Natural products have long been a crucial source of, or provided inspiration for new agrochemical discovery.  Naturally occurring 18β-glycyrrhetinic acid shows broad-spectrum bioactivities and is a potential skeleton for novel drug discovery.  To extend the utility of 18β-glycyrrhetinic acid for agricultural uses, a series of novel 18β-glycyrrhetinic acid amide derivatives were prepared and evaluated for their antibacterial potency.  Notably, compound 5k showed good antibacterial activity in vitro against Xanthomonas oryzae pv. oryzae (Xoo, EC₅₀=3.64 mg L^–1), and excellent protective activity (54.68%) against Xoo in vivo.  Compound 5k induced excessive production and accumulation of reactive oxygen species in the tested pathogens, resulting in damaging the bacterial cell envelope.  More interestingly, compound 5k could increase the activities of plant defense enzymes including catalase, superoxide dismutase, peroxidase, and phenylalanine ammonia lyase.  Taken together, these enjoyable results suggested that designed compounds derived from 18β-glycyrrhetinic acid showed potential for controlling intractable plant bacterial diseases by disturbing the balance of the phytopathogen’s redox system and activating the plant defense system

Milling and appearance quality are important contributors to rice grain quality.  Abundant genetic diversity and a suitable environment are crucial for rice improvement.  In this study, we investigated the milling and appearance quality-related traits in a panel of 200 japonica rice cultivars selected from Liaoning, Jilin and Heilongjiang provinces in Northeast China.  Pedigree assessment and genetic diversity analysis indicated that cultivars from Jilin harbored the highest genetic diversity among the three geographic regions.  An evaluation of grain quality indicated that cultivars from Liaoning showed superior milling quality, whereas cultivars from Heilongjiang tended to exhibit superior appearance quality.  Single- and multi-locus genome-wide association studies (GWAS) were conducted to identify loci associated with milling and appearance quality-related traits.  Ninety-nine significant single-nucleotide polymorphisms (SNPs) were detected.  Three common SNPs were detected using the mixed linear model (MLM), mrMLM, and FASTmrMLM methods.  Linkage disequilibrium decay was estimated and indicated three candidate regions (qBRR-1, qBRR-9 and qDEC-3) for further candidate gene analysis.  More than 300 genes were located in these candidate regions.  Gene Ontology (GO) analysis was performed to discover the potential candidate genes.  Genetic diversity analysis of the candidate regions revealed that qBRR-9 may have been subject to strong selection during breeding.  These results provide information that will be valuable for the improvement of grain quality in rice breeding.

Close planting of dwarf varieties is currently the main cultivation direction for pear trees, and the screening of excellent dwarf varieties is an important goal for breeders.  In this study, the dwarfing pear variety ‘601D’ and its vigorous mutant ‘601T’ were used to show their biological characteristics and further explore the dwarfing mechanism in ‘601D’.  The biological characteristics showed that ‘601D’ had a shorter internode length, a shorter and more compact tree body, thicker and broader leaves, lower stomata density, larger stomata size (dimension), and higher photosynthetic capacity.  The biological characteristics of ‘601T’ showed notable contrasts.  The results of endogenous hormone tests indicated that the contents of abscisic acid (ABA), ABA-glucosyl ester, and GA4 were higher in ‘601D’, but the trans-zeatin content was lower.  By transcriptomic analysis, significant differences were found in the biosynthetic and metabolic pathways of ABA.  Related transcription factors such as bHLH, WRKY, and homeobox also participated in the regulation of plant dwarfing.  We therefore examined three hormones with obvious differences with ‘601T’, and found that only ABA could induce ‘601T’ to return to a dwarfing plant phenotype.  Therefore, we conclude that the dwarfing of ‘601D’ is caused by an excessive accumulation of ABA.  This study provides a new theoretical basis for breeding dwarf varieties.

Fat is an indispensable nutrient and basic metabolite for sustaining life, and milk is particularly rich in fatty acids, including a variety of saturated and unsaturated fatty acids.  MicroRNA (miRNA) and mRNA play an important role in the regulation of milk fat metabolism in mammary gland tissue.  It has been shown that lipid metabolism has a complex transcriptional regulation, but the mechanism by which milk fat synthesis is regulated through miRNA–mRNA interactions is poorly understood.  In this study, we performed transcriptome sequencing with bovine mammary gland tissue in the late lactation (270 and 315 days after parturition) to identify the key gene that regulating milk fat metabolism.  A total of 1 207 differentially coexpressed genes were selected, 828 upregulated genes and 379 downregulated genes were identified.  The transforming growth factor alpha (TGFA) gene was selected as the target gene, and luciferase reporter assay, Western blotting and qRT-PCR were used for further study.  The results demonstrated that miR-140 was an upstream regulator of TGFA, and miR-140 could inhibit (P<0.01) unsaturated fatty acid and triglyceride (TAGs) production in bovine mammary epithelial cells (BMECs).  In contrast, TGFA promoted (P<0.01) unsaturated fatty acid and TAG production.  Rescue experiments further indicated the miR-140/TGFA regulatory mechanism.  Taken together, these results suggest that the miR-140/TGFA pathway can inhibit (P<0.01) milk fat metabolism and improve milk quality by genetic means.

The total phenolic and flavonoid contents in the fruit tissues (peels, pulp residues, seeds, and juices) of 19 citrus genotypes belonged to Citrus reticulata Blanco were evaluated and their antioxidant capacity was tested by 2,2-diphenyl-1-picrylhydrazyl radicals (DPPH) method and 2,2´-azino-bis(3-ethylbenzthiozoline-6)-sulphonic acid (ABTS) method.  The total phenolic and flavonoid contents, and their antioxidant capacity varied in different citrus fruit tissues.  Generally, the peel had both the highest average of total phenolics (27.18 mg gallic acid equivalent (GAE) g^–1 DW) and total flavonoids (38.97 mg rutin equivalent (RE) g^–1 DW).  The highest antioxidant capacity was also the average of DPPH value (21.92 mg vitamin C equivalent antioxidant capacity (VCEAC) g^–1 DW) and average of ABTS value (78.70 mg VCEAC g^–1 DW) in peel.  The correlation coefficient between the total phenolics and their antioxidant capacity of different citrus fruits tissues ranged from 0.079 to 0.792, and from –0.150 to 0.664 for the total flavonoids.  The antioxidant capacity of fruit tissues were correlated with the total phenoilc content and flavonoid content except in case of the peel.  In addition, the total phenolic content and antioxidant capacity varied in different citrus genotypes.  Manju and Karamandarin were better genotypes with higher antioxidation and the phenolic content, however Shagan was the poorest genotype with lower antioxidation and the phenolic content.

Infection by hepatitis B virus (HBV) results in acute and chronic liver damages in humans. Liver products of broilers as a primary food consumed in our daily life have a close connection with public health. The prevalence of the virus in livers and serum of broilers is of great significance, owning to the potential transmission between chickens and humans. Liver tissues and serum samples were tested to investigate the prevalence of hepatitis B virus infection in slaughtered broilers, for expression of HBV antigens and antibodies. The distribution and positive rate of hepatitis B surface antigen (HBsAg), hepatitis B core antigen (HBcAg) and hepatitis B e antigen (HBeAg) in liver samples were examined using immunohistochemistry. HBsAg was mainly located in the cytoplasm of hepatocytes with a positivity of 81.61% whereas HBeAg and HBcAg were primarily located in the nucleus of hepatocytes with a positivity of 40.13 and 49.10%, respectively. Enzyme-linked immunosorbent assay (ELISA) analysis of serum for HBV serological markers demonstrated a high prevalence of hepatiits B surface antibody (HBsAb, 54.91%) and hepatitis B core antibody (HBcAb, 27.68%), whereas HBeAb, HBsAg and HBeAg were rarely detectable. Classic hepatitis pathological changes, including swollen hepatocytes, focal parenchymal necrosis, lymphocytic infiltration and hyperplasia of fibrous connective tissues were observed using histopathological analysis. Some of the liver samples were found positive for HBV DNA using nested PCR. Sequence comparison confirmed that all sequences shared 97.5–99.3% identity with human HBV strains. These results demonstrated the existence of HBV in livers and serums of broilers. Animals or animal products contaminated with HBV could raise an important public health concern over food safety and zoonotic risk.

The objective of this study was to determine the morphology mechanism of nitrogen (N) fertilizer rates and ratio on lodging resistance through analying its effects among lodging index (LI), lodging-related morphological traits and physical strength in basal internodes by comparing japonica and indica super rice cultivars. Field experiments, with three nitrogen levels (0, 150 and 300 kg ha-1) and two ratios of basal to topdressing (8:2 and 5:5) with two super rice cultivars (Yliangyou 2 and Wuyunjing 23), were conducted in the Baolin Farm, Danyang Country, Jiangsu Province, China, in 2011 and 2012. Effects of N fertilizer rates and ratios on morphology of whole plant, morphology traits in basal internodes and culm’s physical strength parameters were investigated at 20 d after full heading stage. LI of Yliangyou 2 was significant greater than that of Wuyunjing 23 due to larger bending moment by whole plant (WP) with higher plant height and gravity center height. With higher volume of N fertilizer, LI of two super rice cultivars was increased conspicuously. However, no significant effect was detected with increase of panicle fertilizer ratio. The size of breaking strength (M) in basal internodes was the key factor determining LI among N fertilizer treatments. Correlation analysis revealed that M value was positively related bending stress (BS) of Wuyunjing 23 and section modulus (Z) of Yliangyou 2, respectively. The higher N fertilizer levels induced reduction of BS of Wuyunjing 23 due to weak culm and leaf sheath plumpness status and reduced Z of Yliangyou 2 owning to small diameter and culm wall thickness, consequently, influencing their M indirectly. These results suggested that breaking strength was the key factor influencing LI with increase of N fertilizer levels. However, the lodging-related morphology mechanism was different with genotypes. Culm wall thickness and diameter in basal internodes of indica super rice and culm and leaf sheath plumpness status of japonica super rice influenced breaking strength, as well as lodging index, respectively.

Reducing dietary cation-anion difference (DCAD) has been proved an effective way to prevent milk fever in dairy cows. Based on the similar physiological gastro-intestinal tract anatomy and metabolic process between female goats and dairy cows, this study was conducted to evaluate the effects of varying DCAD on fluid acid-base status, plasma minerals concentration and anti-oxidative stress capacity of female goats. Urinary pH, plasma Ca, P and Mg; and anti-oxidative stress indices of total superoxide dismutase (T-SOD), hydrogen peroxide (H2O2), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) were determined to evaluate the effect. Forty-eight Guizhou black female goats ((15±1.9) mon of old, (22.3±3.75) kg of BW) were randomly allocated to 4 blocks of 12 goats each and were fed 1 of 4 diets differed in DCAD level (calculated as Na+K-Cl-S, mEq kg-1 DM). Levels of DCAD were preliminarily designed to be control (+150 mEq kg-1 DM, CON), high DCAD (+300 mEq kg-1 DM, HD), low DCAD (0 mEq kg-1 DM, LD) and negative DCAD (-150 mEq kg-1 DM, ND), respectively. A commercial anionic salts (Animate) and sodium bicarbonate (NaHCO3) were supplemented to reduce and increase DCAD level, respectively. There was no difference in dry matter intake for 4 groups of goats. Urine pH was aggressively decreased (P<0.0001) with reduced DCAD and there was a strong association between DCAD and urine pH (R2=0.793, P<0.0001). Compared with CON and HD feeding of LD and ND resulted in greater (P<0.05) plasma Ca concentration. Plasma P level was increased (P<0.05) when anionic salts were supplemented. The DCAD alteration did not affected (P>0.05) plasma Mg level. There was no significant (P>0.05) difference in plasma GSH-Px activity and H2O2, but anionic salts supplementation in LD and ND significantly increased (P<0.05) plasma T-SOD activity and tended to reduce MDA (P<0.1) over HD and CON. Results from this study indicated that reducing DCAD could decrease urine pH and increase plasma Ca concentration of female goats. Additionally, reducing DCAD was helpful to enhance anti-oxidative stress capability of female goats.

Carbohydrate partitioning from source to sink tissues is critical for plant growth and development. However, in maize (Zea mays L.), the molecular mechanisms of callose synthase gene regulating this process have seldom been reported.  Here, we show that the mutation of maize callose synthase12 (ZmCals12) caused increased accumulation of carbohydrate in the photosynthetic leaves but reduced carbohydrate content in sink tissues, which led to plant dwarfing and male sterile.  Histochemical GUS activity assay and mRNA in situ hybridization (ISH) indicated that ZmCals12 was mainly expressed in the vascular transport system.  Loss-of-function of ZmCals12 reduced callose synthase activity and callose deposition in plasmodesmatas (PDs) and around phloem cells (PCs) of vascular bundle.  The drop-and-see (DANS) assay revealed that the PD permeability in the photosynthetic cells and the transport competence of leaf veins were reduced in the Zmcals12 mutants, which led to the reduced symplastic transport.  Paraffin section experiment revealed that less-developed vascular cells (VCs) in the Zmcals12 mutants potentially disturbed sugar transport, thus resulting in the pleiotropic phenotype of the Zmcals12 mutants.  In addition, the impaired sugar transport hindered the internode development by inhibiting auxin (IAA) biosynthesis and signaling in the Zmcals12 mutant.  Collectively, our results provide insights into the mechanism of ZmCals12-mediated callose deposition and symplastic transport governing maize growth and development.