Genome-Wide Analyses of SlFWL Family Genes and Their Expression Profiles under Cold, Heat, Salt and Drought Stress in Tomato.

PLAC8 is a cysteine-rich protein that serves as a central mediator of tumor evolution in mammals. PLAC8 motif-containing proteins widely distribute in fungi, algae, higher plants and animals that have been described to be implicated in fruit size, cell number and the transport of heavy metals such as cadmium or zinc. In tomatoes, FW2.2 is a PLAC8 motif-containing gene that negatively controls fruit size by regulating cell division and expansion in the carpel ovary during fruit development. However, despite FW2.2, other FWL (FW2.2-Like) genes in tomatoes have not been investigated. In this study, we identified the 21 SlFWL genes, including FW2.2, examined their expression profiles under various abiotic adversity-related conditions. The SlFWL gene structures and motif compositions are conserved, indicating that tomato SlFWL genes may have similar roles. Cis-acting element analysis revealed that the SlFWL genes may participate in light and abiotic stress responses, and they also interacted with a variety of phytohormone-responsive proteins and plant development elements. Phylogenetic analyses were performed on five additional plant species, including Arabidopsis, pepper, soybean, rice and maize, these genes were classified into five subfamilies. Based on the results of collinearity analyses, the SlFWL genes have a tighter homologous evolutionary relationship with soybean, and these orthologous FWL gene pairs might have the common ancestor. Expression profiling of SlFWL genes show that they were all responsive to abiotic stresses, each subgroup of genes exhibited a different expression trend. Our findings provide a strong foundation for investigating the function and abiotic stress responses of the SlFWL family genes.

Comparisons of prebiotic activity of polysaccharides from shoot residues of bamboo (Chimonobambusa quadrangularis) via different ethanol concentrations.

Three polysaccharide fractions from bamboo shoot (Chimonobambusa quadrangularis), CPS70, CPS75, and CPS80, were prepared using a final ethanol concentration of 70%, 75%, and 80% in the precipitation process. In vitro digestibility and the prebiotic activity of CPS70, CPS75, and CPS80 were evaluated and compared. The results indicated that all three of the CPS fractions exhibit a high degree of nondigestibility to human gastric juice (>98.5%) or α-amylase hydrolysis (>94.5%). Compared with the blank control, the three CPS fractions could not only significantly (p < .05) stimulate the proliferation of B. adolescentis, B. infantis, B. bifidum, and L. acidophilus, but also significantly (p < .05) enhance the production of lactic, acetic, propionic, and butyric acids when these polysaccharides were added as alternative carbon sources to glucose during the in vitro fermentation of four probiotics. Furthermore, when comparing the three CPS fractions, CPS75 displayed the strongest prebiotic potential, as this polysaccharide had the strongest effect on the proliferation of probiotic bacteria as well as the greatest effect on SCFAs production. These results demonstrated that the concentration of ethanol used during the precipitation process has a significant impact on the prebiotic activity of CPS. PRACTICAL APPLICATIONS: Ethanol precipitation is the first step when extracting polysaccharides from aqueous extracts as it is simple, rapid, and easy to carry out. This study focuses on how different concentrations of ethanol used in the precipitation process affect the prebiotic potential of bamboo shoot (Chimonobambusa quadrangularis) polysaccharides (CPS). The result indicated that the concentration of ethanol used during the precipitation process has a significant impact on the prebiotic activity of CPS. To our knowledge, it is the first to evaluate the effects of the concentration of ethanol during the process of precipitation on prebiotic potential of polysaccharides, which can subsequently be applied to the optimization of ethanol concentration when precipitating natural polysaccharides for the purpose of in vitro fermentation.

Adlay starch-gluten composite gel: Effects of adlay starch on rheological and structural properties of gluten gel to molecular and physico-chemical characteristics.

Effects of adlay starch on the rheological and conformational changes in wheat gluten gel were investigated in this study. Rheological measurement showed that adlay starch-gluten composite gels exhibited higher storage modulus G' and loss modulus G″ compared with pure gluten gels. This result was also confirmed through morphological analysis. As the addition of adlay starch increased from 0% to 40%, the surface hydrophobicity of gluten protein gel decreased from 16,660 to 11,931 and the free thiol content increased from 3.11 to 4.30 µmol/g. In addition, the ß-sheet structure in the gluten protein gel increased at the expense of the α-helical structure with increasing adlay starch fraction. This study revealed that besides acting as an inert filler, adlay starch could participate in hydrogen bonding and induce the enhancement of hydrophobic interaction to modify gluten protein association, altering the rheological and structural properties of gluten protein gels.

Comparison of different extraction methods for polysaccharides from bamboo shoots (Chimonobambusa quadrangularis) processing by-products.

The aim of this study was to evaluate the influences of extraction methods on the yield, chemical structure and antioxidant activity of polysaccharides from bamboo shoots (Chimonobambusa quadrangularis) processing by-products (CPS). CPSs were extracted by using five methods including hot water extraction (HWE), accelerated solvent extraction (ASE), ultrasonic-assisted extraction (UAE), microwave-assisted extraction (MAE) and enzyme-assisted extraction (EAE). The experimental results showed that the uronic acid contents, monosaccharide contents, molecular weights and antioxidant activities of the five CPSs were significantly different. CPS extracted using ASE method (ASE-CPS) possessed the highest extraction yield (9.94%), the highest medium-high-molecular-weight value (136.07 kDa) and notable antioxidant ability. UAE-CPS had the highest uronic acid (9.42%) and the lowest medium-high-molecular weight value (117.49 kDa), and its antioxidant activity was the best. Based on the correlation analysis, the higher uronic acid content, smaller molecular weight, and lower content of monosaccharide composition of glucose for the CPS-UAE might contribute to its higher antioxidant activity. From an industrial viewpoint, ASE technique could be a promising and alternative way to extract CPS due to its high yield, notable antioxidant activity, and convenient industrialization.

Identification of a cytochrome P450 CYP6AB60 gene associated with tolerance to multi-plant allelochemicals from a polyphagous caterpillar tobacco cutworm (Spodoptera litura).

Generalist phytophagous insects adapt to adventurous chemical environment in a wide variety of host plants by extraordinary detoxifying metabolic abilities. However, how polyphagous insect cope with the diversity of plant defenses remains largely unknown and only a few counter-defense genes detoxifying a wide range of toxic secondary metabolites have been well characterized. Here, we identify a cytochrome P450 gene (CYP6AB60) from tobacco cutworm (Spodoptera litura) in response to three different plant's defense metabolites. After being exposed to artificial diet supplemented with coumarin (COU), xanthotoxin (XAN) or tomatine (TOM), activities of P450 and CYP6AB60 transcript levels in both midgut and fat body tissues were significantly increased. Developmental expression analysis revealed that CYP6AB60 was expressed highly during the larval stages, and tissue distribution analysis showed that CYP6AB60 was expressed extremely high in the midgut, which correspond to the physiological role of CYP6AB60 from S. litura larvae in response to plant allelochemicals. Furthermore, when larvae are injected with double-stranded RNA (dsRNA) specific to CYP6AB60, levels of this transcript in the midgut and fatbody decrease and the negative effect of plant's defense metabolites on larval growth is magnified. These data demonstrate that the generalist insect S. litura might take advantage of an individual detoxificative gene CYP6AB60 to toxic secondary metabolites from different host plants. The CYP6AB60 can be a potential gene to carry out RNAi-mediated crop protection against the major polyphagous pest S. litura in the future.

Polysaccharides obtained from bamboo shoots (Chimonobambusa quadrangularis) processing by-products: New insight into ethanol precipitation and characterization.

Chimonobambusa quadrangularis polysaccharides (CPS) were extracted by ultrasonic-assisted extraction from bamboo shoots (C. quadrangularis) processing by-products. Three polysaccharide fractions, CPS70, CPS75 and CPS80, were obtained by precipitation at final ethanol concentrations of 70%, 75% and 80%, respectively. The physicochemical characterization and chemical antioxidant activities of the three polysaccharide fractions were compared on the basis of HPLC, FT-IR, XRD, TGA, and antioxidant measurements in vitro. The results suggested that ethanol concentrations used for precipitation of CPS can affect its physicochemical and associated functional properties, and antioxidant activities. Compared with CPS70 and CPS80, CPS75 had lower glucose content, higher total sugar content, and higher protein and uronic acid contents. The CPS70 and CPS80 were composed of Man, Rha, GlcA, Glc, Gal, Xyl and Ara, but none of them were found to contain GalA. In contrast, CPS75 consisted of Man, Rha, GlcA, GalA, Glc, Gal, Xyl and Ara. CPS75 had the lowest medium-high-molecular-weight value (116.53-118.18kDa) and the highest medium-low-molecular-weight value (21.30-22.68kDa). Meanwhile, CPS75 exhibited better functional properties including the repose angle, swelling capacity (SC), water retention capacity (WRC), and oil retention capacity (ORC). Moreover, CPS75 possessed higher scavenging capacities on DPPH, hydroxyl and ABTS radicals, higher oxygen radical absorbance capacity (OARC), higher metal chelating activity, and more significant reducing power. According to the results above, a final ethanol concentration of 75% could be chose to precipitate polysaccharides from bamboo shoots (C. quadrangularis) processing by-products. In summary, it is strongly recommended that the ethanol concentration employed in precipitation of natural polysaccharides could be optimized in advance.

Extraction, characterization and antioxidant activity of water-soluble polysaccharides from Tuber huidongense.

Single-factor experiment and Box-Behnken design were employed to optimize the ultrasonic-assisted extraction (UAE) of water-soluble polysaccharides from Chinese truffle Tuber huidongense (THWP). The optimal extraction conditions with an extraction yield of 7.17±0.22% crude THWP were determined as follows: ultrasonic power 99.65W, extraction time 40.39min, ratio of water to raw material 24.65mL/g, and extraction temperature 70.1°C. Two purified fractions, THWP-1 and THWP-2 with molecular weights of 128kDa and 729kDa, respectively, were obtained from crude THWP by Cellulose DEAE-52 and Sephadex G-100 chromatography. Monosaccharide component analysis by high performance liquid chromatography (HPLC) indicated that THWP-1 was composed of Glc, Man, and Gal with their corresponding mole percentages of 60.56%, 20.12% and 19.32%, respectively and that THWP-2 contained only Glc. Evaluation of the antioxidant activity in vitro suggested that THWP-1 and THWP-2 had effective scavenging activity of 2,2'-azinobis-(3-ethylbenzothiazolin-6-sulfonicacid) (ABST), hydroxyl and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. Accordingly, the polysaccharides from Chinese truffle might serve as a natural antioxidant in functional foods.