An Update to the TraVA Database: Time Series of Capsella bursa-pastoris Shoot Apical Meristems during Transition to Flowering

Transition to flowering is a crucial part of plant life directly affecting the fitness of a plant. Time series of transcriptomes is a useful tool for the investigation of process dynamics and can be used for the identification of novel genes and gene networks involved in the process. We present a detailed time series of polyploid Capsella bursa-pastoris shoot apical meristems created with RNA-seq. The time series covers transition to flowering and can be used for thorough analysis of the process. To make the data easy to access, we uploaded them in our database Transcriptome Variation Analysis (TraVA), which provides a convenient depiction of the gene expression profiles, the differential expression analysis between the homeologs and quick data extraction.

POLYPLOIDY INDUCED BY COLCHICINE IN Robinia pseudoacacia L. AND IT'S EFFECTS ON MORPHOLOGICAL, PHYSIOLOGICAL AND ANATOMICAL SEEDLING TRAITS

This study was aimed to induce and produce a polyploidy Robinia pseudoacacia seedling by different concentrations of colchicine (0.0%, 0.5%, 1.0%, 1.5%, and 2.0%) in various exposure times (12, 24 and 48 h), using in two experiments. In the first, were applied to the seeds by immersing method. In the second, were applied to shoot apical meristems by dropping method. The results showed significant effects of different interactions between colchicine concentration and exposure period on the seed germination, seedling survival rate and seedling characters. By increasing of the colchicine concentration the seed germination and seedling survival rate decreased significantly in colchicine concentrations (0.15 and 0.2%). Frequency of stomata decreased and on the opposite the stomata length and width increased with increases the colchicine concentrations. Polyploidy seedlings show vegetative growth superiority yield compared to diploids seedlings, leaf area in treated plants was larger and with deep green pigmentation as compared to the control seedlings. Seed treatment method was found to be more efficient than shoot apical meristems treatment method in producing tetraploid and mixoploid plants, colchicine solutions at 0.1% and 1.5% in 24 h. and 48 h. was found most effectively produced polyploidy and inducing variation in both investigations.

Class I KNOX Is Related to Determinacy during the Leaf Development of the Fern Mickelia scandens (Dryopteridaceae)

Unlike seed plants, ferns leaves are considered to be structures with delayed determinacy, with a leaf apical meristem similar to the shoot apical meristems. To better understand the meristematic organization during leaf development and determinacy control, we analyzed the cell divisions and expression of Class I KNOX genes in Mickelia scandens, a fern that produces larger leaves with more pinnae in its climbing form than in its terrestrial form. We performed anatomical, in situ hybridization, and qRT-PCR experiments with histone H4 (cell division marker) and Class I KNOX genes. We found that Class I KNOX genes are expressed in shoot apical meristems, leaf apical meristems, and pinnae primordia. During early development, cell divisions occur in the most distal regions of the analyzed structures, including pinnae, and are not restricted to apical cells. Fern leaves and pinnae bear apical meristems that may partially act as indeterminate shoots, supporting the hypothesis of homology between shoots and leaves. Class I KNOX expression is correlated with indeterminacy in the apex and leaf of ferns, suggesting a conserved function for these genes in euphyllophytes with compound leaves.