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81.
BUALUANG FAIYUE MOHAMMED J. AL‐AZZAWI TIMOTHY J. FLOWERS 《Plant, cell & environment》2010,33(5):702-716
Although an apoplastic pathway (the so‐called bypass flow) is implicated in the uptake of Na+ by rice growing in saline conditions, the point of entry of this flow into roots remains to be elucidated. We investigated the role of lateral roots in bypass flow using the tracer trisodium‐8‐hydroxy‐1,3,6‐pyrenetrisulphonic acid (PTS) and the rice cv. IR36. PTS was identified in the vascular tissue of lateral roots using both epifluorescence microscopy and confocal laser scanning microscopy. Cryo‐scanning electron microscopy and epifluorescence microscopy of sections stained with berberine‐aniline blue revealed that the exodermis is absent in the lateral roots. We conclude that PTS can move freely through the cortical layers of lateral roots, enter the stele and be transported to the shoot via the transpiration stream. 相似文献
82.
Ju Yeon Ban Su Kang Kim Sung Wook Kang Kyung Lim Yoon Joo-Ho Chung 《Life sciences》2010,86(19-20):756-759
AimsThis study was conducted to investigate the associations between single nucleotide polymorphisms (SNPs) of matrix metalloproteinases (MMPs) and Kawasaki disease (KD) in the Korean population.Main methodsA total 0f 101 KD patients and 306 healthy controls were examined. MMP7 (rs10502001, G/A, Arg77His), MMP11 (rs738792, T/C, Ala38Val), MMP12 (rs652438, A/G, Ile357Val) and MMP26 (rs2499953, A/G, Lys43Glu) genes were genotyped from the genomic DNA using direct sequencing. The results were then analyzed using logistic regression models, adjusting for gender as covariates.Key findingsThe four SNPs were in Hardy–Weinberg equilibrium. Only the MMP11 polymorphism (rs738792) was associated with KD. The SNP (rs738792) showed a statistically significant association with KD in the codominant (OR = 1.61, 95% CI = 1.11–2.34, P = 0.011) and dominant (OR = 1.92, 95% CI = 1.21–3.06, P = 0.006) models. However, there was no association between polymorphisms of other MMP genes and KD.SignificanceOverall, the results of this study indicate that MMP11 polymorphism may be associated with KD in the Korean population. 相似文献
83.
Hao Bing Li Guo Qiang Xie Jun Ma Gui Ru Liu Shu Min Wen Tomohiro Ban Sukumar Chakraborty Chun Ji Liu 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2010,121(5):941-950
Fusarium head blight (FHB) and crown rot (CR) are two wheat diseases caused by the same Fusarium pathogens. Progress towards CR resistance could benefit from FHB-resistant germplasm if the same genes are involved in resistance
to these two different diseases. Two independent studies were conducted to investigate the relationship between host resistances
to these two diseases. In the first study 32 genotypes were assessed and no significant correlation between their reactions
to FHB and CR was detected. The second study was based on a QTL analysis of a doubled haploid population derived from a variety
with resistance to both diseases. Results from this study showed that loci conferring resistance to FHB and CR are located
on different chromosomes. Together, these results suggest that, despite a common aetiology, different host genes are involved
in the resistance against FHB and CR in wheat. Thus, although it is possible that genes affecting both diseases may exist
in other germplasm or under different conditions, separate screening seems to be needed in identifying sources of CR resistance. 相似文献
84.
Oxidative stress affecting lipid membranes is considered to be closely related to cardiovascular disease and brain ischemia. In this study, we designed and synthesized membrane-localizing TEMPO derivatives and demonstrated that one of these synthesized probes, compound 1, localized and detected oxidative stress in the cell membrane in an endotoxic model of a mouse macrophage-like cell line. Compound 1 is therefore a potentially useful probe for evaluating oxidative stress at the cell membrane. 相似文献
85.
A fluorescent method was developed for the detection of unpaired and mismatched DNAs using a MutS-fluorophore conjugate. The fluorophore, 2-(4'-(iodoacetoamido)anilino) naphthalene-6-sulfonic acid (IAANS), was site-specifically attached to the 469 position of Thermus aquaticus (Taq.) MutS mutant (C42A/T469C). The fluorophore labeled residue located at the dimer interface of the protein undergoes a drastic conformational change upon binding with mismatched DNA. The close proximity of the two identical fluorescent molecules presumably causes the self-quenching of the fluorophore, since fluorescence emission of the biosensor decreases with increasing concentrations of mismatched DNA. The order of binding affinity for each unpaired and mismatched DNA obtained by this method was DeltaT (Kd=52 nM)>GT (62 nM)>DeltaC (130 nM)>CT (160 nM)>DeltaG (170 nM)>DeltaA (250 nM)>CC (720 nM)>AT (950 nM). This order is comparable to the previous results of the gel mobility shift assay. Thus, this method can be a simple, useful tool for elucidating the mechanism of DNA mismatch repair as well as a novel probe for detecting of genetic mutation. 相似文献
86.
Biochemical and structural studies of co-translational folding, targeting and translocation depend on an efficient methodology to prepare ribosome nascent chain complexes (RNCs). Here we present our approach for the generation of homogenous and stable RNCs involving in vitro translation and affinity purification. Fusing the SecM arrest sequence, which tightly interacts with the ribosomal tunnel, to the nascent polypeptide chain significantly enhanced the stability of the RNCs. We have been able to increase the yield of the affinity purification step by engineering a tag with higher affinity. The RNCs generated with this approach have been successfully used to obtain 3D cryo-electron microscopic reconstructions of complexes with the signal recognition particle and the translocon. The established procedure is highly efficient and if scaled up could yield milligram amounts of RNCs sufficient for crystallization experiments. 相似文献
87.
88.
Populations of the introduced Heracleum mantegazzianum consist of dense central stands, which gradually give way to open stands towards the margins. To analyse whether open stands
are due to unsuitable conditions or represent the invading front for further spread, we studied life-cycle, population dynamics,
stand structure and soil conditions of open and dense stands over two transition periods. Populations decreased during the
first interval but increased after the extremely dry and warm summer of 2003 during the second interval. Open stands had shorter
generation times, lower height, smaller proportions of small individuals and were less in equilibrium with the environment
than dense stands. In open stands, growth to higher stages was most important, while in dense stands delayed development (self-loops)
had a strong effect on population growth; stasis and fecundity contributed most to the difference in λ between stand types.
By petiole extension H. mantegazzianum may raise its leaves just above the resident vegetation. Therefore, younger stages develop faster in open stands, whereas
strong competition by conspecific adults leads to longer generation times and a higher proportion of small individuals in
dense stands. Disturbance due to extreme climatic conditions in summer 2003 equalised population dynamics of both stand types.
Life-cycle variation between stand types makes it difficult to infer simple management rules. However, our data suggest that
small and/or open stands of H. mantegazzianum may eventually serve as initials for further spread after land-use changes, whereas dense stands are stable and may represent
sources of propagules. 相似文献
89.
Marcel R. Eugster Laurent S. Morax Vanessa J. Hüls Simona G. Huwiler Alexandre Leclercq Marc Lecuit Martin J. Loessner 《Molecular microbiology》2015,97(1):33-46
Listeria monocytogenes is a bacterial pathogen classified into distinct serovars (SVs) based on somatic and flagellar antigens. To correlate phenotype with genetic variation, we analyzed the wall teichoic acid (WTA) glycosylation genes of SV 1/2, 3 and 7 strains, which differ in decoration of the ribitol‐phosphate backbone with N‐acetylglucosamine (GlcNAc) and/or rhamnose. Inactivation of lmo1080 or the dTDP‐l ‐rhamnose biosynthesis genes rmlACBD (lmo1081–1084) resulted in loss of rhamnose, whereas disruption of lmo1079 led to GlcNAc deficiency. We found that all SV 3 and 7 strains actually originate from a SV 1/2 background, as a result of small mutations in WTA rhamnosylation and/or GlcNAcylation genes. Genetic complementation of different SV 3 and 7 isolates using intact alleles fully restored a characteristic SV 1/2 WTA carbohydrate pattern, including antisera reactions and phage adsorption. Intriguingly, phage‐resistant L. monocytogenes EGDe (SV 1/2a) isolates featured the same glycosylation gene mutations and were serotyped as SV 3 or 7 respectively. Again, genetic complementation restored both carbohydrate antigens and phage susceptibility. Taken together, our data demonstrate that L. monocytogenes SV 3 and 7 originate from point mutations in glycosylation genes, and we show that phage predation represents a major driving force for serovar diversification and evolution of L. monocytogenes. 相似文献
90.
Hyojin Park Sungwoon Lee Pravesh Shrestha Jihye Kim Jeong Ae Park Yeongrim Ko Young Ho Ban Dae-Young Park Sang-Jun Ha Gou Young Koh Victor Sukbong Hong Naoki Mochizuki Young-Myeong Kim Weontae Lee Young-Guen Kwon 《The Journal of cell biology》2015,211(3):619-637
The phosphoinositide 3-kinase–Akt signaling pathway is essential to many biological processes, including cell proliferation, survival, metabolism, and angiogenesis, under pathophysiological conditions. Although 3-phosphoinositide–dependent kinase 1 (PDK1) is a primary activator of Akt at the plasma membrane, the optimal activation mechanism remains unclear. We report that adhesion molecule with IgG-like domain 2 (AMIGO2) is a novel scaffold protein that regulates PDK1 membrane localization and Akt activation. Loss of AMIGO2 in endothelial cells (ECs) led to apoptosis and inhibition of angiogenesis with Akt inactivation. Amino acid residues 465–474 in AMIGO2 directly bind to the PDK1 pleckstrin homology domain. A synthetic peptide containing the AMIGO2 465–474 residues abrogated the AMIGO2–PDK1 interaction and Akt activation. Moreover, it effectively suppressed pathological angiogenesis in murine tumor and oxygen-induced retinopathy models. These results demonstrate that AMIGO2 is an important regulator of the PDK1–Akt pathway in ECs and suggest that interference of the PDK1–AMIGO2 interaction might be a novel pharmaceutical target for designing an Akt pathway inhibitor. 相似文献