For various sexually mature insects, including the brown planthopper (BPH, Nilaparvata lugens), the abdominal vibration (AV) signal is the initiation of the mating process, and it is critical to the success of mating.  Currently, there are few studies on the genetic and molecular mechanisms of AV regulation.  Our previous AV-related transcriptomic study in female BPH identified myoinhibitory peptide (NlMIP) as a gene that potentially affects AV status in females, but how NlMIP affects AV status remains unknown.  In this study, we confirmed that NlMIP regulates AV production and mating behavior in female BPH.  When the RNAi knockdown efficiency of NlMIP was 59.00%, the probability of females producing AV and the mating rate in 1 h decreased by 38.89 and 61.11%, respectively.  In addition, six mature peptides of NlMIP were synthesized and they were able to regulate AV production and mating behavior in females, with NlMIP2 having the strongest effect.  The A-family neuropeptide GPCR 10 (NlA10) was found to be a potential receptor for NlMIP based on a phylogenetic tree analysis and the fact that NlMIP mature peptides effectively activated NlA10.  After NlA10 was knocked down, the probability of females producing AV and the mating rate in 1 h had reductions of 28.89 and 43.33%, respectively.  When activated by NlMIP2, NlA10 coupled the Gαi/q signalling pathways, thereby inhibiting the downstream AC/cAMP/PKA, activating the PLC/Ca²⁺/PKC signalling pathways and then activating MEK1/2 in a cascade to mediate the phosphorylation of ERK1/2, and finally regulating the AV of females.  These results provide a basis for the prevention and control of the brown planthopper pest by disrupting female AV.

Sucrose nonfermenting-related protein kinase 1 (SnRK1) is one of the critical serine/threonine protein kinases.  It commonly mediates plant growth and development, cross-talks with metabolism processes and physiological responses to biotic or abiotic stresses.  It plays a key role in distributing carbohydrates and sugar signal transporting.  In the present study, eight SnRK1 coding genes were identified in sorghum (Sorghum bicolor L.) via sequences alignment, with three for α subunits (SnRK1α1 to SnRK1α3), three for β (SnRK1β1 to SnRK1β3), and one for both γ (SnRK1γ) and βγ (SnRK1βγ).  These eight corresponding genes located on five chromosomes (Chr) of Chr1–3, Chr7, and Chr9 and presented collinearities to SnRK1s from maize and rice, exhibiting highly conserved domains within the same subunits from the three kinds of cereals.  Expression results via qRT-PCR showed that different coding genes of SnRK1s in sorghum possessed similar expression patterns except for SnRK1α3 with a low expression level in grains and SnRK1β2 with a relatively high expression level in inflorescences.  Results of subcellular localization in sorghum leaf protoplast showed that SnRK1α1/α2/α3/γ mainly located on organelles, while the rest four of SnRK1β1/β2/β3/βγ located on both membranes and some organelles.  Besides, three combinations were discovered among eight SnRK1 subunits in sorghum through yeast two hybrid, including α1-β2-βγ, α2-β3-γ, and α3-β3-γ.  These results provide informative references for the following functional dissection of SnRK1 subunits in sorghum.

 

Nitrogen (N) is a critical element for plant growth and productivity that influences photosynthesis and chlorophyll fluorescence. We investigated the effect of low-N stress on leaf photosynthesis and chlorophyll fluorescence characteristics of maize cultivars with difference in tolerance to low N levels. The low-N tolerant cultivar ZH311 and low-N sensitive cultivar XY508 were used as the test materials. A field experiment (with three N levels: N0, 0 kg ha^–1; N1, 150 kg ha^–1; N2, 300 kg ha^–1) in Jiyanyang, Sichuan Province, China, and a hydroponic experiment (with two N levels: CK, 4 mmol L^–1; LN, 0.04 mmol L^–1) in Chengdu, Sichuan Province, China were conducted. Low-N stress significantly decreased chlorophyll content and rapid light response curves of the maximum fluorescence under light (F_m´), fluorescence instable state (F_s), non-photochemical quenching (q_N), the maximum efficiency of PSII photochemistry under dark-adaption (F_v/F_m), potential activity of PSII (F_v/F_o), and actual photochemical efficiency of PSII (ΦPSII) of leaves. Further, it increased the chlorophyll (Chl) a/Chl b values and so on. The light compensation point of ZH311 decreased, while that of XY508 increased. The degree of variation of these indices in low-N tolerant cultivars was lower than that in low-N sensitive cultivars, especially at the seedling stage. Maize could increase Chl a/Chl b, apparent quantum yield and light saturation point to adapt to N stress. Compared to low-N sensitive cultivars, low-N tolerant cultivars maintained a higher net photosynthetic rate and electron transport rate to maintain stronger PSII activity, which further promoted the ability to harvest and transfer light. This might be a photosynthetic mechanism by which low-N tolerant cultivar adapt to low-N stress.

    H9N2 avian influenza virus (AIV) infection is a major problem in poultry industry worldwide. In this study, molecular characterizations and phylogenetic relationships of hemagglutinin (HA) gene sequences of H9N2 AIV of 5 Chinese isolates in 2014 recently available in GenBank, 3 widely used vaccine strains, and 52 novel isolates in China from 2013 to 2015 were analyzed. The homology analysis showed that the nucleotide sequences of HA gene of these recent Chinese H9N2 AIV isolates shared homologies from 94.1 to 99.9%. Phylogenetic analysis showed that all isolates belonged to AIV lineage h9.4.2.5. Fifty-six out of the 57 recent Chinese H9N2 AIV isolates had the motifs PSRSSR↓GLF at the cleavage sites within the HA protein, while one isolate PWH01 harbored LSRSSR↓GLF. Remarkably, all of the recent Chinese H9N2 AIV strains had the Q216L substitution in the receptor binding site, which indicated that they had potential to infect humans. Most of recent Chinese H9N2 AIV isolates lost the potential N-linked glycosylation site at residues 200–202 compared with vaccine strains. This present study demonstrated that AIV lineage h9.4.2.5 was more predominant in China than other lineages as it harbored all the H9N2 AIV isolated between 2013 and 2015. Also we showed the importance of continuous surveillance of emerging H9N2 AIV in China and update of vaccine formulation accordingly in order to prevent and control H9N2 AIV.

Bulk-SSR method was used to analyze the genetic diversity of 44 open-pollinated varieties collected from Henan, Shandong, Shanxi, and Jilin provinces and Guangxi Zhuang Autonomous Region, China using 70 pairs of SSR primers. The purposes of this study were to (1) compare the genetic diversity among 44 Chinese maize open-pollinated varieties; (2) estimate the minimum number of alleles for construction of a stable dendrogram; and (3) trace the genetic relationships among local germplasm from different regions of China. In total, these 70 SSR primers yielded 292 alleles in 176 samples (4×44) analyzed. The number of alleles per locus was 4.17 on average and ranged from 2 to 8. The highest number of alleles per open-pollinated variety (55.25) was detected in Shanxi germplasm, which indicated that open-pollinated varieties from Shanxi possessed the largest genetic diversity among those from the five locations. The correlation coefficients between different genetic similarity matrices suggested that 200 alleles were sufficient for analysis of the genetic diversity of these 44 open-pollinated varieties. The cluster analysis showed that 44 open-pollinated varieties collected from three growing regions in China were accurately classified into three groups that were highly consistent with their geographic origins, and there is no correlation between GS and geographic distance in this study.

This paper reported firstly successful cloning of lycopene ε-cyclase (IbLCYe) gene from sweetpotato, Ipomoea batatas (L.) Lam. Using rapid amplification of cDNA ends (RACE), IbLCYe gene was cloned from sweetpotato cv. Nongdafu 14 with high carotenoid content. The 1 805 bp cDNA sequence of IbLCYe gene contained a 1 236 bp open reading frame (ORF) encoding a 411 amino acids polypeptide with a molecular weight of 47 kDa and an isoelectric point (pI) of 6.95. IbLCYe protein contained one potential lycopene ε-cyclase domain and one potential FAD (flavinadenine dinucleotide)/NAD(P) (nicotinamide adenine dinucleotide phosphate)-binding domain, indicating that this protein shares the typical characteristics of LCYe proteins. The gDNA of IbLCYe gene was 4 029 bp and deduced to contain 5 introns and 6 exons. Real-time quantitative PCR analysis revealed that the expression level of IbLCYe gene was significantly higher in the storage roots of Nongdafu 14 than those in the leaves and stems. Transgenic tobacco (cv. Wisconsin 38) expressing IbLCYe gene accumulated significantly more β-carotene compared to the untransformed control plants. These results showed that IbLCYe gene has an important function for the accumulation of carotenoids of sweetpotato.

The contents of carotenoids in the storage root of sweetpotato, Ipomoea batatas (L.) Lam. vary dramatically among different cultivars. However, so far little is known about the regulation of carotenoids synthesis in sweetpotato. In our laboratory, we identified a novel sweetpotato mutant, Nongdafu 14, which is a homogenous mutant derived from the wild type Kokei No. 14. The contents of carotenoids in the storage root of Nongdafu 14 were analyzed using high performance liquid chromatography (HPLC), and it was found that the amount of carotenoids, b-carotene, lutein and zeaxantion, three major types of carotenoids in sweetpotato storage roots, increased 2-26 folds in Nongdafu 14 compared to Kokei No. 14. Suppression subtractive hybridization (SSH) was used to identify genes that were differentially expressed in Nongdafu 14, and a differentially expressed cDNA library was constructed using the cDNA of Nongdafu 14 storage roots as tester and that of Kokei No. 14 storage roots as driver. Out of the 1 530 clones sequenced, we identified 292 nonredundant ESTs. GO and KEGG analyses of these differentially expressed ESTs indicated that diverse metabolism pathways were affected and candidate genes involved in regulation of carotenoids synthesis are suggested.

This research focuses on the impact of family’s human capital on social mobility in China’s rural community. Empirical research is conducted based on data from surveying a typical rural community in the past 20 yr. The study indicates that social mobility in rural area is active in the past 20 yr, and the human capital of family, represented by primary labor’s education level, has played an essential role in mobility of low social class. Meanwhile, socio-economic development and the change of supply and demand in labor market dims the signaling role of degree education, but the impact of occupational training is increasingly remarkable. Therefore, the change from sole degree education to multi-leveled education including occupational education and training is a main way for China’s rural families in low class to realize social mobility.

To elucidate the differential gene expression patterns in soybeans during infection by Phytophthora sojae, a cDNA libraryfor suppression subtractive hybridization (SSH) was constructed with cDNAs from soybean cultivar Suinong 10 treatedwith sterile distilled water as the driver and cDNAs from Suinong 10 inoculated with P. sojae as the tester. A total of 2 067recombinant colonies from the SSH library were randomly picked, amplified, and sequenced. After discarding 312 poorquality expressed sequence tags (EST), 1 755 high quality ESTs were assembled and edited to 1 384 tentatively uniquegenes (TUG), in which, 586 showed significant homology to known sequences, and 798 had low homology or no matchwith the known sequences. A cDNA microarray containing 307 singletons from the 586 TUGs and 222 singletons from the798 TUGs was developed to characterize differentially expressed cDNAs in the SSH library, and eight cDNAs wereidentified to be up-regulated after microarray analysis and then confirmed by real-time PCR. They were homologous to theprotein 10, and were also related to some proteins in disease resistance response, such as pathogen-related protein,phenylalanine ammonia-lyase, isoflavone reductase, WRKY transcription factor 31, major allergen Pru ar 1, and pleiotropicdrug resistance protein 12. Most of the up-regulated cDNAs encode enzymes of phytoalexin biosynthesis andpathogenesis-related proteins involved in plant disease resistance. Here, we fist reported the Pru ar 1 in soybeans. Thefindings of this research have contributed to better understanding of soybean resistance to P. sojae at the molecular level.

We investigated the size distribution of water-stable aggregates and the soil carbon, nitrogen and phosphorus concentration
over aggregate size fractions based on a long-term (1990-2006) fertilization experiment in a reddish paddy soil. The results
showed that the largest water-stable aggregate (WSA) (>5 mm) and the smallest WSA (<0.25 mm) took up the first largest
proportion (38.3%) and the second largest proportion (23.3%), respectively. Application of organic materials increased
the proportion of the large WSA (>2 mm) and decreased the proportion of the small WSA (<1 mm), resulting in an increase
in the mean weight diameter of WSA, whereas application of chemical fertilizer had little effect. Application of organic
materials, especially combined with chemical fertilizers, increased total carbon, nitrogen and phosphorus concentrations
in all sizes of WSA, and total carbon, nitrogen and phosphorus were prone to concentrate in the large WSA. Further more,
application of organic materials improved the supply effectiveness of available phosphorus, whereas had little influence
on the labile carbon in WSA. Application of chemical fertilizers improved concentrations of total and available phosphorus
in all sizes of WSA, whereas had little influence on total carbon and nitrogen contents. Economical fertilization model
maintained the soil fertility when compared with full dose of chemical fertilizers, indicating that using organic materials
could reduce chemical fertilizers by about one third.We investigated the size distribution of water-stable aggregates and the soil carbon, nitrogen and phosphorus concentration over aggregate size fractions based on a long-term (1990-2006) fertilization experiment in a reddish paddy soil. The results showed that the largest water-stable aggregate (WSA) (>5 mm) and the smallest WSA (<0.25 mm) took up the first largest proportion (38.3%) and the second largest proportion (23.3%), respectively. Application of organic materials increased the proportion of the large WSA (>2 mm) and decreased the proportion of the small WSA (<1 mm), resulting in an increase in the mean weight diameter of WSA, whereas application of chemical fertilizer had little effect. Application of organic materials, especially combined with chemical fertilizers, increased total carbon, nitrogen and phosphorus concentrations in all sizes of WSA, and total carbon, nitrogen and phosphorus were prone to concentrate in the large WSA. Further more, application of organic materials improved the supply effectiveness of available phosphorus, whereas had little influence on the labile carbon in WSA. Application of chemical fertilizers improved concentrations of total and available phosphorus in all sizes of WSA, whereas had little influence on total carbon and nitrogen contents. Economical fertilization model maintained the soil fertility when compared with full dose of chemical fertilizers, indicating that using organic materials could reduce chemical fertilizers by about one third.

To establish a suitable and effective protocol of protein extraction for two-dimensional gel electrophoresis (2-DE) analysis in kenaf leaf tissues, three extraction methods (trichloroacetic acid/acetone, urea/thiourea, and phenol extraction methods) were applied to the extraction of kenaf leaf protein. The results were compared in regard to protein extraction efficiency, sodiumdodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and 2-DE gels. Furthermore, the 2-DE system was optimized for four aspects: the pH range of IPG (immobilized pH gradient) stripes, sampling methods, sample volumes, and concentration of polyacrylamide gels. The data presented showed that the phenol extraction method is the best method to perform 2-DE analysis of kenaf leaf protein. The protein extracted from phenol extraction method reached the purity of (26.40±0.859)%, showed (25.67±1.53) protein bands in one dimension SDS-PAGE gels, and (1 374±54.44) protein spots on 2-DE gels. The research also indicates that kenaf leaf protein spots were distributed mainly within the pH range of 4-8. More clear background with a better distribution effect and many protein spots could be obtained on 2-DE gels under the conditions of active rehydration loading, 24 cm IPG strips (linear pH gradient of 4-7), 1.4 mg samples, and 12% SDS-PAGE gels.

Genotype imputation is essential for increasing marker density and maximizing the utility of existing SNP array data in animal breeding. Although a wide range of software is available for genotype imputation, a comprehensive benchmark in pigs is still lacking. In this study, we benchmarked 24 combinations of genotype imputation software for SNP arrays in pigs, comprising six independent pre-phasing software (fastPHASE, MaCH, BIMBAM, Eagle, SHAPEIT, Beagle) and four distinct imputation software (pbwt, Minimac, IMPUTE, Beagle), using 1,602 whole-genome sequencing (WGS) pigs from a multibreed pig genomics reference panel (PGRP) in PigGTEx. Our results indicated that the combination of Beagle for pre-phasing and Minimac for imputation achieves the highest imputation accuracy with a concordance of 0.983, especially for low-frequency SNPs (MAF<0.05). Finally, we proposed three recommended strategies: i) the combination of Beagle and Minimac is optimal for achieving the highest accuracy; ii) the combination of Beagle and Beagle is recognized for its convenience and relatively high accuracy despite it being memory-intensive; iii) the combination of Eagle and pbwt is feasible for its minimal computational cost with relatively high accuracy. This study provides valuable insights for implementing genotype imputation for pig SNP arrays toward sequence data and offers a basis for applications in livestock and poultry breeding.