolism , RNA, Plant/genetics , RNA, Plant/isolation & purification
20.
Sci Rep ; 10(1): 6163, 2020 Apr 06.
Article in English | MEDLINE | ID: mdl-32249798

ABSTRACT

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

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