Root Endophyte Shift and Key Genera Discovery in Rice under Barnyardgrass Stress

Despite increasing knowledge of barnyardgrass(Echinochloa crus-galli) interference with rice, relatively little is known how endophytes improve the ability of rice against barnyardgrass stress. Here, we provided a detailed temporal characterization of rice root-associated microbiomes during co-cultivation with barnyardgrass and a comparison with the microbiomes of weed-free rice plants. Alpha diversity analysis indicated that barnyardgrass had the opposite effects on endophytic bacteria and fungi in rice roots, in terms of the community diversity, richness and coverage at the rice seedling stage. Principal coordinate analysis showed that barnyardgrass had only a minor effect on the community composition of endophytes in rice roots at the rice seedling stage, but showed a significant and maximum interference at the heading stage. Rice recruited many endophytes to resist biotic stress from barnyardgrass, especially for fungi. PICRUSt(phylogenetic investigation of communities by reconstruction of unobserved states) predictive analysis indicated that 23 metabolic pathways of bacteria were overrepresented in rice. In addition, the main trophic mode of fungi was pathotroph according to FUNGuild analysis. A positive correlation between bacteria and fungi in rice roots was found via network analysis. Anaeromyxobacter, Azospira and Pseudolabrys were the vital bacteria, Phaeosphaeria and Funneliformis were the dominant fungi in maintaining the stability of the ecological network. These results provided data and a theoretical basis for the in-depth understanding of what role endophytes play in rice resistance to barnyardgrass stress and will have implications on improving the resistance of rice against biotic stress using root microbiota.

Enhanced removal of nitrate and phosphate from wastewater by Chlorella vulgaris: Multi-objective optimization and CFD simulation

To enhance the efficiency of wastewater biotreatment with microalgae, the effects of physical parameters need to be investigated and optimized. In this regard, the individual and interactive effects of temperature, p H and aeration rate on the performance of biological removal of nitrate and phosphate by Chlorella vulgaris were studied by response surface methodology(RSM). Furthermore, a multi-objective optimization technique was applied to the response equations to simultaneously find optimal combinations of input parameters capable of removing the highest possible amount of nitrate and phosphate. The optimal calculated values were temperature of 26.3 °C, pH of 8 and aeration rate of 4.7 L·min^(-1). Interestingly, under the optimum condition, approximately 85% of total nitrate and 77% of whole phosphate were removed after 48 h and 24 h, respectively, which were in excellent agreement with the predicted values. Finally, the effect of baffle on mixing performance and, as a result, on bioremoval efficiency was investigated in Stirred Tank Photobioreactor(STP) by means of Computational Fluid Dynamics(CFD). Flow behavior indicated substantial enhancement in mixing performance when the baffle was inserted into the tank. Obtained simulation results were validated experimentally. Under the optimum condition, due to proper mixing in baffled STP, nitrate and phosphate removal increased up to 93% and 86%,respectively, compared to unbaffled one.

Quinclorac Resistance in Echinochloa crus-galli from China

Echinochloa crus-galli is a major weed in rice fields in China,and quinclorac has been long used for its control.Over-reliance of quinclorac has resulted in quinclorac resistance in E.crus-galli.Two resistant(R)E.crus-galli populations from Hunan,China were confirmed to be at least 78-fold more resistant to quinclorac than the susceptible(S)population.No difference in foliar uptake of 14C-labelled quinclorac was detected between the R and S plants.However,a higher level of 14C translocation and a lower level of quinclorac metabolism were found in the R plants.Basal and induced expression levels ofβ-cyanoalanine synthase(β-CAS)gene andβ-CAS activity were not significantly different between the R and S plants.However,the induction expression of 1-aminocyclopropane-1-carboxylic acid oxidase(ACO1)gene by quinclorac treatment was evident in the S plants but not in the R plants.Quinclorac resistance in the two resistant E.crus-galli populations was not likely to be related to foliar uptake,translocation or metabolism of quinclorac,nor to cyanide detoxification viaβ-CAS.Thus,target-site based quinclorac signal reception and transduction and regulation of the ethylene synthesis pathway should be the focus for further research.

The power of microsatellite markers and AFLPs in revealing the genetic diversity of Hashemi aromatic rice from Iran

Hashemi, a popular aromatic rice among Iranians, is famous for its fragrance and taste. Such features are major reasons for its higher price compared to non-aromatic varieties available in Iran. Therefore, the knowledge of genetic diversity of this profitable crop is a fundamental ineterst for plant breeders in future breeding programs. In the present research, genetic diversity among 35 genotypes of Hashemi aromatic rice （Oryza sativa L.） from Guilan and Mazandaran provinces of Iran was estimated using simple sequence repeat （SSR） and amplified fragment length polymorphism （AFLP） markers. Out of 21 SSR and 12 EcoRI-Msel AFLP marker combinations, only 16 SSRs and 10AFLPs exhibited polymorphic patterns while others were monomorphic. The 10 AFLP primer combinations produced a total of 142 of bands and 20 were polymorphic （14.08%）. Moreover, 40 out of 47 bands amplified with 16 SSR markers showed polymorphism （85.1%）. The average num- ber of alleles identified by SSR primers was 2.56 alleles per locus with a range of 2 to 4. The average value of polymorphic information content （PIC） was 0.393 and 0.468 for AFLP and SSR markers, respectively. However, the genetic similarity values ranged from 0.26 to 1 for SSRs and 0.21 to 1 forAFLPs. Later, a unweighted pair group method with arithmetic mean （UPGMA） dendrogram was generated and genotypes were clustered into four groups with SSRs at similarity coefficient of 0.55 while AFLPs clustered them into six groups at similarity coefficient of 0.41. Cluster analysis revealed a narrow genetic diversity and low correlation between geographical differentiation and genetic distance within cultivars.

Phylogeography and Characteristics of Phosphorus Efficiency of Secondary Core Collection for Rice Landraces in Yunnan Province

[Objective] The paper was to explore the causes of phosphorus(P)efficiency of rice in Yunnan Province,and to provide strategy for ecological and environmental protection.[Method]Using 703 accessions of secondary core collections from 16 prefectures of five regions in Yunnan Province,two treatments of low available P(6.26mg/kg)versus normal P(available P 40mg/kg),and invalid P(available P 0.02 mg/kg)versus normal P(available P 70 mg/kg)were set,and zonal characteristics of phosphorus efficiency and the activation characteristics of invalid P of rice landraces were investigated.[Result] Phosphorus efficiency and the activation characteristics of invalid P in soils from rice landraces of Yunnan Province had the similar identification indexes,viz.the relative indexes of four traits(tillering ability or effective panicle,root weight,biomass,and straw weight)could be the screening indexes of gene type of secondary core collection with phosphorus efficiency,which also reflected the zonal characteristics of phosphorus efficiency and the activation characteristics of invalid P in soils of 16 prefectures among five regions.On the contrary,the relative panicle length,node length under panicle,leaf length,leaf width and plant height could only be the assistant indexes of identification for phosphorus efficiency.There were similar zonal characteristics between phosphorus efficiency and the activation characteristics of invalid P in soils of rice landraces in Yunnan Province.[Conclusion] The study had great importance to the conservation and utilization of biological diversity,which would make contribution to second green revolution of "less input,multiple output,promote health,and protect the environment".

Effect of post-harvest UV-C irradiation and calcium chloride on enzymatic activity and decay of tomato(Lycopersicon esculentum L.)fruit during storage

Tomato is one of the extensively consumed vegetable crops worldwide. The regular consumption of tomato decreases the incidence of chronic degenerative diseases such as certain types of cancer and cardiovascular diseases. The objective of this study was to find an appropriate method that not only reduces tomatoes decay, but also maintains its post-harvest quality. A factorial experiment based on randomized complete block design with three replications was conducted to evaluate effects of ultraviolet（UV）-C and CaCl_2 applications on tomato during storage. The traits studied included ethylene, polygalacturonase（PG） activity, pectin methyl esterase（PME） activity, firmness, total phenol content, and fungal-induced decay were measured weekly during 35 days of storage. Both UV-C and CaCl_2 treatments had positive effects on tomato quality as compared to control treatment. The 3 and 4.5 k J m^（-2） levels of UV-C and 2% CaCl_2 had positive effects on quality characteristics, respectivly. Fruits treated by UV-C and CaCl_2 had higher phenol and firmness, and less PME activity, PG activity, ethylene production, and decay than the control fruits. In conclusion, increasing in storage duration significantly affected the fruits quality by increasing in ethylene, PME activity, PG activity, decay and decreasing the phenol content and firmness. But UV-C and CaCl_2 led to significant decrease in this adverse impact relative to control treatment.

Validation of EST-derived STS markers localized on Qfhs.ndsu-3BS for Fusarium head blight resistance in wheat using a‘Wangshuibai’derived population

A few EST-derived STS markers localized on Qfhs.ndsu-3BS, a major QTL for resistance to Fusarium head blight （FHB） in wheat, have been previously identified in the ＇Sumai 3＇/＇Stoa＇ population. In this study, we used a ＇Wangshuibai＇ （resistant）/＇Seri82＇ （susceptible） derived population, linkage group, QTL, and quantitative gene expression analysis to assess the genetic background dependence and stability of the EST-derived STS markers for use in marker aided selection to improve FHB resistance in wheat. Based on our results, a QTL in the map interval of Xsts3B-138_1-Xgwrn493 on chromosome 3BS was detected for FHB resistance, which accounted for up to 16% of the phenotypic variation. BLASTN analysis indicated that Xsts3B-138_1 sequence had significant similarity with the resistance gene analogue. Real-time quantitative PCR showed that the relative expression of Xsts3B-138_1 in ＇Wangshuibai＇ at 96 h after inoculation was 2.6 times higher than ＇Seri82＇. Our results underlined that EST-derived STS3B-138 markers could be predominantly used in marker aided selection to improve FHB resistance in wheat.

Synthesis,Crystal Structure and Insecticidal Activity of N-(pyridin-2-ylmethyl)-1-phenyl-1,4,5,6,7,8-hexahydrocyclohepta[c]pyrazole-3-carboxamide

The title compound N-（pyridin-2-ylmethyl）- 1-phenyl- 1,4,5,6,7,8-hexahydrocy-clohepta[c]pyrazole-3-carboxamide 5 （C21I-I22N40, Mr = 346.42） has been synthesized andstructurally characterized by IR, 1H NMR, 13C NMR, H RMS and single-crystal X-raydiffraction. The crystal crystallizes in monoclinic system, space group P21/n with a = 8.668（2）,b = 22.236（4）, c = 9.539（2） A, β = 108.68（3）°, V = 1786.4（7）/k3, Z = 4, Dx= 1.288 g/cm3,F（000） = 736,μ（MoKa） = 0.649 mm^-1, the final R = 0.0354 and wR = 0.0933 with 3234observed reflections with I 〉 2σ（/）. The benzene and pyrazole rings are nearly coplanar with adihedral angle of 50.977（46）°. The dihedral angle between the central pyrazole and pyridinerings is 11.688（46）°. No classical hydrogen bonds were found in the molecules. Two adjacentmolecules in crystal packing of compound 5 were linked by two intramolecularhydrogen-bonding interactions C（15）-H（15）…O（1） to generate a stable structure. Compound 5had weak insecticidal activity against the diamondback moth （Plutella xylostella）, butexhibited good activity against cotton bollworm （Helicoverpa armigera）.

Distinguished discriminatory separation of CO2 from its methane-containing gas mixture via PEBAX mixed matrix membrane

Highly selective separation of CO_2 from its methane-containing binary gas mixture can be achieved by using Poly(ether-block-amide)(PEBAX)mixed matrix membranes(MMMs).According to FESEM and AFM analyses,silica-based nanoparticles were homogenously integrated within the polymer matrix,facilitating penetration of CO_2 through the membrane while acting as barrier for methane gas.The membrane containing 4.6 wt% fumed silica(FS)(PEBAX/4.6 wt%FS)exhibits astonishing selectivity results where binary gas mixture of CO_2/CH_4 was used as feed gas.As detected by gas chromatography,in the permeate side,data showed a significant increase of CO_2 permeance,while CH_4 transport through the mixed matrix membrane was not detectable.Moreover,PEBAX/4.6 wt%FS greatly exceeds the Robeson limit.According to data reported on CO_2/CH_4 gas pair separation in the literature,the results achieved in this work are beyond those data reported in the literature,particularly when PEBAX/4.6 wt%FS membrane was utilized.

Optimization of micropropagation and <i>Agrobacterium</i>-mediated gene transformation to spinach (<i>Spinacia oleracea</i>L.)

Spinach is one of the dioecious plant which is considered as a model plant in genetic and molecular studies of sex determination because of its special characteristics such as low chromosome number and short life cycle. An efficient protocol for Spinacia oleracea Agrobacterium-mediated gene transformation was developed. The leaf disks, roots, hypocotyls and cotyledons of this plant were inoculated with LBA4404. LBA4404 carrying pCAMBIA3301 binary vector with 35SCaMV gusint and 35SCaMV bar cassettes. Effects of two preparation condition (induction of vir genes and noninduction) were considered. Also effects of different number days of co-cultivation and pre-culture of explants were examined. After co-cultivation, the explants were transferred to regeneration medium containing 250 mg·L-1 Carbeniciline. Transient expression efficiency was calculated based on the number of blue spots per explants one week after inoculation. Based on the results of transient expression, stable transformation was carried out. After formation of callus the histochemical GUS assay was carried out on some parts of them and other parts were leaved for being regenerated.

Evaluation of Genetic Diversity in Wild Diploid Wheat Triticum boeoticum from Iran Using AFLP Markers

Although Iran is a main center of distribution of wild wheats, but little information is available regarding genetic variation in wild wheat relatives from this country (Tabatabaei and Massoumi, 2001). The habitats of

Identification of Genetic Relationship of Hybrid Rice Varieties to Their Parents with PCR Products

[Objectives]To establish a simple,rapid and accurate method for identifying the genetic relationship of hybrid rice varieties to their parents.[Methods]Taking F1 hybrids Liangyou 336,Deliangyou Huazhan,and the parents of Liangyou 336,i.e.,C815S(♀)and R336(♂),as experimental materials,the genetic relationship of the hybrid rice varieties to the parental materials was identified by way of PCR amplification with the 48 pairs of SSR primers of Protocol for Identification of Rice Varieties:SSR Marker Method(NY/T 1433-2014).[Results]The genetic relationship of the hybrid rice varieties could be determined by comparing the PCR amplification products of the mixed DNA of the parents and the DNA of the F1 hybrids.[Conclusions]This method not only reduced the number of samples required but also had a good visual effect and high accuracy.

Variability of Deltamethrin-Resistant <i>Metarhizium anisopliae</i>Aggressive Strains Group to a Population of the Cossid Moth from <i>Eucalyptus nitens</i>

Random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) was used to examine the genetic variability among Metarhizium anisopliae isolates tested to the cossid moth, Coryphodema tristis. All the isolates tightly clustered into one or the other of two groups that diverged at 12%. Results suggested that certain genotypes of the fungus, that grouped together, were able to infect moth larvae while others did not. A fragment of 760 bp, which presents high homology with a host-adaptation related protein coding gene, distinguished between aggressive and non-aggressive isolates. Neither mycelial growth nor sporulation rate or presence of known virulence genes was correlated with mortality values. Some isolates, including the most aggressive isolate ARSEF2518, were compatible with deltamethrin. Deltamethrin treatment killed all the larvae after seven days whereas fungal and mixed treatments respectively reached the same mortality after 28 and 21 days.

Phase separation of GRP7 facilitated by FERONIAmediated phosphorylation inhibits mRNA translation to modulate plant temperature resilience

Changes in ambient temperature profoundly affect plant growth and performance.Therefore,the molecu-larbasis of plant acclimation to temperature fluctuation is of great interest.In this study,we discovered that GLYCINE-RICH RNA-BINDING PROTEIN 7(GRP7)contributes to cold and heat tolerance in Arabidopsis thaliana.We found that exposure to a warm temperature rapidly induces GRP7 condensates in planta,which can be reversed by transfer to a lower temperature.Cell biology and biochemical assays revealed that GRP7 undergoes liquid-liquid phase separation(LLPS)in vivo and in vitro.LLPS of GRP7 in the cyto-plasm contributes to the formation of stress granules that recruit RNA,along with the translation machinery component eukaryotic initiation factor 4E1(elF4E1)and the mRNA chaperones COLD SHOCK PROTEIN 1(CSP1)and CSP3,to inhibit translation.Moreover,natural variations in GRP7 affecting the residue phos-phorylated by the receptorkinase FERONIA alter its capacity to undergo LLPS and correlate with the adap-tation of some Arabidopsis accessions to a widertemperature range.Taken together,ourfindings illustrate the role of translational control mediated by GRP7 LLPS to confer plants with temperature resilience.

Effects of plant growth-promoting rhizobacteria on the molecular responses of maize under drought and heat stresses: A review

Drought and heat are major environmental stresses that continually influence plant growth and development. Under field conditions, these stresses occur more frequently in combination than alone, which magnifies corresponding detrimental effects on the growth and productivity of agriculturally important crops. Plant responses to such abiotic stresses are quite complex and manifested in a range of developmental, molecular, and physiological modifications that lead either to stress sensitivity or tolerance/resistance. Maize (Zea mays L.) is known for its sensitivity to abiotic stresses, which often results in substantial loss in crop productivity. Bioaugmentation with plant growth-promoting rhizobacteria (PGPR) has the potential to mitigate the adverse effects of drought and heat stresses on plants. Hence, this is considered a promising and eco-friendly strategy to ensure sustainable and long-term maize production under adverse climatic conditions. These microorganisms possess various plant growth-promoting (PGP) characteristics that can induce drought and heat tolerance in maize plants by directly or indirectly influencing molecular, metabolic, and physiological stress responses of plants. This review aims to assess the current knowledge regarding the ability of PGPR to induce drought and heat stress tolerance in maize plants. Furthermore, the drought and heat stress-induced expression of drought and heat stress response genes for this crop is discussed with the mechanisms through which PGPR alter maize stress response gene expression.

Taxonomy and pathogenicity of Ceratocystis species on Eucalyptus trees in South China, including C. chinaeucensis sp. nov.

Commercial plantations of Eucalyptus species have been established in South China,especially during the past 20 years,to meet the needs of a rapidly growing national economy.As part of a survey of fungal diseases affecting Eucalyptus species in South China,Ceratocystis species were collected from Eucalyptus plantations in the GuangDong Province.The aims of this study were to identify these Ceratocystis isolates and to test their pathogenicity to Eucalyptus.The most aggressive isolates were also used to screen different species and clones of Eucalyptus for susceptibility to infection under field conditions.The fungi were identified based on morphology and through comparisons of DNA sequence data of the ITS,partialβ-tubulin and TEF-1αgene regions.Morphological and DNA sequence comparisons showed that isolates collected from Chinese Eucalyptus plantations represent two species,C.acaciivora in the C.fimbriata s.l.species complex and a previously undescribed species belonging to the C.moniliformis s.l.species complex,for which the name C.chinaeucensis sp.nov.is provided.In pathogenicity trials,both C.acaciivora and C.chinaeucensis gave rise to lesions on wounded Eucalyptus trees,and the former fungus was most pathogenic.Differences were also observed in the responses of different Eucalyptus clones to inoculation and this could be useful in reducing disease,if C.acaciivora should emerge as a pathogen in the future.

Quambalaria species associated with eucalypt diseases in southern China

The genus Quambalaria includes several important pathogens of species of Eucalyptus and Corymbia, mainly causing leaf and shoot blight. Recently,extensive shoot and leaf dieback and stem cankers suspected to be Quambalaria diseases have been found on young Eucalyptus urophylla ? E. grandis trees in Guangdong and Hainan Provinces. The occurrence of Quambalaria species and their association with eucalypt hosts within China needs to be investigated for tree diseases management. The isolates from the diseased samples were identified based on their morphological structures and phylogenetic analyses with DNA sequence data for the internal transcribed spacer region and large ribosome subunit RNA of the nuclear r DNA. This work revealed that three species of Quambalaria were present: Quambalaria pitereka from Corymbia citriodora,Q. eucalypti from E. urophylla ? E. grandis, both isolated from young eucalypt leaves and shoots in Guangdong Province, and Quambalaria simpsonii, which was isolated from stem cankers of E. urophylla ? E. grandis at four different sites across Guangdong and Hainan Provinces.These results confirmed that Quambalaria agents were associated with the diseases occurring on eucalypt hosts in South China. This is the first report of Q. eucalypti in Asia and the first report of Q. simpsonii in China on Eucalyptus trees.

Expression of Acyl-lipid 12-desaturase Gene in Prokaryotic and Eukaryotic Cells and Its Effect on Cold Stress Tolerance of Potato

We report the expression profile of acyl-lipid △12-desaturase （desA） gene from Synechocystis sp. PCC6803 and its effect on cell membrane lipid composition and cold tolerance in prokaryotic （Escherichia coil） and eukaryotic （Solanum tuberosum） cells. For this purpose, a hybrid of desA and reporter gene encoding thermostable lichenase （licBM3） was constructed and used to transform these cells. The expression of this hybrid gene was measured using qualitative （Petri dish test, electrophoregram and zymogram） and quantitative methods （spectrometry and gas liquid chromatography assays）. The maximum level of linoleic acid in the bacterial cells containing hybrid gene was 1.9% of total fatty acids. Cold stress tolerance assays using plant damage index and growth parameters showed that cold tolerance was enhanced in primary transgenic lines because of increased unsaturated fatty acid concentration in their lipids. The greatest content of 18：2 and 18：3 fatty acids in primary transgenic plants was observed for lines 2 （73%） and 3 （41%）. Finally, our results showed that desaturase could enhance tolerance to cold stress in potato, and desaturase and lichenase retain their functionality in the structure of the hybrid protein where the enzymatic activity of target gene product was higher than in the case of reporter lichenase gene absence in the construction.

Mate-recognition and species boundaries in the ascomycetes

Reproductive gene evolution is commonly invoked as a source of reproductive isolation during speciation.This possibility has not been adequately explored in the Ascomycota,the most species-rich fungal phylum.The mechanisms of mate-recognition in this group are relatively simple:a“mating type”locus determines reproductive mode and sexual compatibility,and two pheromone/receptor pairs control sexual attraction.However,ascomycete reproductive genes can experience unique and interesting evolutionary forces,which could lead to rapid divergence.In this review,we examine the mechanisms of sexual interaction in ascomycetes and explore current evidence as to whether these mechanisms allow for species-specificity in mate-recognition.We discuss the evolutionary forces that can drive reproductive gene divergence,how these may apply in the world of ascomycetes,and their possible consequences for speciation.