Plant chlorophyll biosynthesis and chloroplast development are two complex processes that are regulated by exogenous and endogenous factors.  In this study, we identified OsDXR, a gene encoding a reductoisomerase that positively regulates chlorophyll biosynthesis and chloroplast development in rice.  OsDXR knock-out lines displayed the albino phenotype and could not complete the whole life cycle process.  OsDXR was highly expressed in rice leaves, and subcellular localization indicated that OsDXR is a chloroplast protein.  Many genes involved in chlorophyll biosynthesis and chloroplast development were differentially expressed in the OsDXR knock-out lines compared to the wild type.  Moreover, we found that the RNA editing efficiencies of ndhA-1019 and rpl2-1 were significantly reduced in the OsDXR knock-out lines.  Furthermore, OsDXR interacted with the RNA editing factor OsMORF1 in a yeast two-hybrid screen and bimolecular fluorescence complementation assay.  Finally, disruption of the plastidial 2-C-methyl-derythritol-4-phosphate pathway resulted in defects in chloroplast development and the RNA editing of chloroplast genes.

Carotenoids are involved in the formation of plant leaf color as well as photosystem photoprotection.  This study showed that blue light significantly induced up-regulation of the total carotenoid content in the inner leaves of orange-head Chinese cabbage (OHCC).  Furthermore, the transcriptomic analysis revealed that blue light treatment induced up-regulation of genes in photosynthesis (BrHY5-2, BrCOP1 and BrDET1) and the methylerythritol 4-phosphate pathways (BrGGPS, BrDXS and BrHDR) upstream of the carotenoid metabolic pathway.  Carotenoid metabolomic analysis revealed that the accumulation of several orange and red carotenoids (lycopene, zeaxanthin, β-carotene, lutein, and β-cryptoxanthin) after blue light treatment contributed to the deepening of the leaf coloration, suggesting that short-term blue light treatment could be used to boost nutritional quality.  The light signal gene BrHY5-2 participated in the blue light-induced transcriptional regulation of carotenoid biosynthesis in OHCC.  Overexpression of BrHY5-2 in Arabidopsis significantly increased the total carotenoid content and the sensitivity to blue light.  The above findings revealed new insights about blue-light-induced carotenoid synthesis and accumulation in OHCC lines.  They suggested a new engineering approach to increase the nutritional value of vegetables.

Follistatin (FST) is an important regulator of skeletal muscle growth and adipose deposition through its ability to bind to several members of the transforming growth factor-β (TGF-β) superfamily, and thus may be a good candidate for future animal breeding programs.  However, the molecular mechanisms underlying the phenotypic changes have yet to be clarified in pig.  We generated transgenic (TG) pigs that express human FST specifically in skeletal muscle tissues and characterized the phenotypic changes compared with the same tissues in wild-type pigs.  The TG pigs showed increased skeletal muscle growth, decreased adipose deposition, and improved metabolism status (P<0.05).  Transcriptome analysis detected important roles of the PIK3–AKT signaling pathway, calcium-mediated signaling pathway, and amino acid metabolism pathway in FST-induced skeletal muscle hypertrophy, and depot-specific oxidative metabolism changes in psoas major muscle.  Furthermore, the lipid metabolism-related process was changed in adipose tissue in the TG pigs.  Gene set enrichment analysis revealed that genes related to lipid synthesis, lipid catabolism, and lipid storage were down-regulated (P<0.01) in the TG pigs for subcutaneous fat, whereas genes related to lipid catabolism were significantly up-regulated (P<0.05) in the TG pigs for retroperitoneal fat compared with their expression levels in wild-type pigs.  In liver, genes related to the TGF-β signaling pathway were over-represented in the TG pigs, which is consistent with the inhibitory role of FST in regulating TGF-β signaling.  Together, these results provide new insights into the molecular mechanisms underlying the phenotypic changes in pig.

Pea aphid, Acyrthosiphon pisum, is a serious pest of many different leguminous plants, and it mainly relies on its odorant receptors (Ors) to discriminate among host species.  However, less is known about the role that Ors play in the host plant location.  In this study, we identified a novel conserved odorant receptor clade by phylogenetic analysis, and conducted the functional analysis of ApisOr23 in A. pisum.  The results showed that the homologous Ors from A. pisum, Aphis glycines and Aphis gossypii share 94.28% identity in amino acid sequences.  Moreover, conserved motifs were analyzed using the annotated homologous Or23 from eight aphid species, providing further proof of the high conservation level of the Or23 clade.  According to the tissue expression pattern analysis, ApisOr23 was mainly expressed in the antennae.  Further functional study using a heterologous Xenopus expression system revealed that ApisOr23 was tuned to five plant volatiles, namely trans-2-hexen-1-al, cis-2-hexen-1-ol, 1-heptanol, 4´-ethylacetophenone, and hexyl acetate.  Among them, trans-2-hexen-1-al, which is one of the main volatile organic compounds released from legume plants, activated the highest response of ApisOr23.  Our findings suggest that the conserved Or23 clade in most aphid species might play an important role in host plant detection.

Elevated activities of cytosolic fructose-1,6-bisphosphatase (cyFBPase) and sedoheptulose-1,7-bisphosphatase (SBPase) are associated with higher yields in plants.  In this study, the expression levels of the cyFBPase and SBPase genes were increased by overexpressing rape (Brassica napus) cDNA in tobacco (Nicotiana tabacum) plants.  The transgenic plants co-expressing cyFBPase and SBPase (TpFS), or expressing single cyFBPase (TpF) or SBPase (TpS) had 1.77-, 1.55-, 1.23-fold cyFBPase and 1.45-, 1.12-, 1.36-fold SBPase activities as compared to the wild-type (WT), respectively.  Photosynthesis rates of TpF, TpS and TpFS increased 4, 20 and 25% compared with WT plants.  The SBPase and cyFBPase positively regulated each other and functioned synergistically in transgenic tobacco plants.  In addition, the sucrose contents of the three transgenic plants were higher than that of WT plants.  The starch accumulation of the TpFS and TpS plants was improved by 53 and 37%, but slightly decreased in TpF plants.  Moreover, the transgenic tobacco plants harbouring SBPase and/or cyFBPase genes showed improvements in their growth, biomass, dry weight, plant height, stem diameter, leaf size, flower number, and pod weight.  In conclusion, co-expression of SBPase and cyFBPase may pave a new way for improving crop yield in agricultural applications.

Cotton is a globally important natural fiber and oilseed crop of crucial economic significance.  Molecular breeding has become a dominant method of cotton cultivation because it allows for a shorter breeding period and directional selection of high quality genes.  Patent data are key resources and are the core competitiveness of agricultural development, as the world’s largest and most reliable source of technical information.  However, little attention has been paid to patent analysis of cotton molecular breeding.  This study uses bibliometric analysis methodology and technical classification indexing to reveal global development trends of cotton molecular breeding, based on patents by retrieval methods and expert screening.  The annual number of patents, the life-cycle of patent-based technology, patent portfolios of primary countries, and main patentees, as well as technical distribution of patents, were analyzed in this study.  In addition, this study put emphasis on the comparative analysis of two important patentees through patent roadmaps based on the relationship among patent citations.  Finally, in order to understand the trend of new molecular breeding technology, patents related to clustered regularly interspaced short palindromic repeats (CRISPR), RNA interference (RNAi), and gene chip were also analyzed, all of which apply to cotton but also to other crops.  Results in this paper can provide references for cotton molecular breeding researchers and relevant management departments.

The germplasm resources for the S-type male sterility is rich in maize and it is resistant to Bipolaris maydis race T and CI, but the commercial application of S-type cytoplasmic male sterility (CMS-S) in maize hybrid industry is greatly compromised because of its common fertility instability. Currently, the existence of multiple minor effect loci in specific nuclear genetic backgrounds was considered as the molecular mechanism for this phenomenon. In the present study, we evaluated the fertility segregation of the different populations with the fertility instable material FIL-H in two environments of Beijing and Hainan, China. Our results indicated that the fertility instability of FIL-H was regulated by multiple genes, and the expression of these genes was sensitive to environmental factors. Using RNA sequencing (RNA-seq) technology, transcriptomes of the sterile plants and partially fertile plants resulted from the backcross of FIL-H×Jing 724 in Hainan were analyzed and 2 108 genes with different expression were identified, including 1 951 up-regulated and 157 down-regulated genes. The cluster analysis indicated that these differentially expressed genes (DEGs) might play roles in many biological processes, such as the energy production and conversion, carbohydrate metabolism and signal transduction. In addition, the pathway of the starch and sucrose metabolism was emphatically investigated to reveal the DEGs during the process of starch biosynthesis between sterile and partially fertile plants, which were related to the key catalytic enzymes, such as ADP-G pyrophosphorylase, starch synthase and starch branching enzyme. The up-regulation of these genes in the partially fertile plant may promote the starch accumulation in its pollen. Our data provide the important theoretical basis for the further exploration of the molecular mechanism for the fertility instability in CMS-S maize.

The supernumerary spikelets (SS) characters of tetraploid wheat (Triticum turgidum L.) resulting in more spikelets and kernels per spike, thus enhancing sink capacity may contribute to potential wheat yield improvement.  In order to investigate the effect of different SS types on agronomic characters and understand the genetic base of SS phenotype in tetraploid wheat, near isogenic lines (NILs), bh-50 with normal spikelets (NS), bh-51 with four-rowed spikelets (FRS), bh-52 with short-ramified spikelets (SRS), and bh-53 with long-ramified spikelets (LRS) in a Triticum durum cv. ZY1286 genetic background were developed by continuous backcrossing.  Agronomic characters showed that the SS phenotype lines, bh-51, bh-52 and bh-53 have significant increase in the number of spikelets and grains per spike compared with the NS phenotype line bh-50 (P<0.05), and bh-53 line showed much more increase than those of bh-51 and bh-52.  However, bh-53 had the lowest grain weight and the longest spike development stage than those of other spike phenotypes.  These results indicated that the different SS types have different effects on the agronomic and spike characters.  Genetic analysis through bh-50/bh-51 and bh-51/bh-53 F₂ populations showed that a recessive major gene controlled the spike architecture to transform from NS to FRS, and a dominant major gene determined the change of spike phenotype from FRS to RS.  DNA sequences of TtBH/WFZP ortholog on chromosome 2AS revealed that a single nucleotide polymorphism (SNP) substitution happened in the open reading frame (ORF) region of all the SS tetraploid wheat accessions, which may lead to the generation of lateral meristems between glume and lemma during the immature spike development.  While the fates of the lateral meristems, developing into lateral spikelets or branched spikelets, may be determined by another major gene.  Our results presented here may advance our understanding and knowledge of the genes and genetic pathways determining the spike architecture development in wheat.

The development of genetically modified crops requires new promoters and regulatory regions to achieve high gene expression and/or tissue-specific expression patterns in plants. To obtain promoter sequences of plants with new properties, we analyzed the expression traits of the cotton (Gossypium hirsutum) translation elongation factor 1A gene family. The results showed that the GhEF1A8 gene is highly expressed in different organs of cotton plants, and showed much higher transcript levels in stems and leaves. Its promoter (GhEF1A1.7) and the 5´ untranslated region (5´ UTR), comprising a regulatory region named PGhEF1A8, were isolated from cotton and studied in stably transformed tobacco plants. The regulatory region sequences were fused to the β-glucuronidase (GUS) reporter gene to characterize its expression pattern in tobacco. Histochemical and fluorometric GUS activity assays demonstrated that PGhEF1A8 could direct GUS gene expression in all tissues and organs in transgenic tobacco, including leaves, stems, flowers, and roots. The level of GUS activity in the leaves and stems was significantly higher than in cauliflower mosaic virus (CaMV) 35S promoter::GUS plants, but as same as CaMV 35S promoter::GUS plants in flower and root tissues. GUS expression levels decreased 2–10-fold when the 5´ UTR was absent from PGhEF1A8. Deletion analysis of the PGhEF1A8 sequence showed that the region −647 to −323 might possess negative elements that repress transgene expression in tobacco plants. The results suggested that the GhEF1A8 regulation region may represent a practical choice to direct high-level constitutive expression of transgenes and could be a valuable new tool in plant genetic engineering.

In order to understand the yield performance and nitrogen (N) response of hybrid rice under different ecological conditions in southern China, field experiments were conducted in Huaiji County of Guangdong Province, Binyang of Guangxi Zhuang Autonomous Region and Changsha City of Hunan Province, southern China in 2011 and 2012. Two hybrid (Liangyoupeijiu and Y-liangyou 1) and two inbred rice cultivars (Yuxiangyouzhan and Huanghuazhan) were grown under three N treatments (N1, 225 kg ha–1; N2, 112.5–176 kg ha–1; N3, 0 kg ha–1) in each location. Results showed that grain yield was higher in Changsha than in Huaiji and Binyang for both hybrid and inbred cultivars. The higher grain yield in Changsha was attributed to larger panicle size (spikelets per panicle) and higher biomass production. Consistently higher grain yield in hybrid than in inbred cultivars was observed in Changsha but not in Huaiji and Binyang. Higher grain weight and higher biomass production were responsible for the higher grain yield in hybrid than in inbred cultivars in Changsha. The better crop performance of rice (especially hybrid cultivars) in Changsha was associated with its temperature conditions and indigenous soil N. N2 had higher internal N use efficiency, recovery efficiency of applied N, agronomic N use efficiency, and partial factor productivity of applied N than N1 for both hybrid and inbred cultivars, while the difference in grain yield between N1 and N2 was relatively small. Our study suggests that whether hybrid rice can outyield inbred rice to some extent depends on the ecological conditions, and N use efficiency can be increased by using improved nitrogen management such as site-specific N management in both hybrid and inbred rice production.

Ulcerative colitis (UC) is a lifelong illness with profound emotional and social impacts, and could cause serious damage to large intestine, especially in colon. However, the pathogenesis of UC remained unclear. The present study attempts to find out the role of matrix metalloproteinases-7 (MMP-7) and lysozyme in the pathogenesis of UC through a mice model induced by dextran sulfate sodium (DSS). The UC model was evaluated both by disease activity index (DAI) and the intestinal histopathology. The results show that there is a high correlation between the DAI score and the pathological changes of colon. Interleukin-6 (IL-6) serum levels and large intestinal fluids levels in UC mice are always higher than that of the control groups, which might be associated with the degree of the inflammation damage in the colon. The change tendency of the MMP-7 mRNA and protein expressions are both up-regulated firstly and then down-regulated from 1 to 5 d in the colon, but only the MMP-7 protein is up-regulated at 7 d again. The up-regulated MMP-7 levels in the early stage of UC may play a protective role through the activated defensins, while the down-regulated levels in the mid-later stage of UC may be connected with the severe lesions in the colon. However, the up-regulated MMP-7 levels in the later stage of UC in the colon may also contribute to the tissue repair or be served as a marker to CRC (colorectal cancer). The distribution of lysozyme protein indicates that there may be Paneth-like cells in the colon. Both the changes of MMP-7 and lysozyme in the small intestine may play a protective role for the safe environment of the whole gut, especially to the colon of UC.

Sublethal effects of chlorantraniliprole to Helicoverpa armigera (Hübner) larvae were evaluated through exposure of third instar larvae to the insecticide incorporated into an artificial diet. When larvae were fed on the insecticide-containing diet for 7 d, the LC10, LC20, LC40, and LC50 values were 3.790, 7.977, 21.577, and 33.121 μg active ingredient L-1, respectively. Chlorantraniliprole at sublethal concentrations significantly reduced the larval body mass, emergence ratio, adult longevity and egg hatching rate in both the parental and offspring generations. The pupation and copulation rate in the parental generation and the pupal mass in the offspring also strongly decreased. Reproduction was seriously disturbed in both the parental and offspring groups even when only one of the partners was exposed to chlorantraniliprole at larval stages. However, at the lowest concentration of exposure (LC10), offspring fecundity was strongly reduced only when both partners were exposed. The net reproductive rate (R0), intrinsic rate of increase (rm), and gross reproduction rate (GRR) at LC20, LC40 concentrations were significantly lower than that of the control. Post-exposure effects also included an extended larval developmental time and increased male proportion in both generations. The doubling time (Dt) at LC20, LC40 concentrations as well as gross reproduction rate (GRR) at LC10 concentration were also significantly increased. Chlorantraniliprole might have significant effects on H. armigera population dynamics even at sublethal concentrations on both parental and offspring generations.

O3 is not only greenhouse gas but also a primary gaseous contaminant in the atmosphere. It has long-lasting effects on crop growth, yield and quality, and brings a series of ecological and environmental problems. A free-air controlled enrichment (FACE) system was applied to study the effect of elevated ozone concentration on activities of key enzymes of starch synthesis of Yangmai 16 in 2009-2010. The main-plot treatment had two levels of O3: ambient level (A-O3) and 50% higher than ambient level (E-O3). The main results were that accumulation rate of amylose, amylopectin and starch were represented in a single peak curve, and their content and accumulation amount rose gradually. The O3 elevation decreased the accumulation rate of amylose, amylopectin and starch amylase, reduced the accumulation amount of amylopectin and starch, and decreased the content of amylopectin and starch, but increased the content of amylose. With the increase of O3 concentration, the enzyme activity of grain granule-bound starch synthase (GBSS), soluble starch synthase (SSS) and starch branching enzyme (SBE) decreased after anthesis. The activities of GBSS and SSS had highly significant correlations with amylose, amylopectin and starch accumulation rate, and the activity of SBE had significant correlations with these items. So the O3 elevation decreased the activity of key enzymes of starch synthesis, which led to the variation of starch synthesis. Key words: