Osa-miR535 targets SQUAMOSA promoter binding protein-like 4 to regulate blast disease resistance in rice.

Many rice microRNAs have been identified as fine-tuning factors in the regulation of agronomic traits and immunity. Among them, Osa-miR535 targets SQUAMOSA promoter binding protein-like 14 (OsSPL14) to positively regulate tillers but negatively regulate yield and immunity. Here, we uncovered that Osa-miR535 targets another SPL gene, OsSPL4, to suppress rice immunity against Magnaporthe oryzae. Overexpression of Osa-miR535 significantly decreased the accumulation of the fusion protein SPL4TBS -YFP that contains the target site of Osa-miR535 in OsSPL4. Consistently, Osa-miR535 mediated the cleavage of OsSPL4 mRNA between the 10th and 11th base pair of the predicted binding site at the 3' untranslated region. Transgenic rice lines overexpressing OsSPL4 (OXSPL4) displayed enhanced blast disease resistance accompanied by enhanced immune responses, including increased expression of defense-relative genes and up-accumulated H2 O2 . By contrast, the knockout mutant osspl4 exhibited susceptibility. Moreover, OsSPL4 binds to the promoter of GH3.2, an indole-3-acetic acid-amido synthetase, and promotes its expression. Together, these data indicate that Os-miR535 targets OsSPL4 and OsSPL4-GH3.2, which may parallel the OsSPL14-WRKY45 module in rice blast disease resistance.

Rice miR1432 Fine-Tunes the Balance of Yield and Blast Disease Resistance via Different Modules.

microRNAs act as fine-tuners in the regulation of plant growth and resistance against biotic and abiotic stress. Here we demonstrate that rice miR1432 fine-tunes yield and blast disease resistance via different modules. Overexpression of miR1432 leads to compromised resistance and decreased yield, whereas blocking miR1432 using a target mimic of miR1432 results in enhanced resistance and yield. miR1432 suppresses the expression of LOC_Os03g59790, which encodes an EF-hand family protein 1 (OsEFH1). Overexpression of OsEFH1 leads to enhanced rice resistance but decreased grain yield. Further study revealed that miR1432 and OsEFH1 are differentially responsive to chitin, a fungus-derived pathogen/microbe-associated molecular pattern (PAMP/MAMP). Consistently, blocking miR1432 or overexpression of OsEFH1 improves chitin-triggered immunity responses. In contrast, overexpression of ACOT, another target gene regulating rice yield traits, has no significant effects on rice blast disease resistance. Altogether, these results indicate that miR1432 balances yield and resistance via different target genes, and blocking miR1432 can simultaneously improve yield and resistance.

Osa-miR162a fine-tunes rice resistance to Magnaporthe oryzae and Yield.

MicroRNAs (miRNAs) play essential roles in rice immunity against Magnaporthe oryzae, the causative agent of rice blast disease. Here we demonstrate that Osa-miR162a fine-tunes rice immunity against M. oryzae and yield traits. Overexpression of Osa-miR162a enhances rice resistance to M. oryzae accompanying enhanced induction of defense-related genes and accumulation of hydrogen peroxide (H2O2). In contrast, blocking Osa-miR162 by overexpressing a target mimic of Osa-miR162a enhances susceptibility to blast fungus associating with compromised induction of defense-related gene expression and H2O2 accumulation. Moreover, the transgenic lines overexpressing Osa-miR162a display decreased seed setting rate resulting in slight reduced yield per plant, whereas the transgenic lines blocking Osa-miR162 show an increased number of grains per panicle, resulting in increased yield per plant. Altered accumulation of Osa-miR162 had a limited impact on the expression of rice Dicer-like 1 (OsDCL1) in these transgenic lines showing normal gross morphology, and silencing of OsDCL1 led to enhanced resistance to blast fungus similar to that caused by overexpression of Osa-miR162a, suggesting the involvement of OsDCL1 in Osa-miR162a-regulated resistance. Together, our results indicate that Osa-miR162a is involved in rice immunity against M. oryzae and fine-tunes resistance and yield.

Expressing a Target Mimic of miR156fhl-3p Enhances Rice Blast Disease Resistance Without Yield Penalty by Improving SPL14 Expression.

MicroRNAs (miRNAs) play essential roles in the regulation of plant growth and defense responses. More and more, miRNA-3ps are reported to act in plant development and immunity. miR156 is a conserved miRNA, and most previous studies focus on its roles in plant growth, development, and yield determinacy. Here, we show that expressing a target mimic of miR156fhl-3p led to enhanced rice blast disease resistance without a yield penalty. miR156fhl-3p was differentially responsive to Magnaporthe oryzae in susceptible and resistant accessions. Transgenic lines expressing a target mimic of miR156fhl-3p (MIM156-3p) exhibited enhanced rice blast disease resistance and increased expression of defense-related genes. MIM156-3p also enhanced the mRNA abundance of SPL14 and WRKY45 by down-regulating miR156-5p and pre-miR156. Moreover, MIM156-3p lines displayed a decreased number of second rachis branches per panicle but enlarged grains, leading to unchanged yield per plant. Consistently, overexpressing miR156h (OX156) led to enhanced susceptibility to M. oryzae and decreased the expression of SPL14 and WRKY45. Our results indicate that miR156fhl-3p mounts a regulatory role on miR156-5p, which subsequently regulates the expression of SPL14 and WRKY45 to improve rice blast disease resistance.

Osa-miR1873 fine-tunes rice immunity against Magnaporthe oryzae and yield traits.

MicroRNAs (miRNAs) are known to fine-tune growth, development, and stress-induced responses. Osa-miR1873 is a rice-specific miRNA targeting LOC_Os05g01790. Here, we show that Osa-miR1873 fine-tunes rice immunity against Magnaporthe oryzae and yield traits via LOC_Os05g01790. Osa-miR1873 was significantly upregulated in a susceptible accession but downregulated in a resistance accession at 24 h post-inoculation (hpi) of M. oryzae. Overexpressing Osa-miR1873 enhanced susceptibility to M. oryzae and compromised induction of defense responses. In contrast, blocking Osa-miR1873 through target mimicry compromised susceptibility to M. oryzae and enhanced induction of defense responses. Altered expression of Osa-miR1873 also resulted in some defects in yield traits, including grain numbers and seed setting rate. Moreover, overexpression of the target gene LOC_Os05g01790 increased rice blast disease resistance but severely penalized growth and yield. Taken together, we demonstrate that Osa-miR1873 fine-tunes the rice immunity-growth trade-off via LOC_Os05g01790, and blocking Osa-miR1873 could improve blast disease resistance without significant yield penalty. Thus, the Osa-miR1873-LOC_Os05g01790 regulatory module is valuable in balancing yield traits and blast resistance.

Osa-miR398b boosts H2 O2 production and rice blast disease-resistance via multiple superoxide dismutases.

miRNAs contribute to plant resistance against pathogens. Previously, we found that the function of miR398b in immunity in rice differs from that in Arabidopsis. However, the underlying mechanisms are unclear. In this study, we characterized the mutants of miR398b target genes and demonstrated that multiple superoxide dismutase genes contribute to miR398b-regulated rice immunity against the blast fungus Magnaporthe oryzae. Out of the four target genes of miR398b, mutations in Cu/Zn-Superoxidase Dismutase1 (CSD1), CSD2 and Os11g09780 (Superoxide DismutaseX, SODX) led to enhanced resistance to M. oryzae and increased hydrogen peroxide (H2 O2 ) accumulation. By contrast, mutations in Copper Chaperone for Superoxide Dismutase (CCSD) resulted in enhanced susceptibility. Biochemical studies revealed that csd1, csd2 and sodx displayed altered expression of CSDs and other superoxide dismutase (SOD) family members, leading to increased total SOD enzyme activity that positively contributed to higher H2 O2 production. By contrast, the ccsd mutant showed CSD protein deletion, resulting in decreased CSD and total SOD enzyme activity. Our results demonstrate the roles of different SODs in miR398b-regulated resistance to rice blast disease, and uncover an integrative regulatory network in which miR398b boosts total SOD activity to upregulate H2 O2 concentration and thereby improve disease resistance.

[Wetting agent dosage screening for traditional Chinese medicine pellet based on torque rheological property].

With lubricant and bonding effect simultaneously, wetting agent has direct effect on properties of wet mass and extrudate, thus affecting the forming quality of pellets in extrusion-spheronization process. In this research, 25 representative kinds of traditional Chinese medicine(TCM) were selected as model drugs and 20%, 30% and 40% drug loading were set with MCC as their balling agent. The torque rheological curves were measured to get parameters such as maximum torque (Tmax) and corresponding water addition (WTmax) for these 75 raw materials by a mixer torque rheometer (MTR).The results showed that among 75 representative raw materials, 74 ones could be obtained for spherical pellets under the water addition of WTmax-2. corresponding to the second largest torque in torque rheological curve, suggesting that MTR could be used to select the optimal wetting agent dosage of TCM pellets. So the tedious and expensive pre-production work could be considerably reduced when TCM pellets were prepared.

An annular photobioreactor with ion-exchange-membrane for non-touch microalgae cultivation with wastewater.

To eliminate the negative impacts of pollutants in wastewater (such as suspended solids, excess N, P, heavy metals) on microalgae growth, an annular ion-exchange-membrane photobioreactor (IEM-PBR) was proposed in this study. The IEM-PBR could avoid direct mixing of algae cells with wastewater by separating them into two chambers. In the IEM-PBR, the nutrients (mainly N and P) in wastewater continuously permeated into microalgae cultures through the ion-exchange-membrane for microalgae growth, while the pollutants hardly permeated into microalgae cultures. Three types of representative wastewater were investigated to evaluate the performance of the IEM-PBR. When cultivated with wastewater containing excess nutrients, high turbidity and excess heavy metals, microalgae biomass concentrations were significantly improved from 2.34, 2.15 and 0gL(-1) in the traditional PBR to 4.24, 3.13 and 2.04gL(-1) in the IEM-PBR. Correspondingly, the removal efficiencies of N and P in wastewater were also greatly improved by using the IEM-PBR.

[Differences in nitrogen utilization characteristics of different peanut genotypes in high fertility soils]. / é«˜è‚¥åŠ›åœŸå£¤æ¡ä»¶ä¸‹ä¸åŒåŸºå› åž‹èŠ±ç”Ÿå¯¹æ°®ç´ åˆ©ç”¨çš„å·®å¼‚.

A total of twenty genotypes of peanut (Arachis hypogaea) were used to investigate the differences in nitrogen (N) utilization characteristics in a pot experiment with 15N isotope tracing analysis. Results showed the main N sources for peanut in high fertility soils following as soil N source > N fixed by root nodule source > fertilizer N source. The N uptake and accumulation in peanut from total N and the three N supplied sources (fertilizer N, soil N and N fixation) varied among the different genotypes. N fixation source had the largest genetic variation among the twenty genotypes while genetic variation for fertilizer N source and soil N source were lower and similar. Significant differences showed among the twenty genotypes in pod producing efficiency of N and N use efficiency, and the highest values were respectively 3.6 and 2.1 times of the lowest values. There were also significant differences among the twenty genotypes in the harvest indexes of total N, fertilizer N source, soil N source and N fixation source, and the largest variation showed in the harvest index of N fixation source. The pod yields significantly or extremely significantly corrected with N accumulation amounts from different N sources, N harvest index, pod producing efficiency of N, and N use efficiency. According to N uptake and accumulation and pod yield, four major types of peanut were classified, namely high total N accumulation high yield type, high fertilizer N source high yield type, high soil N source high yield type, and high N fixation source high yield type. Four of the twenty genotypes had all characteristics of the four major types.

Direct synthesis of solvent-free multiwall carbon nanotubes/silica nonionic nanofluid hybrid material.

The solvent-free nonionic nanofluid hybrid material consisting of multiwall carbon nanotubes (MWNTs) and silica nanoparticles is prepared by a facile route. The content of MWNTs/silica nanoparticles is up to 31 wt %. The hybrid material exhibits liquid-like behavior in the absence of solvent at 45 degrees C, which is a wax solid at room temperature. The process of melting and solidification is reversible over many cycles.

[Effects of omapatrilat on endothelin-1-induced proliferation and synthesis of cardiac fibroblasts].

AIM: To investigate the effects of omapatrilat (OMA) on endothelin-1-induced proliferation of cardiac fibroblasts (CFs). METHODS: Isolated and cultured CFs from neonatal Sprague-Dawley rats (SD) were randomly divided into 7 groups: (1) Control, (2) ET-1, (3) OMA, (4) ET-1 + OMA 10(-9) mol/L, (5) ET-1 + OMA 10(-8) mol/L, (6) ET-1 + OMA 10(-7) mol/L and (7) ET-1 + OMA 10(-6) mol/L. CFs were counted by MTT assay. Cell cycle distribution was determined with a flow cytometer (FCM). [3H]-Proline incorporation was evaluated by scintillation counting. Nitric oxide (NO) was measured by colorimetry. RESULTS: 10(-7) mol/L ET-1 significantly increased A490 value and [3H]-Pro incorporation and decreased NO secretion compared with the control group (P < 0.01). 10(-9)-10(-6) mol/L OMA inhibited the effects of ET-1 on CFs in a concentration-dependent manner (P < 0.01 vs. ET-1). In the ET-1 group, the percentage of cells in the S phase was higher than control, which was inhibited by l0(-6) mol/L OMA (P < 0.01 vs. ET-1 and control). CONCLUSION: OMA can restrain the proliferation and collagen synthesis of cardiac fibroblasts induced by endothelin-1, and this effect may be partially mediated by NO.

[Study on relationship between bent angles of dental fiber reinforced composites posts and their flexural properties].

OBJECTIVE: To develop a new type of fiber reinforced composites (FRC) posts with optimal bent angles. METHODS: Three kinds of experimental bent posts were made with bent angle of 5 degrees, 10 degrees, and 15 degrees respectively. The flexural strength of all FRC posts was tested with a 3-point bending test. RESULTS: The flexural strength of the posts with 15 degrees was significantly lower than that of 5 degrees and 10 degrees post groups and prefabricated straight group (P < 0.05). There was no significant difference in flexural strength within other groups (P > 0.05). CONCLUSIONS: The experimental FRC posts with bent angles of 0 degrees, 5 degrees, 10 degrees can be accepted clinically.