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

International audienc

Expression and characterization of a barley phosphatidylinositol transfer protein structurally homologous to the yeast Sec14p protein

International audienc

Expression of SK3-type dehydrin in transporting organs is associated with cold acclimation in Solanum species

International audienc

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

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

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