- Fackel interacts with gibberellic acid signaling and vernalization to mediate flowering in Arabidopsis. [Journal Article]
- PPlanta 2017 Jan 20
- CONCLUSIONS: Fackel (FK) is involved in the flowering of Arabidopsis mainly via the gibberellin pathway and vernalization pathway. This new function of FK is partially dependent on the FLOWERING LOCUS C ( FLC ). A common transitional process from vegetative stage to reproductive stage exists in higher plants during their life cycle. The initiation of flower bud differentiation, which plays a key role in the reproductive phase, is affected by both external environmental and internal regulatory factors. In this study, we showed that the Arabidopsis weak mutant allele fk-J3158, impaired in the FACKEL (FK) gene, which encodes a C-14 reductase involved in sterol biosynthesis, had a long life cycle and delayed flowering time in different photoperiods. In addition, FK overexpression lines displayed an earlier flowering phenotype than that of the wild type. These processes might be independent of the downstream brassinosteroid (BR) pathway and the autonomous pathway. However, the fk-J3158 plants were more sensitive than wild type in reducing the bolting days and total leaf number under gibberellic acid (GA) treatment. Further studies suggested that FK mutation led to an absence of endogenous GAs in fk-J3158 and FK gene expression was also affected under GA and paclobutrazol (PAC) treatment. Moreover, the delayed flowering time of fk-J3158 could be rescued by a 3-week vernalization treatment, and the expression of FLOWERING LOCUS C (FLC) was accordingly down-regulated in fk-J3158. We also demonstrated that flowering time of fk-J3158 flc double mutant was significantly earlier than that of fk-J3158 under the long-day (LD) conditions. All these results indicated that FK may affect the flowering in Arabidopsis mainly via GA pathway and vernalization pathway. And these effects are partially dependent on the FLOWERING LOCUS C (FLC).
- Convergent repression of miR156 by sugar and the CDK8 module of Arabidopsis Mediator. [Journal Article]
- DBDev Biol 2017 Jan 18
- In Arabidopsis, leaves produced during the juvenile vegetative phase are simple, while adult leaves are morphologically complex. The juvenile to adult transition is regulated by miR156, a microRNA th...
In Arabidopsis, leaves produced during the juvenile vegetative phase are simple, while adult leaves are morphologically complex. The juvenile to adult transition is regulated by miR156, a microRNA that promotes juvenility by impeding the function of SPL transcription factors, which specify adult leaf traits. Both leaf derived sugars, as well as the Mediator Cyclin Dependent Kinase 8 (CDK8) module genes CENTER CITY (CCT)/MED12 and GRAND CENTRAL (GCT)/MED13, act upstream of miR156 to promote the juvenile to adult transition. However, it is not known whether sugar, CCT and GCT repress miR156 independently, as part of the same pathway, or in a cooperative manner. Here we show that sugar treatment can repress MIR156 expression in the absence of CCT or GCT. Both cct and the photosynthetic mutant chlorina1 (ch1) (which decreases sugar synthesis) exhibit extended juvenile development and increased MIR156A and MIR156C expression. Compared to ch1 and cct single mutants, the ch1 cct double mutant has a stronger effect on juvenile leaf traits, higher MIR156C levels, and a dramatic increase in MIR156A. Our results show that sugar and the CDK8 module are capable of regulating MIR156 independently, but suggest they normally act together in a synergistic manner.
- An Apple a Day. [Editorial]
- APActa Physiol (Oxf) 2017 Jan 19
- An Apple a Day keeps the Doctor Away - you may have heard the phrase more than once, as it has become so famous that translated versions circulate in a number of modern languages ["una mela al giorno...
An Apple a Day keeps the Doctor Away - you may have heard the phrase more than once, as it has become so famous that translated versions circulate in a number of modern languages ["una mela al giorno toglie il medico di torno"]. More than three millennia before the concept of vitamins became common knowledge, ancient Egyptian and Babylonian text described a diet of liver to cure night blindness (Dowling & Wald, 1958). However, it took mankind a very long time to, from there, discover vitamins. This article is protected by copyright. All rights reserved.
- Familiar auditory sensory training in chronic traumatic brain injury: a case study. [Journal Article]
- DRDisabil Rehabil 2017 Jan 19; :1-7
- CONCLUSIONS: The results emphasize the importance for continued evaluation and treatment of individuals in chronic states of seriously impaired consciousness with a variety of tools. Further study of auditory stimulation as a passive treatment paradigm for this population is warranted. Implications for Rehabilitation Clinicians should be equipped with treatment options to enhance neurobehavioral improvements when traditional treatment methods fail to deliver or maintain functional behavioral changes. Routine assessment is crucial to detect subtle changes in neurobehavioral function even in chronic states of disordered consciousness and determine potential preserved cognitive abilities that may not be evident due to unreliable motor responses given motoric impairments. Familiar Auditory Stimulation Training (FAST) is an ideal passive stimulation that can be supplied by families, allied health clinicians and nursing staff of all levels.
- RNA-Guided Cas9-Induced Mutagenesis in Tobacco Followed by Efficient Genetic Fixation in Doubled Haploid Plants. [Journal Article]
- FPFront Plant Sci 2016; 7:1995
- Customizable endonucleases are providing an effective tool for genome engineering. The resulting primary transgenic individuals (T0) are typically heterozygous and/or chimeric with respect to any mut...
Customizable endonucleases are providing an effective tool for genome engineering. The resulting primary transgenic individuals (T0) are typically heterozygous and/or chimeric with respect to any mutations induced. To generate genetically fixed mutants, they are conventionally allowed to self-pollinate, a procedure which segregates individuals into mutant heterozygotes/homozygotes and wild types. The chances of recovering homozygous mutants among the progeny depend not only on meiotic segregation but also on the frequency of mutated germline cells in the chimeric mother plant. In Nicotiana species, the heritability of Cas9-induced mutations has not been demonstrated yet. RNA-guided Cas9 endonuclease-mediated mutagenesis was targeted to the green fluorescent protein (GFP) gene harbored by a transgenic tobacco line. Upon retransformation using a GFP-specific guide RNA/Cas9 construct, the T0 plants were allowed to either self-pollinate, or were propagated via regeneration from in vitro cultured embryogenic pollen which give rise to haploid/doubled haploid plants or from leaf explants that form plants vegetatively. Single or multiple mutations were detected in 80% of the T0 plants. About half of these mutations proved heritable via selfing. Regeneration from in vitro cultured embryogenic pollen allowed for homozygous mutants to be produced more efficiently than via sexual reproduction. Consequently, embryogenic pollen culture provides a convenient method to rapidly generate a variety of genetically fixed mutants following site-directed mutagenesis. The recovery of a mutation not found among sexually produced and analyzed progeny was shown to be achievable through vegetative plant propagation in vitro, which eventually resulted in heritability when the somatic clones were selfed. In addition, some in-frame mutations were associated with functional attenuation of the target gene rather than its full knock-out. The generation of mutants with compromised rather than abolished gene functionality holds promise for future approaches to the conclusive functional validation of genes which are indispensible for the plant.
- Specific glucoside transporters influence septal structure and function in the filamentous, heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120. [Journal Article]
- JBJ Bacteriol 2017 Jan 17
- When deprived of combined nitrogen, some filamentous cyanobacteria contain two cell types: vegetative cells that fix CO2 through oxygenic photosynthesis and heterocysts that are specialized in N2 fix...
When deprived of combined nitrogen, some filamentous cyanobacteria contain two cell types: vegetative cells that fix CO2 through oxygenic photosynthesis and heterocysts that are specialized in N2 fixation. In the diazotrophic filament, the vegetative cells provide the heterocysts with reduced carbon (mainly in the form of sucrose) and heterocysts provide the vegetative cells with combined nitrogen. Septal junctions traverse peptidoglycan through structures known as nanopores, and appear to mediate intercellular molecular transfer that can be traced with fluorescent markers, including the sucrose analog esculin (a coumarin glucoside) that is incorporated into the cells. Uptake of esculin by the model heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120 was inhibited by the α-glucosides sucrose and maltose. Analysis of Anabaena mutants identified components of three glucoside transporters that move esculin into the cells: GlsC (Alr4781) and GlsP (All0261) are, respectively, an ATP-binding subunit and a permease subunit of two different ABC transporters, and HepP (All1711) is a major facilitator superfamily (MFS) protein that was shown previously to be involved in formation of the heterocyst envelope. Transfer of fluorescent markers (especially calcein) between vegetative cells of Anabaena was impaired by mutation of glucoside transporter genes. GlsP and HepP interact in bacterial two-hybrid assays with the septal junction-related protein SepJ, and GlsC was found to be necessary for formation of a normal number of septal peptidoglycan nanopores and for normal subcellular localization of SepJ. Therefore, beyond their possible role in nutrient uptake in Anabaena, glucoside transporters influence the structure and function of septal junctions.
- Ilex paraguariensis supplementation may be an effective nutritional approach to modulate oxidative stress during perimenopause. [Journal Article]
- EGExp Gerontol 2017 Jan 14
- Perimenopause is a period in a woman's life that precedes menopause and is characterized by hormonal changes that results in increased oxidative stress. Since oxidative stress is associated with age-...
Perimenopause is a period in a woman's life that precedes menopause and is characterized by hormonal changes that results in increased oxidative stress. Since oxidative stress is associated with age-related diseases and perimenopausal symptoms including somato-vegetative manifestations, nutritional antioxidant supplementation may be an effective approach to minimizing this stress. Mate tea (MT) (Ilex paraguariensis), a typical and inexpensive beverage consumed in the Brazilian south-east, Argentina and Uruguay, increases antioxidant defense. We hypothesized that MT could minimize oxidative stress during perimenopause by modulating enzymatic antioxidant defense. To test this, we analyzed the lipid oxidative damage and antioxidant defense in erythrocytes and liver of rats, after MT treatment. Female Wistar rats (aged 16 months) in proven perimenopause period received 20 mg/kg BW/day of mate tea, by gavage (PM + MT group) or water (PM group). Female rats aged 4 months (AD group) received water. Erythrocytes and liver were used to determine lipid oxidative damage, determined by malondialdehyde (MDA); superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) activites. Total plasma antioxidant capacity was examined by ferric reducing antioxidant power assay (FRAP) and estrogen by radioimmunoassay. MT increased FRAP and did not change estrogen levels. Increased SOD and GPx, and reduced MDA were observed in both tissues studied. Increased CAT activity was observed only in the liver. We confirmed the hypothesis that MT was capable of minimizing oxidative stress in this period of life by modulating antioxidant defense.
- Improved Arousal and Motor Function Using Zolpidem in a Patient with Space-Occupying Intracranial Lesions: a case report. [Journal Article]
- PM RPM R 2017 Jan 13
- Patients with disorders of consciousness (DOC) have profound functional limitations with few treatment options for improving arousal and quality of life. Zolpidem is a non-benzodiazepine hypnotic use...
Patients with disorders of consciousness (DOC) have profound functional limitations with few treatment options for improving arousal and quality of life. Zolpidem is a non-benzodiazepine hypnotic used to treat insomnia that has also been observed to paradoxically improve arousal in those with DOC, such as the vegetative or minimally conscious states (MCS). There is little information on its use in DOC patients with intracranial space occupying lesions. We present a case of a 24year old man in a MCS due to CNS lymphoma who was observed to have increased arousal and improved motor function following administration of zolpidem.
- Tomato SlERF.A1, SlERF.B4, SlERF.C3 and SlERF.A3, Members of B3 Group of ERF Family, Are Required for Resistance to Botrytis cinerea. [Journal Article]
- FPFront Plant Sci 2016; 7:1964
- The Ethylene-Responsive Factors (ERFs) comprise a large family of transcriptional factors that play critical roles in plant immunity. Gray mold disease caused by Botrytis cinerea, a typical necrotrop...
The Ethylene-Responsive Factors (ERFs) comprise a large family of transcriptional factors that play critical roles in plant immunity. Gray mold disease caused by Botrytis cinerea, a typical necrotrophic fungal pathogen, is the serious disease that threatens tomato production worldwide. However, littler is known about the molecular mechanism regulating the immunity to B. cinerea in tomato. In the present study, virus-induced gene silencing (VIGS)-based functional analyses of 18 members of B3 group (also called Group IX) in tomato ERF family were performed to identify putative ERFs that are involved in disease resistance against B. cinerea. VIGS-based silencing of either SlERF.B1 or SlERF.C2 had lethal effect while silencing of SlERF.A3 (Pit4) significantly suppressed vegetative growth of tomato plants. Importantly, silencing of SlERF.A1, SlERF.A3, SlERF.B4, or SlERF.C3 resulted in increased susceptibility to B. cinerea, attenuated the B. cinerea-induced expression of jasmonic acid/ethylene-mediated signaling responsive defense genes and promoted the B. cinerea-induced H2O2 accumulation. However, silencing of SlERF.A3 also decreased the resistance against Pseudomonas syringae pv. tomato (Pst) DC3000 but silencing of SlERF.A1, SlERF.B4 or SlERF.C3 did not affect the resistance to this bacterial pathogen. Expression of SlERF.A1, SlERF.A3, SlERF.B4, or SlERF.C3 was induced by B. cinerea and by defense signaling hormones such as salicylic acid, methyl jasmonate, and 1-aminocyclopropane-1-carboxylic acid (an ethylene precursor). SlERF.A1, SlERF.B4, SlERF.C3, and SlERF.A3 proteins were found to localize in nucleus of cells and possess transactivation activity in yeasts. These data suggest that SlERF.A1, SlERF.B4, and SlERF.C3, three previously uncharacterized ERFs in B3 group, and SlERF.A3, a previously identified ERF with function in immunity to Pst DC3000, play important roles in resistance against B. cinerea in tomato.
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- Heteroblastic Development of Transfer Cells is Controlled by the microRNA miR156/SPL Module. [Journal Article]
- PPPlant Physiol 2017 Jan 12
- We report that wall ingrowth deposition in phloem parenchyma (PP) transfer cells (TCs) in leaf veins of Arabidopsis thaliana (Arabidopsis) represents a novel trait of heteroblasty. Development of PP ...
We report that wall ingrowth deposition in phloem parenchyma (PP) transfer cells (TCs) in leaf veins of Arabidopsis thaliana (Arabidopsis) represents a novel trait of heteroblasty. Development of PP TCs involves extensive deposition of wall ingrowths adjacent to cells of the sieve element/companion cell (SE/CC) complex. These PP TCs potentially facilitate phloem loading by enhancing efflux of symplasmic sucrose for subsequent active uptake into cells of the SE/CC complex. PP TCs with extensive wall ingrowths are ubiquitous in mature cotyledons and juvenile leaves, but dramatically less so in mature adult leaves, an observation consistent with PP TC development reflecting vegetative phase change (VPC) in Arabidopsis. Consistent with this conclusion, the abundance of PP TCs with extensive wall ingrowths varied across rosette development in three ecotypes displaying differing durations of juvenile phase, and extensive deposition of wall ingrowths was observed in rejuvenated leaves following prolonged defoliation. PP TC development across juvenile, transition and adult leaves correlated positively with levels of miR156, a major regulator of VPC in plants, and corresponding changes in wall ingrowth deposition were observed when miR156 was overexpressed or its activity suppressed by target mimicry. Analysis of plants carrying miR156-resistant forms of SQUAMOSA PROMOTER BINDING PROTEIN LIKE (SPL) genes showed that wall ingrowth deposition was increased in SPL9-group but not SPL3-group genes, indicating that SPL9-group genes may function as negative regulators of wall ingrowth deposition in PP TCs. Collectively, our results point to wall ingrowth deposition in PP TCs being under control of the genetic program regulating VPC.