Rheological and Sensory Properties of Four Kinds of Dark Chocolates

The rheological properties of four kinds of chocolates (Dove, Leconte, Toblerone and Cote Dor) are determined by the rheometer of MCR101. The result shows that the melt samples have shear thinning behavior and thixotropic. The chocolates’ viscosities decrease with temperature increasing. The flow of melt chocolates follows Casson equation. The whole tanδ of chocolate is greater than 1, which indicates that the viscous composition is more than the elastic elements. The stress of Dove and Leconte changes rapidly compared with that of Toblerone and Cote Dor. Dove and Leconte have higher yield stress and anti-deformation ability than Toblerone and Cote Dor. The tanδ of Toblerone and Cote Dor is higher than that of the other two chocolates. This result shows that Toblerone and Cote Dor have a higher proportion of sticky ingredients. By the sensory properties, Dove and Leconte have higher overall acceptability.

Phytochrome B interacts with SWC6 and ARP6 to regulate H2A.Z deposition and photomorphogensis in Arabidopsis

Light serves as a crucial environmental cue which modulates plant growth and development, and which is controlled by multiple photoreceptors including the primary red light photoreceptor,phytochrome B(phyB). The signaling mechanism of phyB involves direct interactions with a group of basic helix-loop-helix(bHLH) transcription factors, PHYTOCHROME-INTERACTING FACTORS(PIFs), and the negative regulators of photomorphogenesis, COP1 and SPAs. H2 A.Z is an evolutionarily conserved H2 A variant which plays essential roles in transcriptional regulation. The replacement of H2 A with H2 A.Z is catalyzed by the SWR1 complex. Here, we show that the Pfr form of phyB physically interacts with the SWR1 complex subunits SWC6 and ARP6. phyB and ARP6 coregulate numerous genes in the same direction,some of which are associated with auxin biosynthesis and response including YUC9, which encodes a rate-limiting enzyme in the tryptophandependent auxin biosynthesis pathway. Moreover,phyB and HY5/HYH act to inhibit hypocotyl elongation partially through repression of auxin biosynthesis. Based on our findings and previous studies, we propose that phyB promotes H2 A.Z deposition at YUC9 to inhibit its expression through direct phyB-SWC6/ARP6 interactions,leading to repression of auxin biosynthesis, and thus inhibition of hypocotyl elongation in red light.

Effects of Materials of Cementless Femoral Stem on the Functional Adaptation of Bone

The objective of this paper is to identify the effects of materials of cementless femoral stem on the functional adaptive behaviors of bone. The remodeling behaviors of a two-dimensional simplified model of cementless hip prosthesis with stiff stem, flexible ＇iso-elastic＇ stem, one-dimensional Functionally Graded Material （FGM） stern and two-dimensional FGM stem for the period of four years after prosthesis replacement were quantified by incorporating the bone remodeling algorithm with finite element analysis. The distributions of bone density, von Mises stress, and interface shear stress were obtained. The results show that two-dimensional FGM stem may produce more mechanical stimuli and more uniform interface shear stress compared with the stems made of other materials, thus the host bone is well preserved. Accordingly, the two-dimensional FGM stem is an appropriate femoral implant from a biomechanical point of view. The numerical simulation in this paper can provide a quantitative computational paradigm for the changes of bone morphology caused by implants, which can help to improve the design of implant to reduce stress shielding and the risk of bone-prosthesis interface failure.

Lamin-like Proteins Negatively Regulate Plant Immunity through NAC WITH TRANSMEMBRANE MOTIF1-LIKE9 and NONEXPRESSOR OF PR 3ENES1 in Arabidopsis thaliana

Nuclear lamins are involved in multiple biological processes in metazoan cells. The proteins of the CROWDED NUCLEI （CRWN） family are considered lamin-like candidates in Arabidopsis, although the functions of these proteins are largely unknown. In this article we show that crwnl crwn2 double mutant displays an enhanced resistance against virulent bacterial pathogens, and both virulent bacteria and salicylic acid （SA） induce transcription of CRWN1 gene as well as proteasome-mediated degradation of CRWN1 protein. We also show that CRWN1 interacts with NAC WITH TRANSMEMBRANE MOTIF1 -LIKE9 （NTL9）, a NAC transcription factor involved in plant immunity. The interaction between CRWN1 and NTL9 enhances the binding of NTL9 to the promoter of the PATHOGENESIS-RELATED1 （PR1） gene, and inhibits PR1 expression. Further genetic experiments indicated that the defense-related phenotypes of crwnl crwn2 double mutant are dependent on NONEXPRESSOR OF PR GENES1 （NPR1）, a transcriptional cofactor of PRI. These findings revealed a regulatory network composed of lamin-like protein CRWN1, NTL9, and NPR1 for the regulation of PR1 expression.

Arabidopsis cryptochrome 1 promotes stomatal development through repression of AGB1 inhibition of SPEECHLESS DNA-binding activity

Cryptochromes are blue light photoreceptors that mediate various light responses in plants and mammals. The heterotrimeric G-protein is known to regulate various physiological processes in plants and mammals. In Arabidopsis, cryptochrome 1(CRY1) and the G-protein β subunit AGB1 act antagonistically to regulate stomatal development.The molecular mechanism by which CRY1 and AGB1 regulate this process remains unknown.Here, we show that Arabidopsis CRY1 acts partially through AGB1, and AGB1 acts through SPEECHLESS(SPCH), a master transcription factor that drives stomatal initiation and proliferation, to regulate stomatal development. We demonstrate that AGB1 physically interacts with SPCH to block the b HLH DNA-binding domain of SPCH and inhibit its DNA-binding activity. Moreover, we demonstrate that photoexcited CRY1 represses the interaction of AGB1 with SPCH to release AGB1 inhibition of SPCH DNA-binding activity, leading to the expression of SPCH-target genes promoting stomatal development. Taken together, our results suggest that the mechanism by which CRY1 promotes stomatal development involves positive regulation of the DNA-binding activity of SPCH mediated by CRY1 inhibition of the AGB1-SPCH interaction. We propose that the antagonistic regulation of SPCH DNA-binding activity by CRY1 and AGB1 may allow plants to balance light and G-protein signaling and optimize stomatal density and pattern.

PIFs interact with SWI2/SNF2-related 1 complex subunit 6 to regulate H2A.Z deposition and photomorphogenesis in Arabidopsis

Light is an essential environmental signal perceived by a broad range of photoreceptors in plants. Among them, the red/far-red light receptor phytochromes function to promote photomorphogenesis, which is critical to the survival of seedlings after seeds germination. The basic-helix-loop-helix transcription factors phytochrome-interacting factors (PIFs) are the pivotal direct downstream components of phytochromes. H2A.Z is a highly conserved histone variant regulating gene transcription, and its incorporation into nucleosomes is catalyzed by SWI2/SNF2-related 1 complex, in which SWI2/SNF2-related 1 complex subunit 6 (SWC6) and actin-related protein 6 (ARP6) serve as core subunits. Here, we show that PIFs physically interact with SWC6 in vitro and in vivo, leading to the disassociation of HY5 from SWC6. SWC6 and ARP6 regulate hypocotyl elongation partly through PIFs in red light. PIFs and SWC6 coregulate the expression of auxin-responsive genes such as IAA6, IAA19, IAA20, and IAA29 and repress H2A.Z deposition at IAA6 and IAA19 in red light. Based on previous studies and our findings, we propose that PIFs inhibit photomorphogenesis, at least in part, through repression of H2A.Z deposition at auxin-responsive genes mediated by the interactions of PIFs with SWC6 and promotion of their expression in red light.

The involvement of the N-terminal PHR domain of Arabidopsis cryptochromes in mediating light signaling

Light is a key environmental cue that fundamentally regulates all aspects of plant growth and development,which is mediated by the multiple photoreceptors including the blue light photoreceptors cryptochromes(CRYs).In Arabidopsis,there are two well-characterized homologous CRYs,CRY1 and CRY2.Whereas CRYs are flavoproteins,they lack photolyase activity and are characterized by an Nterminal photolyase-homologous region(PHR)domain and a C-terminal extension domain.It has been established that the C-terminal extension domain of CRYs is involved in mediating light signaling through direct interactions with the master negative regulator of photomorphogenesis,COP1.Recent studies have revealed that the N-terminal PHR domain of CRYs is also involved in mediating light signaling.In this review,we mainly summarize and discuss the recent advances in CRYs signaling mediated by the N-terminal PHR domain,which involves the N-terminal PHR domain-mediated dimerization/oligomerization of CRYs and physical interactions with the pivotal transcription regulators in light and phytohormone signaling.