Plant and Cell Physiology (Plant Cell Physiol)

Publisher: Nihon Shokubutsu Seiri Gakkai; Oxford University Press; HighWire Press, Oxford University Press (OUP)

Journal description

Plant and Cell Physiology is an international journal devoted to the publication of original papers in the biological sciences including: physiology biochemistry biophysics chemistry molecular biology cell biology and gene engineering of plants and micro-organisms.

Current impact factor: 4.98

Impact Factor Rankings

2015 Impact Factor Available summer 2015
2013 / 2014 Impact Factor 4.978
2012 Impact Factor 4.134
2011 Impact Factor 4.702
2010 Impact Factor 4.257
2009 Impact Factor 3.594
2008 Impact Factor 3.542
2007 Impact Factor 3.654
2006 Impact Factor 3.324
2005 Impact Factor 3.317
2004 Impact Factor 3.258
2003 Impact Factor 3.159
2002 Impact Factor 3.084
2001 Impact Factor 2.43
2000 Impact Factor 2.311
1999 Impact Factor 2.259
1998 Impact Factor 1.828
1997 Impact Factor 1.792
1996 Impact Factor 1.683
1995 Impact Factor 1.93
1994 Impact Factor 1.957
1993 Impact Factor 1.703
1992 Impact Factor 1.458

Impact factor over time

Impact factor
Year

Additional details

5-year impact 4.30
Cited half-life 7.90
Immediacy index 1.07
Eigenfactor 0.02
Article influence 1.35
Website Plant and Cell Physiology website
Other titles Plant & cell physiology (Online), Plant and cell physiology
ISSN 1471-9053
OCLC 45088618
Material type Document, Periodical, Internet resource
Document type Internet Resource, Computer File, Journal / Magazine / Newspaper

Publisher details

Oxford University Press (OUP)

  • Pre-print
    • Author can archive a pre-print version
  • Post-print
    • Author cannot archive a post-print version
  • Restrictions
    • 12 months embargo
  • Conditions
    • Pre-print can only be posted prior to acceptance
    • Pre-print must be accompanied by set statement (see link)
    • Pre-print must not be replaced with post-print, instead a link to published version with amended set statement should be made
    • Pre-print on author's personal website, employer website, free public server or pre-prints in subject area
    • Post-print in Institutional repositories or Central repositories
    • Publisher's version/PDF cannot be used
    • Published source must be acknowledged
    • Must link to publisher version
    • Set phrase to accompany archived copy (see policy)
    • Eligible authors may deposit in OpenDepot
    • The publisher will deposit in PubMed Central on behalf of NIH authors
    • Publisher last contacted on 19/02/2015
    • This policy is an exception to the default policies of 'Oxford University Press (OUP)'
  • Classification
    ​ yellow

Publications in this journal

  • [Show abstract] [Hide abstract]
    ABSTRACT: Liverworts occupy a basal position in the evolution of land plants, and are a key group to address a wide variety of questions in plant biology. Marchantia polymorpha is a common, easily cultivated, dioecious liverwort species, and is emerging as an experimental model organism. The haploid gametophytic generation dominates the diploid sporophytic generation in its life cycle. Genetically homogeneous lines in the gametophyte generation can be established easily and propagated through asexual reproduction, which aids genetic and biochemical experiments. Owing to its dioecy, male and female sexual organs are formed in separate individuals, which enables crossing in a fully controlled manner. Reproductive growth can be induced at desired times under laboratory conditions, which helps genetic analysis. The developmental process from a single-celled spore to a multicellular body can be observed directly in detail. As a model organism, molecular techniques for M. polymorpha are well developed, for example, simple and efficient protocols of Agrobacterium-mediated transformation have been established. Based on them, various strategies for molecular genetics, such as introduction of reporter constructs, overexpression, gene silencing, and targeted gene modification, are available. Herein, we describe the technologies and resources for reverse and forward genetics in M. polymorpha, which offer an excellent experimental platform to study the evolution and diversity of regulatory systems in land plants. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
    Plant and Cell Physiology 06/2015; DOI:10.1093/pcp/pcv097
  • [Show abstract] [Hide abstract]
    ABSTRACT: Methylation of ribosomal proteins has long been described in prokaryotes and eukaryotes but our knowledge about the enzymes responsible for these modifications in plants is scarce. The bacterial protein methyltransferase PrmA catalyzes the trimethylation of ribosomal protein L11 (RPL11) at three distinct sites. The role of these modifications is still unknown. Here, we show that PrmA from Arabidopsis thaliana (AtPrmA) is dually-targeted to chloroplasts and mitochondria. Mass spectrometry and enzymatic assays indicated that the enzyme methylates RPL11 in plasto- and mitoribosomes in vivo. We determined that the Arabidopsis and Escherichia coli PrmA enzymes share similar product specificity, making trimethylated residues, but, despite evolutionary relationship, display a difference in substrate site specificity. Contrarily to the bacterial enzyme that trimethylates the ε-amino group of two lysine residues and the N-terminal α-amino group, AtPrmA methylates only one lysine in the MAFCK(D/E)(F/Y)NA motif of plastidial and mitochondrial RPL11. The plant enzyme possibly methylates the N-terminus of plastidial RPL11, whereas mitochondrial RPL11 is N-α-acetylated by an unknown acetyltransferase. Last, we found that an Arabidopsis prma-null mutant is viable in standard environmental conditions and no molecular defect could be associated with a lack of RPL11 methylation in leaf chloroplasts or mitochondria. However, the conservation of PrmA during the evolution of photosynthetic eukaryotes together with the location of methylated residues at the binding site of translation factors to ribosomes suggests that RPL11 methylation in plant organelles could be involved, in combination with other post-translational modifications, in optimizing ribosome function. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
    Plant and Cell Physiology 06/2015; DOI:10.1093/pcp/pcv098
  • [Show abstract] [Hide abstract]
    ABSTRACT: Life cycle adaptation to seasonal variation in photoperiod and temperature is a major determinant of ecological success of widespread domestication of Arabidopsis thaliana. The circadian clock plays a role in the underlying mechanism for adaptation. Nevertheless, the mechanism by which the circadian clock track seasonal changes in photoperiod and temperature is a longstanding subject in the field. We previously showed that a set of the target genes (i.e., GI, LNK1. PRR9, PRR7) of the Evening Complex (EC) consisting of LUX-ELF3-ELF4 is synergistically induced in response to both the warm-night and night-light signals. Here, we further show that the responses occur within a wide range of growth compatible temperature (16°C to 28°C) in response to a small change in temperature (Δ4°C). A dim light pulse (less than 1 µmol m(-2) s(-1)) causes the enhanced effect on the transcription of EC targets. The night-light pulse antagonizes against a positive effect of the cool-night signal on the EC activity. This double-checking mechanism might enable plants to ignore (or tolerate) daily fluctuation of ambient temperature within a short interval in the natural habitats. Taken together, the EC nighttime repressor might play a physiological role in tracking seasonal variation in photoperiod and temperature by conservatively double-checking both the light and temperature conditions. Another EC target output gene PIF4 regulating plant morphologies is also regulated by both the temperature and light stimuli during the night. Hence, the EC nighttime repressor is implicated also in a physiological output of the PIF4-mediated regulation of morphologies in response to seasonal variation in photoperiod and ambient temperature. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
    Plant and Cell Physiology 06/2015; DOI:10.1093/pcp/pcv094
  • [Show abstract] [Hide abstract]
    ABSTRACT: Canola is an important vegetable oil crop globally, and the understanding of the molecular mechanism underlying fatty acids biosynthesis during seed embryo development is an important research goal. Here we report the transcriptional profiling analysis of developing canola embryos using RNA-sequencing (RNA-Seq) method. RNA-Seq analysis generated 58,579,451 sequence reads aligned with 32,243 genes. It was found that a total of 55 differential expression genes (DEGs) encoding 28 enzymes function in carbon flow to fatty acids of storage TAG. Most of the DEGs encoding above enzymes showed similar expression pattern, indicating the DEGs are cooperatively involved in carbon flow into fatty acids. In addition, 41 DEGs associated with signal transductions, transport and metabolic processing of auxin, gibberellin, abscisic acid, cytokinin and salicylic acids were found in the RNA-Seq database, which indicates the important roles of the phytohormones in controlling embryo development and fatty acids synthesis. 122 DEGs encoding transcriptional factor family members were found in developing canola embryos. Furthermore, BnDOF5.6, a zinc finger transcriptional factor gene, found in RNA-Seq database was down-regulated in developing canola embryos. The transgenic plants displayed reduced embryo sizes, decreased fatty acids contents and altered seed fatty acids composition in canola. Down-regulated of BnDof5.6 also changed the expression levels of genes involved in fatty acids synthesis and desaturation. Our results indicate that BnDof5.6 is required for embryo development and fatty acids synthesis in canola. Overall this study presents new information on the global expression patterns of genes during embryo development and will expand our understanding of the complex molecular mechanism of carbon flow into fatty acids and embryo development in canola. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
    Plant and Cell Physiology 06/2015; DOI:10.1093/pcp/pcv074
  • [Show abstract] [Hide abstract]
    ABSTRACT: Gene expression analysis is a key technology that is used to understand living systems. Multicellular organisms, including plants, are composed of various tissues and cell types, each of which exhibits a unique gene expression pattern. However, because of their rigid cell walls, plant cells are difficult to isolate from the whole plant. Although laser dissection has been used to circumvent this problem, the plant sample needs to be fixed beforehand, which presents several problems. In the present study, we developed an alternative method to conduct highly reliable gene expression profiling. First, we assembled a dissection apparatus that used a narrow, sharpened needle to automatically dissect out a micro-sample of fresh plant tissue (0.1-0.2 mm on a side) from a target site within a short time frame. Then, we optimized a protocol to synthesize a high-quality cDNA library on magnetic beads using a single micro-sample. The cDNA library was amplified and subjected to high-throughput sequencing. In this way, a stable and reliable system was developed to conduct gene expression profiling in small regions of a plant. The system was used to analyze the gene expression patterns at successive 50-μm intervals in the shoot apex of a 4-day-old Arabidopsis seedling. Clustering analysis of the data demonstrated that two small, adjacent domains, the shoot apical meristem and the leaf primordia, were clearly distinguishable. This system should be broadly applicable in the investigation of the spatial organization of gene expression in various contexts. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
    Plant and Cell Physiology 06/2015; DOI:10.1093/pcp/pcv078
  • [Show abstract] [Hide abstract]
    ABSTRACT: The sugar transporter (ST) plays an important role in plant growth, development, and fruit quality. In this study, a total of 75 ST genes were identified in the pear (Pyrus bretschneideri Rehd) genome based on systematic analysis. Furthermore, all ST genes identified were grouped into eight subfamilies according to conserved domains and phylogenetic analysis. Analysis of cis-regulatory element sequences of all ST genes identified the MYBCOREATCYCB1 promoter in sucrose transporter (SUT) and monosaccharide transporter (MST) genes of pear, while in grape, it is exclusively found in SUT subfamily members, indicating divergent transcriptional regulation in different species. Gene duplication event analysis indicated that whole genome duplication (WGD) and segmental duplication play key roles in ST gene amplification, followed by tandem duplication. Estimation of positive selection at codon sites of ST paralog pairs indicated that all plastidic glucose transporters (pGlcT) subfamily members have evolved under positive selection. In addition, the evolutionary history of ST gene duplications indicated that the ST genes have experienced significant expansion in the whole ST gene family after the second WGD, especially after apple and pear divergence. According to the global RNA-seq results of pear fruit development, gene expression profiling showed the expression of 53 STs. Combined with qRT-PCR analysis, two polyol/monosaccharide transporters (PLTs) and three tonoplast monosaccharide transporters (tMTs) members were identified as candidate genes, which may play important roles for sugar accumulation during pear fruit development and ripening. Identification of highly expressed STs in fruit is important for finding novel genes contributing to enhanced levels of sugar content in pear fruit. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
    Plant and Cell Physiology 06/2015; DOI:10.1093/pcp/pcv090
  • [Show abstract] [Hide abstract]
    ABSTRACT: Strigolactone (SL), auxin, and cytokinin (CK) interact to regulate shoot branching. CK has long been considered to be the only key phytohormone to promote lateral bud outgrowth. Here we report that gibberellin (GA) also acts as a positive regulator in the control of shoot branching in the woody plant Jatropha curcas. We show that GA and CK synergistically promote lateral bud outgrowth, and that both hormones influence the expression of putative branching regulators, J. curcas BRANCHED1 and BRANCHED2, which are key transcription factors maintaining bud dormancy. Moreover, treatment with paclobutrazol, an inhibitor of de novo GA biosynthesis, significantly reduced the promotion of bud outgrowth by CK, suggesting that GA is required for CK-mediated axillary bud outgrowth. In addition, SL, a plant hormone involved in the repression of shoot branching, acted antagonistically to both GA and CK in the control of lateral bud outgrowth. Consistent with this, the expression of JcMAX2, a J. curcas homolog of Arabidopsis MORE AXILLARY GROWTH 2 encoding an F-box protein in the SL signaling pathway, was repressed by GA and CK treatment. We also provide physiological evidences that GA also induces shoot branching in many other trees, such as papaya, indicating a more complicated regulating network occurs in the control of shoot branching in some perennial woody plants. © The Author(s) 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists.
    Plant and Cell Physiology 06/2015; DOI:10.1093/pcp/pcv089
  • [Show abstract] [Hide abstract]
    ABSTRACT: Transcriptional gene silencing (TGS) is often associated with promoter methylation in both animals and plants. However, the function of DNA methylation in intragenic region remains unclear. Here, we confirmed promoter methylation of Flowering locus T (FT) led to gene silencing; by contrast, we found that intragenic methylation triggered by RNA directed DNA methylation (RdDM) promoted FT expression. DNA methylation of FT gene body blocked FLC repressor binding to the CArG boxes. However, when the boxes were not directly targeted by inverted-repeat RNAs (IRs), FLC binding blocked spreading of DNA methylation to theses sequences. Notwithstanding the FLC binding, FT was still activated under this condition. The DNA methylation was accompanied by elevated H3K9 methylation levels on the FT gene body. More important, the FT diurnal and organ-specific expression pattern was preserved in the activated plants. Our data demonstrate that the same type of epigenetic modification can lead to opposite genetic outcome depending on the location of the modification on the gene locus. Moreover, we highlight a novel strategy to activate gene expression without changing its tempo-spatial regulatory patterns. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
    Plant and Cell Physiology 06/2015; DOI:10.1093/pcp/pcv091
  • [Show abstract] [Hide abstract]
    ABSTRACT: Sorbitol is a major product of photosynthesis in apple (Malus domestica) that is involved in carbohydrate metabolism and stress tolerance. However, little is known about how the global transcript levels in apple leaves respond to decreased sorbitol synthesis. In this study we used RNA-seq profiling to characterize the transcriptome of leaves from transgenic lines of the apple cultivar 'Greensleeves' exhibiting suppressed expression of aldose-6-phosphate reductase (A6PR) to gain insights into sorbitol function and the consequences of decreased sorbitol synthesis on gene expression. We observed that, although the leaves of the low sorbitol transgenic lines accumulate higher levels of various primary metabolites, only very limited changes were found in the levels of transcripts associated with primary metabolism. We suggest that this is indicative of post-transcriptional and/or post-translational regulation of primary metabolite accumulation and central carbon metabolism. However, we identified significantly enriched gene ontology terms belonging to the 'stress related process' category in the antisense lines (P value <0.05). These include genes involved in the synthesis/degradation of abscisic acid, salicylic acid and jasmonic acid, nucleotide binding site leucine-rich repeats (NBS-LRR) disease resistance genes and ABC transporter genes. This suggests that sorbitol plays a role in the responses of apple trees to abiotic and biotic stresses. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
    Plant and Cell Physiology 06/2015; DOI:10.1093/pcp/pcv092
  • [Show abstract] [Hide abstract]
    ABSTRACT: Sucrose (Suc) transporters (SUCs or SUTs) are important regulators in plant growth and stress tolerance. However, the mechanism of SUCs in plant abiotic stress resistance remains to be discovered. Here, we found that AtSUC9 expression was induced by abiotic stress, including salt, osmotic, and cold stress conditions. Disruption of AtSUC9 led to sensitive responses to abiotic stress during seed germination and seedling growth. Further analyses indicated that the sensitivity phenotype of Atsuc9s resulted from higher Suc content in shoots and lower Suc content in roots, as compared to that in wildtype (WT) plants. In addition, we found that the expression of AtSUC9 is specially induced by low levels of exogenous and endogenous Suc and deletion of AtSUC9 affected the expression of the low Suc level-responsive genes. AtSUC9 also showed an obvious response to treatments with low concentrations of exogenous Suc during seed germination, seedling growth, and Suc distribution, and Atsuc9s hardly grew in abiotic stress treatments without exogenous Suc. Moreover, our results illustrated deletion of AtSUC9 not only blocks abiotic stress-inducible abscisic acid (ABA) accumulation but also Atsuc9s had a lower content of endogenous ABA in stress conditions than in normal condition. Deletion of AtSUC9 also inhibited the expression of many ABA inducible genes (SnRk2.2/3/6, ABF2/3/4, ABI1/3/4, RD29A, KIN1 and KIN2). These results indicate that AtSUC9 is specially induced by low Suc levels then mediates the balance of Suc distribution and promotes ABA accumulation to enhance Arabidopsis abiotic stress resistance. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
    Plant and Cell Physiology 06/2015; DOI:10.1093/pcp/pcv082
  • [Show abstract] [Hide abstract]
    ABSTRACT: Most organisms capable of oxygenic photosynthesis have an aas gene encoding an acyl-acyl carrier protein synthetase (Aas), which activates free fatty acids (FFAs) via esterification to acyl carrier protein. Cyanobacterial aas mutants are often used for the studies aimed at photosynthetic production of biofuels because the mutation leads to intracellular accumulation of FFAs and their secretion into external medium, but the physiological significance of the production of FFAs and their recycling involving Aas has remained unclear. Using an aas-deficient mutant of Synechococcus elongatus strain PCC 7942, we show here that remodeling of membrane lipids is activated by high-intensity light and that the recycling of FFAs is essential for acclimation to high-light conditions; Unlike wild-type cells, the mutant cells could not increase the growth rate as the light intensity was increased from 50 to 400 μmol photons m(-2) s(-1) and the high-light-grown mutant cells accumulated FFAs and the lysolipids derived from all the four major classes of membrane lipids, revealing high-light-induced lipid deacylation. The high-light-grown mutant cells showed much lower PSII activity and chlorophyll contents as compared with the wild-type cells or low-light-grown mutant cells. The loss of Aas accelerated photodamage of PSII but did not affect the repair process of PSII, indicating that PSII is destabilized in the mutant. Thus, Aas is essential for acclimation of the cyanobacterium to high-light conditions. The relevance of the present findings to biofuel production using cyanobacteria is discussed. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
    Plant and Cell Physiology 06/2015; DOI:10.1093/pcp/pcv086
  • [Show abstract] [Hide abstract]
    ABSTRACT: SNC1 (SUPPRESSOR OF NPR1, CONSTITUTIVE 1) is one of a suite of intracellular Arabidopsis NOD-like receptor (NLR) proteins which, upon activation, result in the induction of defense responses. However, the molecular mechanisms underlying NLR activation and the subsequent provocation of immune responses are only partially characterized. To identify negative regulators of NLR-mediated immunity, a forward genetic screen was undertaken to search for enhancers of the dwarf, autoimmune gain-of-function snc1 mutant. To avoid lethality resulting from severe dwarfism, the screen was conducted using mos4 (modifier of snc1, 4) snc1 plants, which display wild-type-like morphology and resistance. M2 progeny were screened for mutant, snc1-enhancing (muse) mutants displaying a reversion to snc1-like phenotypes. The muse9 mos4 snc1 triple mutant was found to exhibit dwarf morphology, elevated expression of the pPR2-GUS defense marker reporter gene, and enhanced resistance to the oomycete pathogen Hyaloperonospora arabidopsidis Noco2. Via map-based cloning and Illumina sequencing, it was determined that the muse9 mutation is in the gene encoding the SWI/SNF chromatin remodeler SYD (SPLAYED), and was thus renamed syd-10. The syd-10 single mutant has no observable alteration from wild-type-like resistance, although the syd-4 T-DNA insertion allele displays enhanced resistance to the bacterial pathogen Pseudomonas syringae pv. maculicola ES4326. Transcription of SNC1 is increased in both syd-4 and syd-10. These data suggest that SYD plays a subtle, specific role in the regulation of SNC1 expression and SNC1-mediated immunity. SYD may work with other proteins at the chromatin level to repress SNC1 transcription; such regulation is important for fine-tuning the expression of NLR-encoding genes to prevent unpropitious autoimmunity.
    Plant and Cell Physiology 06/2015; DOI:10.1093/pcp/pcv087
  • [Show abstract] [Hide abstract]
    ABSTRACT: Peroxisomes are present in almost all plant cells. These organelles are involved in various metabolic processes, such as lipid catabolism and photorespiration. A notable feature of plant peroxisomes is their flexible adaptive responses to environmental conditions such as light. When plants shift from heterotrophic to autotrophic growth during the post-germinative stage, peroxisomes undergo a dynamic response, i.e., enzymes involved in lipid catabolism are replaced with photorespiratory enzymes. Although the detailed molecular mechanisms underlying the functional transition of peroxisomes have previously been unclear, recent analyses at the cellular level have enabled the unveiling of this detailed machinery. During the functional transition, obsolete enzymes are degraded inside peroxisomes by Lon protease, while newly-synthesized enzymes are transported into peroxisomes. In parallel, mature and oxidized peroxisomes are eliminated via autophagy; this functional transition occurs in an efficient manner. Moreover, it has become clear that quality control mechanisms are important for the peroxisomal response to environmental stimuli. In this review, we highlight recent advances in elucidating the molecular mechanisms required for the regulation of peroxisomal roles in response to changes in environmental conditions. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
    Plant and Cell Physiology 06/2015; DOI:10.1093/pcp/pcv081
  • [Show abstract] [Hide abstract]
    ABSTRACT: MALDI mass spectrometry imaging (MSI) or imaging mass spectrometry (imaging MS) has been a powerful tool to map the spatial distribution of molecules on the surface of biological materials. This technique has frequently been applied to animal tissue slices for the purpose of mapping proteins, peptides, lipids, sugars or small metabolites to find disease-specific bio-markers or to study drug metabolism. Recently, it has also been applied to intact plant tissues or thin slices thereof using commercial mass spectrometers. The present work is concerned with the refinement of MALDI/LDI-FTICR-MS incorporating certain specific features namely, ultra-high-mass resolution (> 100,000), ultra-high-molecular mass accuracy (< 1 ppm) and high-spatial resolution (< 10 μm) for imaging MS of plant tissues. Employing an in-house built mass spectrometer, the imaging MS analysis of intact Arabidopsis thaliana tissues namely, etiolated seedlings and roots of seedlings, glued to a small transparent ITO-coated conductive glass was performed. A matrix substance was applied to the vacuum dried intact tissues by sublimation prior to the imaging MS analysis. The images of various small metabolites representing their two dimensional (2D) distribution on the dried intact tissues were obtained with or without different matrix substances. The effects of MALDI matrices on the ionization of small metabolites during imaging MS acquisition are discussed. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
    Plant and Cell Physiology 06/2015; DOI:10.1093/pcp/pcv083
  • [Show abstract] [Hide abstract]
    ABSTRACT: The membrane trafficking pathway has been diversified in a specific way for each eukaryotic lineage, probably to fulfill specific functions in the organisms. In green plants, comparative genomics has supported the possibility that terrestrialization and/or multicellularization could be associated with the elaboration and diversification of membrane trafficking pathways, which have been accomplished by an expansion of the numbers of genes required for machinery components of membrane trafficking, including soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins. However, information regarding membrane trafficking pathways in basal land plant lineages remains limited. In the present study, we conducted extensive analyses of SNARE molecules, which mediate membrane fusion between target membranes and transport vesicles or donor organelles, in the liverwort, Marchantia polymorpha. The M. polymorpha genome contained at least 34 genes for 36 SNARE proteins, comprising fundamental sets of SNARE proteins that are shared among land plant lineages with low degrees of redundancy. We examined the subcellular distribution of a major portion of these SNARE proteins by expressing Citrine-tagged SNARE proteins in M. polymorpha, and the results showed that some of the SNARE proteins were targeted to different compartments from their orthologous products in Arabidopsis thaliana. For example, MpSYP12B was localized to the surface of the oil body, which is a unique organelle in liverworts. Furthermore, we identified three VAMP72 members with distinctive structural characteristics, whose N-terminal extensions contain consensus sequences for N-myristoylation. These results suggest that M. polymorpha has acquired unique membrane trafficking pathways associated with newly acquired machinery components during evolution.
    Plant and Cell Physiology 05/2015; DOI:10.1093/pcp/pcv076
  • [Show abstract] [Hide abstract]
    ABSTRACT: Isoflavone conjugates [7-O-β-d-glucosides and 7-O-(6”-malonyl-β-d-glucosides) of daidzein and genistein] accumulate in soybean roots and serve as the stored precursors of isoflavones (aglycons), which play very important roles in the rhizobia-mediated nodulation of this plant. Thus far, the isoflavone 7-O-glucosyltransferase (GmIF7GT or GmUGT1) has been biochemically characterized and is believed to be involved in isoflavone conjugate biosynthesis. The soybean genome encodes many other glycosyltransferase homologs (GmUGTs) that are related to GmUGT1; however, their catalytic properties, substrate specificities, and role(s) in isoflavone conjugation are unknown. In this study, nine different GmUGT1-related GmUGT cDNAs were isolated; six of these cDNAs belonged to two distinct phylogenetic subgroups (A and B), and these six were functionally characterized. The results showed that GmUGT4, a representative of subgroup A, encoded a UGT that was highly specific for isoflavones showing k cat and k cat/K m values for daidzein of 5.89±0.65 s-1 and 2.91 × 105 s-1M-1, respectively. Moreover, GmUGT4 was expressed in the roots (mainly in lateral roots) of the 7-day-old seedlings and seeds, both of which contained abundant amounts of isoflavone conjugates. By contrast, GmUGT1 and GmUGT7, which were subgroup B members, encoded enzymes with broad glucosyl-acceptor specificities and were mainly expressed in the aerial portions (cotyledons and hypocotyls) of the seedlings. In the present study, we proposed that the role of isoflavone glucosylation in a soybean plant is assigned to different GmUGT members in an organ/tissue-dependent manner. We also established the functional importance of GmUGT4 in the biosynthesis of isoflavone conjugates in lateral roots that make a major contribution to overall N2 fixation.
    Plant and Cell Physiology 05/2015; DOI:10.1093/pcp/pcv072
  • [Show abstract] [Hide abstract]
    ABSTRACT: Lotus is a vital aquatic ornamental plant with different flower colors. To explore the flower coloration mechanism in lotus, the constituents and contents of pigments in two lotus cultivars with red and white flowers were analyzed. Although flavones and flavonols were detected in both cultivars, anthocyanins could only be detected in red cultivar. A comparative proteomics analysis on the flower petals between these two cultivars was conducted. A total of 88 differentially expressed proteins were identified with 36 more abundant and 52 less abundant in red than white cultivar. Among them, four enzymes involved in anthocyanin pathway were identified, including flavanone 3-hydroxylase, anthocyanidin synthase, anthocyanidin 3-O-glucosyltransferase and glutathione S-transferase. Analysis on the expressional patterns of anthocyanin biosynthetic genes indicated that anthocyanindin synthase (ANS) gene might be the critical one determining the anthocyanins biosynthesis and accumulation in lotus flower. Further analysis showed that different methylation intensities on the promoter sequence of ANS gene might result in the different flower coloration in red and white cultivar. This study provides new insights into the mechanism of flower coloration in lotus, and may be helpful in its breeding and germplasm enhancement. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
    Plant and Cell Physiology 05/2015; DOI:10.1093/pcp/pcv077