scholarly journals OsSPL14/17 are required for phosphate-deficiency-inhibited tiller bud outgrowth by repression of PIN2 in rice

2021 ◽  
Author(s):  
Xiaoli Guo ◽  
Xiuli Zhu ◽  
Xuejiao Qi ◽  
Fan Feng ◽  
Guohua XU ◽  
...  
Keyword(s):  
Grain Yield ◽  
Strong Interaction ◽  
Phosphate Deficiency ◽  
Food Crops ◽  
Wild Type ◽  
Inhibitory Effects ◽  
P Deficiency ◽  
Transcriptional Inhibition ◽  
Essential Nutrient ◽  
Tiller Bud

Phosphorus (P) is an essential nutrient for food crops. P-deficiency inhibits tiller development of rice; thus, an understanding of the P-modulated tiller development mechanism is crucial for grain yield. Auxin and strigolactones (SLs) have been implicated as regulators of tiller formation in rice. However, the relationships between the two are unclear. We found that low-P (LP) inhibited rice tiller formation and tiller bud elongation, with higher levels of SLs. In contrast to wild-type (WT) plants, the number of tillers was greater in d10 (SL biosynthesis mutant), d14, and d53 (SL-responsive mutants) under LP conditions, demonstrating that D53 participates in LP- mediated inhibition of rice tiller formation. The strong interaction between D53 and SPL14/17 inhibited their transcriptional activities under normal P (NP) conditions, and mutation of SPL14/17 eliminated their inhibitory effects on tiller formation under LP conditions. SPL14/17 inhibited transcriptional from the PIN2 promoter, and overexpression of PIN2 induced tiller development under LP conditions. Therefore, binding of D53 to SPL14/17 represses their transcriptional inhibition, reversing SPL14/17-inhibited PIN2 transcription and promoting tiller development under NP conditions. Proteasomal degradation of D53 releases SPL14/17, thus repressing PIN2 transcription and preventing induction of tillering under LP conditions.

scholarly journals The Serratia marcescens Siderophore Serratiochelin Is Necessary for Full Virulence during Bloodstream Infection

2020 ◽  
Vol 88 (8) ◽  
Author(s):  
Danelle R. Weakland ◽  
Sara N. Smith ◽  
Bailey Bell ◽  
Ashootosh Tripathi ◽  
Harry L. T. Mobley
Keyword(s):  
Serratia Marcescens ◽  
Bloodstream Infection ◽  
Iron Acquisition ◽  
Gene Clusters ◽  
Clinical Isolates ◽  
Wild Type ◽  
Serratia Plymuthica ◽  
Content Type ◽  
Cas Assay ◽  
Essential Nutrient

ABSTRACT Serratia marcescens is a bacterium frequently found in the environment, but over the last several decades it has evolved into a concerning clinical pathogen, causing fatal bacteremia. To establish such infections, pathogens require specific nutrients; one very limited but essential nutrient is iron. We sought to characterize the iron acquisition systems in S. marcescens isolate UMH9, which was recovered from a clinical bloodstream infection. Using RNA sequencing (RNA-seq), we identified two predicted siderophore gene clusters (cbs and sch) that were regulated by iron. Mutants were constructed to delete each iron acquisition locus individually and in conjunction, generating both single and double mutants for the putative siderophore systems. Mutants lacking the sch gene cluster lost their iron-chelating ability as quantified by the chrome azurol S (CAS) assay, whereas the cbs mutant retained wild-type activity. Mass spectrometry-based analysis identified the chelating siderophore to be serratiochelin, a siderophore previously identified in Serratia plymuthica. Serratiochelin-producing mutants also displayed a decreased growth rate under iron-limited conditions created by dipyridyl added to LB medium. Additionally, mutants lacking serratiochelin were significantly outcompeted during cochallenge with wild-type UMH9 in the kidneys and spleen after inoculation via the tail vein in a bacteremia mouse model. This result was further confirmed by an independent challenge, suggesting that serratiochelin is required for full S. marcescens pathogenesis in the bloodstream. Nine other clinical isolates have at least 90% protein identity to the UMH9 serratiochelin system; therefore, our results are broadly applicable to emerging clinical isolates of S. marcescens causing bacteremia.

scholarly journals An MDM2 inhibitor achieves synergistic cytotoxic effects with adenoviruses lacking E1B55kDa gene on mesothelioma with the wild-type p53 through augmenting NFI expression

2021 ◽  
Vol 12 (7) ◽  
Author(s):  
Thao Thi Thanh Nguyen ◽  
Masato Shingyoji ◽  
Michiko Hanazono ◽  
Boya Zhong ◽  
Takao Morinaga ◽  
...  
Keyword(s):  
Wild Type ◽  
Inhibitory Effects ◽  
Cytotoxic Effects ◽  
P53 Expression ◽  
Nuclear Factor I ◽  
Infected Cells ◽  
Wild Type P53 ◽  
Mdm2 Inhibitor ◽  
P16 Expression

AbstractA majority of mesothelioma specimens were defective of p14 and p16 expression due to deletion of the INK4A/ARF region, and the p53 pathway was consequently inactivated by elevated MDM2 functions which facilitated p53 degradaton. We investigated a role of p53 elevation by MDM2 inhibitors, nutlin-3a and RG7112, in cytotoxicity of replication-competent adenoviruses (Ad) lacking the p53-binding E1B55kDa gene (Ad-delE1B). We found that a growth inhibition by p53-activating Ad-delE1B was irrelevant to p53 expression in the infected cells, but combination of Ad-delE1B and the MDM2 inhibitor produced synergistic inhibitory effects on mesothelioma with the wild-type but not mutated p53 genotype. The combination augmented p53 phosphorylation, activated apoptotic but not autophagic pathway, and enhanced DNA damage signals through ATM-Chk2 phosphorylation. The MDM2 inhibitors facilitated production of the Ad progenies through augmented expression of nuclear factor I (NFI), one of the transcriptional factors involved in Ad replications. Knocking down of p53 with siRNA did not increase the progeny production or the NFI expression. We also demonstrated anti-tumor effects by the combination of Ad-delE1B and the MDM2 inhibitors in an orthotopic animal model. These data collectively indicated that upregulation of wild-type p53 expression contributed to cytotoxicity by E1B55kDa-defective replicative Ad through NFI induction and suggested that replication-competent Ad together with augmented p53 levels was a therapeutic strategy for p53 wild-type mesothelioma.

scholarly journals Stress-induced expression of IPT gene in transgenic wheat reduces grain yield penalty under drought

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Ailin Beznec ◽  
Paula Faccio ◽  
Daniel J. Miralles ◽  
Leonor G. Abeledo ◽  
Cecilia Decima Oneto ◽  
...  
Keyword(s):  
Grain Yield ◽  
Bread Wheat ◽  
Transcriptional Control ◽  
Field Conditions ◽  
Wild Type ◽  
Ipt Gene ◽  
Receptor Like Kinase ◽  
Biomass Components ◽  
Yield Penalty ◽  
Wild Type Control

Abstract Background The heterologous expression of isopentenyl transferase (IPT) under the transcriptional control of the senescence-associated receptor-like kinase (SARK) promoter delayed cellular senescence and, through it, increased drought tolerance in plants. To evaluate the effect of pSARK::IPT expression in bread wheat, six independent transgenic events were obtained through the biolistic method and evaluated transgene expression, phenology, grain yield and physiological biomass components in plants grown under both drought and well-irrigating conditions. Experiments were performed at different levels: (i) pots and (ii) microplots inside a biosafety greenhouse, as well as under (iii) field conditions. Results Two transgenic events, called TR1 and TR4, outperformed the wild-type control under drought conditions. Transgenic plants showed higher yield under both greenhouse and field conditions, which was positively correlated to grain number (given by more spikes and grains per spike) than wild type. Interestingly, this yield advantage of the transgenic events was observed under both drought and well-watered conditions. Conclusions The results obtained allow us to conclude that the SARK promoter-regulated expression of the IPT gene in bread wheat not only reduced the yield penalty produced by water stress but also led to improved productivity under well-watered conditions.

scholarly journals Overexpression of OsPIN2 Regulates Root Growth and Formation in Response to Phosphate Deficiency in Rice

2019 ◽  
Vol 20 (20) ◽  
pp. 5144
Author(s):  
Huwei Sun ◽  
Xiaoli Guo ◽  
Fugui Xu ◽  
Daxia Wu ◽  
Xuhong Zhang ◽  
...  
Keyword(s):  
Root Growth ◽  
Growth And Development ◽  
Plant Root ◽  
Lateral Roots ◽  
Root Hairs ◽  
Phosphate Deficiency ◽  
P Deficiency ◽  
Auxin Distribution ◽  
Seminal Roots ◽  
Underlying Mechanisms

The response of root architecture to phosphate (P) deficiency is critical in plant growth and development. Auxin is a key regulator of plant root growth in response to P deficiency, but the underlying mechanisms are unclear. In this study, phenotypic and genetic analyses were undertaken to explore the role of OsPIN2, an auxin efflux transporter, in regulating the growth and development of rice roots under normal nutrition condition (control) and low-phosphate condition (LP). Higher expression of OsPIN2 was observed in rice plants under LP compared to the control. Meanwhile, the auxin levels of roots were increased under LP relative to control condition in wild-type (WT) plants. Compared to WT plants, two overexpression (OE) lines had higher auxin levels in the roots under control and LP. LP led to increased seminal roots (SRs) length and the root hairs (RHs) density, but decreased lateral roots (LRs) density in WT plants. However, overexpression of OsPIN2 caused a loss of sensitivity in the root response to P deficiency. The OE lines had a shorter SR length, lower LR density, and greater RH density than WT plants under control. However, the LR and RH densities in the OE lines were similar to those in WT plants under LP. Compared to WT plants, overexpression of OsPIN2 had a shorter root length through decreased root cell elongation under control and LP. Surprisingly, overexpression of OsPIN2 might increase auxin distribution in epidermis of root, resulting in greater RH formation but less LR development in OE plants than in WT plants in the control condition but levels similar of these under LP. These results suggest that higher OsPIN2 expression regulates rice root growth and development maybe by changing auxin distribution in roots under LP condition.

Growth and the distribution of phosphorus in wheat developed under various phosphorus and temperature regimes

1986 ◽  
Vol 37 (5) ◽  
pp. 459 ◽  
Author(s):  
GD Batten ◽  
IF Wardlaw ◽  
MJ Aston
Keyword(s):  
Grain Yield ◽  
Dry Matter ◽  
Flag Leaf ◽  
Standard Condition ◽  
Growth Period ◽  
Phosphorus Concentration ◽  
Floral Initiation ◽  
Stages Of Development ◽  
P Deficiency ◽  
P Supply

Experiments were designed to examine the effect of the level and duration of application of phosphorus (P) on yield in wheat and the effect of growth conditions prior to anthesis on the utilisation of P taken up during the early stages of development. In the first experiment, wheat (Triticum aestivum cv. Kite) was grown in sand and supplied with a complete nutrient solution containing either 1 mM phosphate or 0.25 mM phosphate. The supply of P was maintained until grain maturity, or stopped at different stages of development (floral initiation, flag leaf emergence, anthesis). The increase in total plant dry matter over this period ranged from 8.8 to 17.6 g/plant, with the 1.0 mM P supply and from 4.1 to 9.5 g/plant with the 0.25 mM P supply. Supply of P beyond anthesis resulted in more tiller dry matter and increased the P content of the grain, but did not increase grain yield at either level. With 1 mM P to maturity, up to 21% P of the grain P could be attributed to retranslocation of P within the plant after anthesis. With 0.25 mM P to floral initiation, 58% of the grain P could be attributed to such retranslocation. In a second experiment plants (cv. Kite) were grown initially at 18/13�C with 0.25 mM P until floral initiation and thereafter with a P-free solution until maturity. Between floral initiation and anthesis plants were placed in six dayhight temperatures, extending (in 3�C steps) from 15/10�C to 30/25OC, and then returned to the standard condition of 18/13�C. Higher pre-anthesis temperatures reduced the pre-anthesis growth period and the plant height, but increased the leaf phosphorus concentration and uptake of phosphorus per plant in both the pre- and post-anthesis periods. Net CO2 exchange indicated that leaf senescence in P-deficient plants was closely associated with the export of nitrogen as well as the export of P. Grain P increased from 0.15% to 0.3% when the preanthesis temperature was increased from 15/10 to 30/25�C, although grain yield per main culm did not vary greatly. These findings highlight the importance of environmental conditions in determining the level of P deficiency in wheat, and show that grain yield is not limited by the amount of P in the grain.

Effect of fertiliser phosphorus and nitrogen on the concentrations of oil and protein in grain and the grain yield of canola (Brassica napus L.) grown in south-western Australia

2007 ◽  
Vol 47 (8) ◽  
pp. 984 ◽  
Author(s):  
R. F. Brennan ◽  
M. D. A. Bolland
Keyword(s):  
Brassica Napus ◽  
Grain Yield ◽  
Western Australia ◽  
Field Experiments ◽  
Grain Production ◽  
Brassica Napus L ◽  
Single Superphosphate ◽  
P Deficiency ◽  
Soil P ◽  
Soil P Testing

The effect of fertiliser phosphorus (P) and nitrogen (N) on seed (grain) yield and concentration of oil and protein in grain of canola (oil-seed rape; Brassica napus L.) was measured in two field experiments undertaken at eight sites from 1993–2005 in south-western Australia, on soils deficient in P and N. Six rates of P (0–40 kg P/ha as single superphosphate) and four rates of N (0–138 kg N/ha as urea) were applied. Significant grain yield increases (responses) to applied P occurred in both experiments and these responses increased as rates of applied N increased. For grain production, the P × N interaction was significant in all eight years and locations of the two experiments. Application of P had no effect on concentration of oil and protein in grain. Application of N always decreased the concentration of oil and increased the concentration of protein in grain. For canola grain production in the region, responses to applied N always occur whereas responses to applied P are rare, but if soil P testing indicates likely P deficiency, both P and N fertiliser need to be applied.

scholarly journals Cloning, Expression, and Enzymatic Characterization of Pseudomonas aeruginosaTopoisomerase IV

1999 ◽  
Vol 43 (3) ◽  
pp. 530-536 ◽  
Author(s):  
Takaaki Akasaka ◽  
Yoshikuni Onodera ◽  
Mayumi Tanaka ◽  
Kenichi Sato
Keyword(s):  
Dna Gyrase ◽  
Fusion System ◽  
Enzymatic Characterization ◽  
Wild Type ◽  
Inhibitory Effects ◽  
Topoisomerase Iv ◽  
Upstream Gene ◽  
E Coli ◽  
New Quinolones

ABSTRACT The topoisomerase IV subunit A gene, parC homolog, has been cloned and sequenced from Pseudomonas aeruginosa PAO1, with cDNA encoding the N-terminal region of Escherichia coli parC used as a probe. The homolog and its upstream gene were presumed to be parC and parE through sequence homology with the parC and parE genes of other organisms. The deduced amino acid sequence of ParC and ParE showed 33 and 32% identity with that of the P. aeruginosa DNA gyrase subunits, GyrA and GyrB, respectively, and 69 and 75% identity with that of E. coli ParC and ParE, respectively. The putative ParC and ParE proteins were overexpressed and separately purified by use of a fusion system with a maltose-binding protein, and their enzymatic properties were examined. The reconstituted enzyme had ATP-dependent decatenation activity, which is the main catalytic activity of bacterial topoisomerase IV, and relaxing activities but had no supercoiling activity. So, the cloned genes were identified asP. aeruginosa topoisomerase IV genes. The inhibitory effects of quinolones on the activities of topoisomerase IV and DNA gyrase were compared. The 50% inhibitory concentrations of quinolones for the decatenation activity of topoisomerase IV were from five to eight times higher than those for the supercoiling activities ofP. aeruginosa DNA gyrase. These results confirmed that topoisomerase IV is less sensitive to fluoroquinolones than is DNA gyrase and may be a secondary target of new quinolones in wild-typeP. aeruginosa.

scholarly journals Yeast mitochondrial RNase P RNA synthesis is altered in an RNase P protein subunit mutant: insights into the biogenesis of a mitochondrial RNA-processing enzyme.

1996 ◽  
Vol 16 (7) ◽  
pp. 3429-3436 ◽  
Author(s):  
V Stribinskis ◽  
G J Gao ◽  
P Sulo ◽  
Y L Dang ◽  
N C Martin
Keyword(s):  
Rna Processing ◽  
Mitochondrial Protein ◽  
Rnase P ◽  
Mitochondrial Rna ◽  
Wild Type ◽  
Protein Subunit ◽  
Mitochondrial Trna ◽  
P Deficiency ◽  
F Gene ◽  
P Protein

Rpm2p is a protein subunit of Saccharomyces cerevisiae yeast mitochondrial RNase P, an enzyme which removes 5' leader sequences from mitochondrial tRNA precursors. Precursor tRNAs accumulate in strains carrying a disrupted allele of RPM2. The resulting defect in mitochondrial protein synthesis causes petite mutants to form. We report here that alteration in the biogenesis of Rpm1r, the RNase P RNA subunit, is another consequence of disrupting RPM2. High-molecular-weight transcripts accumulate, and no mature Rpm1r is produced. Transcript mapping reveals that the smallest RNA accumulated is extended on both the 5' and 3' ends relative to mature Rpm1r. This intermediate and other longer transcripts which accumulate are also found as low-abundance RNAs in wild-type cells, allowing identification of processing events necessary for conversion of the primary transcript to final products. Our data demonstrate directly that Rpm1r is transcribed with its substrates, tRNA met f and tRNAPro, from a promoter located upstream of the tRNA met f gene and suggest that a portion also originates from a second promoter, located between the tRNA met f gene and RPM1. We tested the possibility that precursors accumulate because the RNase P deficiency prevents the removal of the downstream tRNAPro. Large RPM1 transcripts still accumulate in strains missing this tRNA. Thus, an inability to process cotranscribed tRNAs does not explain the precursor accumulation phenotype. Furthermore, strains with mutant RPM1 genes also accumulate precursor Rpm1r, suggesting that mutations in either gene can lead to similar biogenesis defects. Several models to explain precursor accumulation are presented.

scholarly journals Evaluation of Low Phosphorus Tolerance of Rice Varieties in Northern Ghana

2015 ◽  
Vol 4 (4) ◽  
pp. 109 ◽  
Author(s):  
Williams Kwame Atakora ◽  
Mathias Fosu ◽  
S. O. Abebrese ◽  
Michael Asante ◽  
Matthias Wissuwa
Keyword(s):  
Grain Yield ◽  
Upland Rice ◽  
Dry Weight ◽  
Growth And Yield ◽  
Northern Ghana ◽  
P Deficiency ◽  
Days To Maturity ◽  
P Application ◽  
Phosphorus Application ◽  
Muriate Of Potash

<p>Phosphorus (P) deficiency is a major constraint to upland rice production on highly weathered, low activity clay soils in the humid zones of West Africa. There is a paucity of information on the short-term fertilizer P effects on rice on these soils. A field experiment was conducted in 2011 to determine the response of twenty-four (24) upland rice cultivars to fertilizer Phosphorus (P) applied at 0 and 60 kg P ha<sup>−1</sup>. An uncultivated field at SARI research area with available P (Bray 1) P content of 3.0 mg/kg was used for the experiment.</p> <p>The ploughed area was divided into two plots with one plot for +P and the other for -P treatment. Each of the 24 varieties was allocated three rows and spaced at 20 x 10 cm in four replications. The varieties were randomized for each replicate and planted on 2<sup>nd</sup> July 2011 at one seed per hill. Pre-emergence herbicide Pendimethaline 400 g/l (Alligator) was applied at 3.2 L/ha two days after planting followed by one hand weeding. For the (-) P plot, the entire field received N at 60 kg/ha as Sulphate of ammonia and K<sub>2</sub>O at 60 kg/ha as Muriate of Potash. For the (+) P plot, fertilizer was applied at NPK 60-60-60 kg/ha from Sulphate of ammonia, Triple superphosphate and Muriate of potash, respectively. For each plot, the N was split applied.</p> Results showed that the plants that received P were more vigorous and healthier. There was significant variety effect on number of tillers per plant (NOTPP), days to 50% flowering (DFF), days to maturity (DTM), dry weight of biomass (DWOB), number of panicles per plant (NOPPP), and grain yield per plant. Similarly, there was significant phosphorus effect on number of tillers per plant (NOTPP), days to 50% flowering (DFF), days to maturity (DTM), dry weight of biomass (DWOB), number of panicles per plant (NOPPP), and grain yield per plant. There was generally no interactive effect of variety by fertilizer except for DFF and DTM. The number of tillers per plant ranges from 3 – 16 with the overall mean without P application being 4 while overall mean with P application was 9. When P was applied, the number of days to 50 % flowering reduced from 86 days to 79 days. Days to maturity (DTM) was also reduced from 118 to 111 on average by P application. The varieties that were most tolerant to low P were ITA 257, Nerica 3 and TOX 1011-4-A2. The grain yield of ITA 257 remained the same whether P was applied or not. This is the variety that is best adapted to low P. We concluded that rice growth and yield components were affected by Phosphorus application. Plants that received phosphorus flowered and matured earlier. They also accumulated higher biomass and grain yield. ITA 257, Nerica 3 and TOX 1011-4-A2 were most tolerant to P deficiency.

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