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Gu W.,Guangdong Academy of Agricultural Sciences
Wei sheng wu xue bao = Acta microbiologica Sinica | Year: 2012

The aim of this study was to screen microorganisms that could degrade rice straw. We used selective medium to screen strains and determined straw fracture tension strength, weight loss, lignocellulose decomposition rate and extracellular enzyme activity as re-screening methods after 10 days shake flask culture. We isolated two antinomycetes (A3 and A6), the highest cellulose enzyme activity of holoenzyme, beta3-Glucosidase, endonuclease and exonclease for A3 were 12.84, 6.23, 24.56 and 14.00 U/mL, and for A6 12.85, 6.53, 17.80 and 18.80 U/mL. The hemicelluloses enzyme activity was 83.05 for A3 and 52.98 U/mL for A6. Both strains belonged to Streptomyces. With 10 days' treatment, inoculated straws showed a decrease of straw fracture tension strength by 62.67% (A3) and 66.67% (A6), while weight loss of straw was 31.50% (A3) and 35.83% (A6). A3's decomposition rate of cellulose, hemicellulose and lignin was 38.73% , 33.16% and 20.68% , and 47.69% , 28.64% and 22.59% for A6. Antinomycetes A3 and A6 could degrad cellulose, hemicellulose and lignin. Source

Li D.M.,Guangdong Academy of Agricultural Sciences
Genetics and molecular research : GMR | Year: 2012

NAC proteins, which are plant-specific transcription factors, have been identified to play important roles in plant response to stresses and in plant development. The full-length cDNAs that encode 2 putative NAC proteins, designated as MmATAF1 and MmNAP, respectively, were cloned from Mikania micrantha by rapid amplification of cDNA ends. The full-length cDNAs of MmATAF1 and MmNAP were 1329 and 1072 bp, respectively, and they encoded deduced proteins of 260- and 278-amino acid residues, respectively. The proteins MmATAF1 and MmNAP had a calculated molecular mass of 29.81 and 32.55 kDa and a theoretical isoelectric point of 7.08 and 9.00, respectively. Nucleotide sequence data indicated that both MmATAF1 and MmNAP contained 2 introns and 3 exons and that they shared a conserved genomic organization. Multiple sequence alignments showed that MmATAF1 showed high sequence identity with ATAF1 of Arabidopsis thaliana (61%) and that MmNAP showed high sequence identity with NAP of A. thaliana (67%) and CitNAC of Citrus sinensis Osbeck (62%). Phylogenetic analysis showed that the predicted MmATAF1 and MmNAP proteins were classified into the ATAF and NAP subgroups, respectively. Transient expression analysis of onion epidermal cells indicated nuclear localization of both MmATAF1-GFP and MmNAP-GFP fusion proteins. Semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) analysis indicated that MmATAF1 was expressed in all the tissues tested, but in varying abundance, while MmNAP was specifically expressed in stems, petioles, shoots, and leaves, but not in roots. The transcript levels of MmATAF1 and MmNAP in shoots and in infected stems were induced and strengthened by wounding, exogenous ZnSO(4), abscisic acid, salicylic acid, and Cuscuta campestris infection on the basis of semi-quantitative RT-PCR and real-time PCR analyses, respectively. Collectively, these results indicated that MmATAF1 and MmNAP, besides having roles in M. micrantha adaptation to C. campestris infection and abiotic stresses, also integrated signals derived from both C. campestris infection and abiotic stresses. Source

Luo C.,Guangdong Academy of Agricultural Sciences
BMC genomics | Year: 2013

Hyperpigmentation of the visceral peritoneum (HVP) has recently garnered much attention in the poultry industry because of the possible risk to the health of affected animals and the damage it causes to the appearance of commercial chicken carcasses. However, the heritable characters of HVP remain unclear. The objective of this study was to investigate the genetic parameters of HVP by genome-wide association study (GWAS) in chickens. HVP was found to be influenced by genetic factors, with a heritability score of 0.33. HVP had positive genetic correlations with growth and carcass traits, such as leg muscle weight (rg = 0.34), but had negative genetic correlations with immune traits, such as the antibody response to Newcastle disease virus (rg = -0.42). The GWAS for HVP using 39,833 single nucleotide polymorphisms indicated the genetic factors associated with HVP displayed an additive effect rather than a dominance effect. In addition, we determined that three genomic regions, involving the 50.5-54.0 Mb region of chicken (Gallus gallus) chromosome 1 (GGA1), the 58.5-60.5 Mb region of GGA1, and the 10.5-12.0 Mb region of GGA20, were strongly associated (P < 6.28 × 10-7) with HVP in chickens. Variants in these regions explained >50% of additive genetic variance for HVP. This study also confirmed that expression of BMP7, which codes for a bone morphogenetic protein and is located in one of the candidate regions, was significantly higher in the visceral peritoneum of Huiyang Beard chickens with HVP than in that of chickens without pigmentation (P < 0.05). HVP is a quantitative trait with moderate heritability. Genomic variants resulting in HVP were identified on GGA1 and GGA20, and expression of the BMP7 gene appears to be upregulated in HVP-affected chickens. Findings from this study should be used as a basis for further functional validation of candidate genes involved in HVP. Source

Wang S.,CAS Institute of Genetics and Developmental Biology | Wang S.,South China Agricultural University | Li S.,CAS Institute of Genetics and Developmental Biology | Liu Q.,CAS Institute of Genetics and Developmental Biology | And 9 more authors.
Nature Genetics | Year: 2015

The deployment of heterosis in the form of hybrid rice varieties has boosted grain yield, but grain quality improvement still remains a challenge. Here we show that a quantitative trait locus for rice grain quality, qGW7, reflects allelic variation of GW7, a gene encoding a TONNEAU1-recruiting motif protein with similarity to C-terminal motifs of the human centrosomal protein CAP350. Upregulation of GW7 expression was correlated with the production of more slender grains, as a result of increased cell division in the longitudinal direction and decreased cell division in the transverse direction. OsSPL16 (GW8), an SBP-domain transcription factor that regulates grain width, bound directly to the GW7 promoter and repressed its expression. The presence of a semidominant GW7 TFA allele from tropical japonica rice was associated with higher grain quality without the yield penalty imposed by the Basmati gw8 allele. Manipulation of the OsSPL16-GW7 module thus represents a new strategy to simultaneously improve rice yield and grain quality. © 2015 Nature America, Inc. Source

Huang J.-C.,CAS Kunming Institute of Botany | Zhong Y.-J.,University of Hong Kong | Zhong Y.-J.,Guangdong Academy of Agricultural Sciences | Liu J.,University of Hong Kong | And 2 more authors.
Metabolic Engineering | Year: 2013

Dietary carotenoids have been shown to be beneficial to health by decreasing the risk of many diseases. Attempts to enhance carotenoids in food crops have been successful although higher plants appear to resist big changes of carotenoid biosynthesis by metabolic engineering. Here we report the generation of a more nutritious tomato by modifying the intrinsic carotenes to astaxanthin, a high-value ketocarotenoid rarely found in plants. This was achieved by co-expression of the algal β-carotene ketolase from Chlamydomonas reinhardtii and β-carotene hydroxylase from Haematococcus pluvialis, a unique pair of enzymes identified to co-operate perfectly in converting β-carotene to astaxanthin by functional complementation in Escherichia coli. Expression of the two enzymes in tomato up-regulated most intrinsic carotenogenic genes, and efficiently directed carbon flux into carotenoids, leading to massive accumulations of mostly free astaxanthin in leaves (3.12. mg/g) but esterified astaxanthin in fruits (16.1. mg/g) and a 16-fold increase of total carotenoid capacity therein without affecting the plant normal growth and development. This study opened up the possibility of employing crop plants as green factories for economical production of astaxanthin. © 2013 Elsevier Inc. Source

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