Solanum tuberosum ZPR1 encodes a light-regulated nuclear DNA-binding protein adjusting the circadian expression of StBBX24 to light cycle

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Polyethylene/Polyamide Blends Made of Waste with Compatibilizer: Processing, Morphology, Rheological and Thermo-Mechanical Behavior

The aim of this study was to develop a polyethylene/polyamide (R-PE/R-PA) regranulated product made from post-consumer wastes grafted with polyethylene-graft-maleic anhydride (PE-g-MAH) by reactive extrusion in a twin-screw extruder equipped with an external mixing zone. The compatibility effect of PE-g-MAH used as a modifier in R-PE/R-PA blends was evaluated by means of differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA), while the analysis of the chemical structure of this blend was carried out by Fourier transform infrared spectroscopy (FT-IR). The thermal properties, complex viscosity, and selected usage properties of R-PE/R-PA blends compatibilized with PE-g-MAH, i.e., density and water absorption, were evaluated. The morphology of the blends with and without the compatibilizer was observed by scanning electron microscopy. The R-PE/R-PA/MAH blend shows heterogenic structure, which is a result of the chemical reaction in reactive extrusion between functional groups of PE-g-MAH used as modifier and the end groups of R-PA6. The results show that the R-PE/R-PA blend with increased PE-g-MAH content showed increased hardness, stiffness, and ultimate tensile strength due to the increased degree of crystallinity. The increase in crystallinity is proportional to the improvement of the mechanical properties. Moreover, it is shown that 1 wt.% PE-g-MAH added to the R-PE/R-PA waste blend increases the interfacial interactions and compatibility between R-PE and R-PA, resulting in decreased polyamide particle size. Finally, the results show that it is possible to produce good quality regranulated products with advantageous properties and structure from immiscible polymer waste for industrial applications

Genome-wide survey of B-box proteins in potato (<i>Solanum tuberosum</i>)—Identification, characterization and expression patterns during diurnal cycle, etiolation and de-etiolation

<div><p>Plant B-box domain proteins (BBX) mediate many light-influenced developmental processes including seedling photomorphogenesis, seed germination, shade avoidance and photoperiodic regulation of flowering. Despite the wide range of potential functions, the current knowledge regarding BBX proteins in major crop plants is scarce. In this study, we identify and characterize the <i>StBBX</i> gene family in potato, which is composed of 30 members, with regard to structural properties and expression profiles under diurnal cycle, etiolation and de-etiolations. Based on domain organization and phylogenetic relationships, <i>StBBX</i> genes have been classified into five groups. Using real-time quantitative PCR, we found that expression of most of them oscillates following a 24-h rhythm; however, large differences in expression profiles were observed between the genes regarding amplitude and position of the maximal and minimal expression levels in the day/night cycle. On the basis of the time-of-day/time-of-night, we distinguished three expression groups specifically expressed during the light and two during the dark phase. In addition, we showed that the expression of several <i>StBBX</i> genes is under the control of the circadian clock and that some others are specifically associated with the etiolation and de-etiolation conditions. Thus, we concluded that StBBX proteins are likely key players involved in the complex diurnal and circadian networks regulating plant development as a function of light conditions and day duration.</p></div

Phylogenetic analysis of the potato B-box family.

<p>Full-length proteins of the 30 B-box members were aligned using MUSCLE in MEGA 6.06 software with default parameters [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0177471#pone.0177471.ref049" target="_blank">49</a>]. The achieved alignment was used as a input to construct the phylogenetic tree with 1000 bootstrap replicates.</p

Diurnal and circadian regulation of <i>StBBX</i> family genes expression.

<p>Analysis of <i>StBBX</i> transcript abundances in 2-week-old phytotron-grown <i>S</i>. <i>tuberosum</i> plants under a 14-h photoperiod (solid blue line) and continuous light (dashed red line) for 42 h during the subjective light and dark phases. Samples were collected at the indicated time points. qRT-PCR was performed as described in Material and Methods. To determine statistical significance between the maximum and minimum levels of the corresponding transcripts oscillation of the <i>StBBX</i> genes, we applied the Student's T-test.</p

Classification of <i>StBBX</i> genes from <i>Solanum tuberosum</i>, cv. Desiree in terms of their expression in diurnal and circadian cycle and etiolation and de-etiolation conditions.

<p>Classification of <i>StBBX</i> genes from <i>Solanum tuberosum</i>, cv. Desiree in terms of their expression in diurnal and circadian cycle and etiolation and de-etiolation conditions.</p

Regulation of <i>StBBX</i> family genes expression during etiolation and de-etiolation.

<p>Analysis of <i>StBBX</i> transcript abundances in 2-week-old phytotron-grown <i>S</i>. <i>tuberosum</i> plants under a 14-h photoperiod—control plants (solid blue line) and a continuous dark followed by a 14-h photoperiod (black bold line). Samples were collected at the indicated time points. qRT-PCR was performed as described in Material and Methods.</p

Structural classification of the StBBX family proteins.

<p>The name and the length of corresponding StBBX protein and the position of characteristic B-box 1, B-box 2, CCT domains is shown on the right. The location and order of B-box 1, B-box 2 and CCT domains and VP motif within each protein is presented on the diagram.</p

Locations of 30 <i>BBX</i> genes on 12 potato chromosomes.

<p>The scale on the left is in megabases. Chromosome numbers are indicated at the top of each bar. The gene names on the left and the right side of each chromosome correspond to the approximate locations of each <i>BBX</i> gene. An additional copy of <i>StBBX*</i> gene identified using potato pseudomolecule database v 4.04 was marked in red.</p