Rice stripe disease, caused by rice stripe virus (RSV) which is transmitted by small brown planthopper (SBPH, Laodelphax striatellus Fallen), resulted in serious losses to rice production during the last 2 decades.  Research on the molecular differences between resistant and susceptible rice varieties and the interaction between rice and RSV remains inadequate.  In this study, RNA-Seq was used to analyze the transcriptomic differences between the resistant and susceptible rice varieties at different times post RSV infection.  Through Gene Ontology (GO) annotation, the differentially expressed genes (DEGs) related to transcription factors, peroxidases, and kinases of 2 varieties at 3 time points were identified.  Comparing these 2 varieties, the DEGs associated with these 3 GOs were numerically less in the resistant variety than in the susceptible variety, but the expression showed a significant up- or down-regulation trend under the conditions of |log₂(Fold change)|>0 & P_adj<0.05 by significance analysis.  Then through Kyoto Encyclopedia of Genes and Genomes (KEGG) annotation, DEGs involved in some pathways that have a contribution to disease resistance including plant hormone signal transduction and plant–pathogen interaction were found.  The results showed that resistance responses regulated by abscisic acid (ABA) and brassinosteroids (BR) were the same for 2 varieties, but that mediated by salicylic acid (SA) and jasmonic acid (JA)/ethylene (ET) were different.  The DEGs in resistant and susceptible varieties at the 3 time points were identified in both PAMP-triggered immunity (PTI) and Effector protein-triggered immunity (ETI), with that most of the unigenes of the susceptible variety were involved in PTI, whereas most of the unigenes of the resistant variety were involved in ETI.  These results revealed the different responses of resistant and susceptible varieties in the transcription level to RSV infection.

Identifying the sex pheromone systems of local pest populations facilitates their management, especially for moth species that show significant geographic variation in sex pheromone communication.  We investigated the pheromone production and behavioral responses of the Asian corn borer (Ostrinia furnacalis Guenée; ACB) in Xinjiang, China.  The ACB produces three compounds: (Z)-12-tetradecenyl acetate (Z12-14:Ac) and (E)-12-tetradecenyl acetate (E12-14:Ac) which are two sex pheromone compounds, and n-tetradecyl acetate (14:Ac) which has variable roles in mediating behavioral responses.  The ratios of these three compounds produced in female gland are geographically distinct among different populations.  Quantitative analysis of pheromone production showed that the proportions of Z12-14:Ac in the E/Z isomers (i.e., Z and E12-14:Ac) and the proportions of 14:Ac in the ternary blend respectively averaged 60.46% (SD=5.26) and 25.00% (SD=7.37), with their probabilities normally or near-normally distributed.  Trapping experiments in a cornfield indicated that deploying the E/Z isomers and the three compounds in rubber septa close to their gland ratios yielded the most captured males, while other ratios that deviated from the gland ratios showed reduced field captures.  The ternary blend was significantly more attractive to males than the E/Z isomers in the field, indicating a functional role of 14:Ac as the third pheromone component used by the local population.  Additionally, the dose-response test demonstrated that the application of the three compounds at dosages between 200 and 350 μg attracted significantly more males compared to other dosages.  Therefore, the characterization of this local ACB pheromone system provides additional information about its geographic variation and serves as a basis for optimizing the pheromone-mediated control of this pest in Xinjiang. 

The diversity of prokaryotic communities in soil is shaped by both biotic and abiotic factors.  However, little is known about the major factors shaping soil prokaryotic communities at a large scale in agroecosystems.  To this end, we undertook a study to investigate the impact of maize production cropping systems, soil properties and geographic location (latitude and longitude) on soil prokaryotic communities using metagenomic techniques, across four distinct maize production regions in China.  Across all study sites, the dominant prokaryotes in soil were Alphaproteobacteria, Gammaproteobacteria, Betaproteobacteria, Gemmatimonadetes, Acidobacteria, and Actinobacteria.  Non-metric multidimensional scaling revealed that prokaryotic communities clustered into the respective maize cropping systems in which they resided.  Redundancy analysis (RDA) showed that soil properties especially pH, geographic location and cropping system jointly determined the diversity of the prokaryotic communities.  The functional genes of soil prokaryotes from these samples were chiefly influenced by latitude, soil pH and cropping system, as revealed by RDA analysis.  The abundance of genes in some metabolic pathways, such as genes involved in microbe–microbe interactions, degradation of aromatic compounds, carbon fixation pathways in prokaryotes and microbial metabolism were markedly different across the four maize production regions.  Our study indicated that the combination of soil pH, cropping system and geographic location significantly influenced the prokaryotic community and the functional genes of these microbes.  This work contributes to a deeper understanding of the composition and function of the soil prokaryotic community across large-scale production systems such as maize.

Magnaporthe oryzae, the causal agent of blast diseases, is a destructive filamentous fungus that infects many plants including most economically important food crops, rice, wheat, pearl millet and finger millet.  Magnaporthe oryzae has numerous pathotypes because of its high host-specificity in the field.  The Oryza pathotype (MoO) of M. oryzae is the most devastating pathogen of rice, causing 10–30% yield loss in the world.  On the other hand, the Triticum pathotype (MoT) causes blast disease in wheat, which is now a serious threat to wheat production in some South American countries, Bangladesh and Zambia.  Because of low fungicide efficacy against the blast diseases and lack of availability of resistant varieties, control of rice and wheat blast diseases is difficult.  Therefore, an integrated management programme should be adopted to control these two diseases in the field.  Here, we introduced and summarized the classification, geographical distribution, host range, disease symptoms, biology and ecology, economic impact, and integrated pest management (IPM) programme of both rice and wheat blast diseases.Magnaporthe oryzae, the causal agent of blast diseases, is a destructive filamentous fungus that infects many plants including most economically important food crops, rice, wheat, pearl millet and finger millet.  Magnaporthe oryzae has numerous pathotypes because of its high host-specificity in the field.  The Oryza pathotype (MoO) of M. oryzae is the most devastating pathogen of rice, causing 10–30% yield loss in the world.  On the other hand, the Triticum pathotype (MoT) causes blast disease in wheat, which is now a serious threat to wheat production in some South American countries, Bangladesh and Zambia.  Because of low fungicide efficacy against the blast diseases and lack of availability of resistant varieties, control of rice and wheat blast diseases is difficult.  Therefore, an integrated management programme should be adopted to control these two diseases in the field.  Here, we introduced and summarized the classification, geographical distribution, host range, disease symptoms, biology and ecology, economic impact, and integrated pest management (IPM) programme of both rice and wheat blast diseases.

High nitrate (NO₃⁻) in vegetables, especially in leaf vegetables poses threaten to human health.  Selenium (Se) is an important element for maintaining human health, and exogenous Se application during vegetable and crop production is an effective way to prevent Se deficiency in human bodies.  Exogenous Se shows positive function on plant growth and nutrition uptake under abiotic and/or biotic stresses.  However, the influence of exogenous Se on NO₃⁻ accumulation in hydroponic vegetables is still not clear.  In the present study, hydroponic lettuce plants were subjected to six different concentrations (0, 0.1, 0.5, 5, 10 and 50 µmol L^–1) of Se as Na₂SeO₃.  The effects of Se on NO₃⁻ content, plant growth, and photosynthetic capacity of lettuce (Lactuca sativa L.) were investigated.  The results showed that exogenous Se positively decreased NO₃⁻ content and this effect was concentration-dependent.  The lowest NO₃⁻ content was obtained under 0.5 µmol L^–1 Se treatment.  The application of Se enhanced photosynthetic capacity by increasing the photosynthesis rate (P_n), stomatal conductance (Cs) and the transpiration efficiency (T_r) of lettuce.  The transportation and assimilation of NO₃⁻ and activities of nitrogen metabolism enzymes in lettuce were also analysed.  The NO₃⁻ efflux in the lettuce roots was markedly increased, but the efflux of NO₃⁻ from the root to the shoot was decreased after treated with exogenous Se.  Moreover, Se application stimulated NO₃⁻ assimilation by enhancing nitrate reductase (NR), nitrite reductase (NiR), glutamine synthetase (GS) and glutamate synthase enzyme (GOGAT) activities.  These results provide direct evidence that exogenous Se shows positive function on decreasing NO₃⁻ accumulation via regulating the transport and enhancing activities of nitrogen metabolism enzyme in lettuce.  We suggested that 0.5 µmol L^–1 Se can be used to reduce NO₃⁻ content and increase hydroponic lettuce yield. 

The difference between lycopene and phytohormone levels among diploid, triploid and tetraploid plants of two watermelon cultivars during fruit growth and ripening was studied.  The expression pattern of five genes (phytoene synthase (PSY1), phytoene desaturase (PDS), ζ-carotene desaturase (ZDS), carotenoid isomerase (CRTISO), and lycopene β-cyclase (LCYB)) was analyzed in details.  In red-fleshed cultivar Mimei, lycopene content increased rapidly from 25 to 35 days after pollination (DAP), and then decreased at 40 DAP.  Triploid and tetraploid fruit had higher levels of lycopene than diploid.  Moreover, triploid tended to contain more lycopene than tetraploid during fruit growth and ripening stages.  However, little amount of lycopene (0–2 mg kg^–1 fresh weight (FW)) in yellow-fleshed cultivar Huangmei was found during all fruit development stages.  In Mimei, transcript level of PSY1 was generally higher than the other four genes, and LCYB gene expression was the lowest among all five genes being tested.  PSY1, CRTISO and LCYB genes showed higher transcript levels in polyploid than in diploid fruit.  By contrast, in Huangmei, transcript level of LCYB was not the lowest, but only lower than that of PSY1.  PSY1, CRTISO and LCYB genes showed higher expression levels in diploid than in polyploid fruit.  In Mimei, the negative correlation between gibberellane (GA) content and lycopene accumulation was determined in all three different ploidy fruits, while a positive correlation was observed between abscisic acid (ABA) content and lycopene accumulation only in diploid watermelon.  These results indicated that different lycopene contents in different ploidy watermelons is regulated by the differential transcription expression of the lycopene metabolic genes and phytohormones. 

    Programmed cell death (PCD) plays a critical role in the development of plant pigment glands, while H₂O₂, which is a kind of reactive oxygen species (ROS) produced by the aerobic metabolism of cells, acts as an important signal in this process. Here, we investigated the temporal and spatial dynamics of accumulated H₂O₂ in pigment glands of Gossypium hirsutum L. with 3,3-diaminobenzidine (DAB) staining, 2’,7’-dichlorodihydrofluorescein diacetate (DCFH₂)-DA fluorescent labeling and CeCl₃ cytochemical localization techniques. The results showed that the pigment glands of G. hirsutum could generate H₂O₂, and the amount and localization of H₂O₂ varied at different developmental stages. At the early developmental stage, a small amount of HH₂O₂ accumulated in the vacuole membrane of pigment gland cells. At the intermediate stage, a large number of H₂O₂ appeared in the vacuole membrane, while cell walls started to accumulate a small amount of H₂O₂. When pigment gland cell degraded, H₂O₂ mainly accumulated on the chloroplast envelope membrane of inner sheath cells. With the degradation of the sheath cells, H₂O₂ was detected in cell wall and the membrane of secretory vesicles which contains the preliminary contents of pigment gland. With the pigment glands completely maturation, H₂O₂ would disappeared. The accumulation sites of H₂O₂ are consistent with the process of PCD of individual gland cells, which started from the degradation of intracellular membrane and ended with the degradation of cell walls. Thus H₂O₂ probably plays an important role in the development of pigment glands. In addition, the development of pigment glands and the generation of H₂O₂ are not associated with the light, and no H₂O₂ was detected in the secretions of pigment glands.

Rib eye muscle area (REMA) is an economically important trait and one of the main selection criteria for breeding in the swine industry. In the genome-wide association study (GWAS), the Illumina PorcineSNP60 BeadChip containing 62 163 single nucleotide polymorphisms (SNPs) was used to genotype 557 pigs from a porcine Large White×Minzhu intercross population. The REMA (at the 5th–6th, 10th–11th and the last ribs) was measured after slaughtered at the age of (240±7) d for each animal. Association tests between REMA trait and SNPs were performed via the Genome-Wide Rapid Association using the Mixed Model and Regression-Genomic Control (GRAMMAR-GC) approach. From the Ensembl porcine database, SNP annotation was implemented using Sus scrofa Build 10.2. Thirty-three SNPs on SSC12 and 3 SNPs on SSC2 showed significant association with REMA at the last rib at the chromosome-wide significance level. None of the SNPs of REMA at the 5th–6th rib and only a few numbers of the SNPs of REMA at the 10th–11th ribs were found in this study. The Haploview V3.31 program and the Haplo.Stats R package were used to detect and visualize haplotype blocks and to analyze the association of the detected haplotype blocks with REMA at the last rib. A linkage analysis revealed that 4 haplotype blocks contained 4, 4, 2, and 4 SNPs, respectively. Annotations from pig reference genome suggested 2 genes (NOS2, NLK) in block 1 (266 kb), one gene (TMIGD1) in block 2 (348 kb), and one gene (MAP2K4) in block 3 (453 kb). A functional analysis indicated that MYH3 and MYH13 genes are the potential genes controlling REMA at the last rib. We screened several candidate intervals and genes based on the SNPs location and the gene function, and inferred that NOS2 and NLK genes maybe the main genes of REMA at the last ribs.

Soil water is strongly affected by land use/cover in the Loess Plateau in China. Water stored in thick loessal soils is one of the most important resources regulating vegetation growth. However, soil water in the deep loess profile, which is critical for maintaining the function of the “soil water pool” is rarely studied because deep profile soil samples are difficult to collect. In this study, four experimental plots were established in 2005 to represent different farming systems on the Changwu Tableland: fallow land, fertilized cropland, unfertilized cropland, and continuous alfalfa. The soil water content in the 15-m-deep loess profiles was monitored continuously from 2007 to 2012 with the neutron probe technique. The results showed that temporal variations in soil water profiles differed among the four farming systems. Under fallow land, the soil water content increased gradually over time, first in the surface layers and later in the deep soil layers. In contrast, the soil water content decreased gradually under continuous alfalfa. The distributions of soil water in deep soil layers under both fertilized and unfertilized cropland were relatively stable over time. Thus farming system significantly affected soil water content. Seven years after the start of the experiment, the soil water contents in the 15-m-deep profiles averaged 23.4% under fallow land, 20.3% under fertilized cropland, 21.6% under unfertilized cropland, and 16.0% under continuous alfalfa. Compared to measurements at the start of the experiment, both fallow land and unfertilized cropland increased soil water storage in the 15-m loess profiles. In contrast, continuous alfalfa reduced soil water storage. Fertilized cropland has no significant effect on soil water storage. These results suggest that deep soil water can be replenished under the fallow and unfertilized farming systems. Dry soil layers (i.e., those which have soil water content less than the stable field water capacity) in the subsoil of the Changwu Tableland region can be classified as either temporary dry soil layers or persistent dry soil layers. Temporary dry soil layers, which typically form under annual crops, often disappear during wet years. Persistent dry soil layers generally develop under perennial vegetation. Even after removing the vegetation, persistent dry soil layers remain for several decades. This study provides information useful for the conservation and utilization of soil water resources in the Loess Tableland.

Soybean root and stem rot caused by Phytophthora sojae is a destructive disease worldwide. Using genetic resistance is an important and major component in the integrated pest management of this disease. To understand molecular mechanisms of root and stem rot resistance in soybeans, the gene and protein expression in hypocotyls and stems of variety Suinong 10 carrying resistance genes Rps1a and Rps2 was investigated by using mRNA differential display reverse transcription PCR and two-dimensional electrophoresis at 0, 0.5, 1, 2, and 4 h after inoculation with P. sojae race 1. The results of the comparison of gene and protein expression showed that at least eight differential fragments at the transcriptional level were related to metabolic pathway, phytoalexin, and signal transduction in defense responses.Sequence analyses indicated that these fragments represented cinnamic acid 4-hydroxylase gene, ATP β gene coding ATP synthase β subunit and ubiquitin-conjugating enzyme gene which upregulated at 0.5 h post inoculation, blue copper protein gene and UDP-N-acetyl-α-D-galactosamine gene which upregulated at 2 h post inoculation, TGA-type basic leucine zipper protein TGA1.1 gene, cyclophilin gene, and 14-3-3 protein gene which upregulated at 4 h post inoculation.Three resistance-related proteins, α-subunit and β-subunit of ATP synthase, and cytochrome P450-like protein, were upregulated at 2 h post inoculation. The results suggested that resistance-related multiple proteins and genes were expressed in the recognition between soybean and P. sojae during zoospore germination, penetration and mycelium growth of P. sojae in soybean.