Embryogenic cells in Dactylis glomerata L. (Poaceae) explants identified by cell tracking and by SERK expression

Single mesophyll cells in leaf explants of Dactylis glomerata L. (Dactylis) that were competent to form somatic embryos directly or through callus were identified by semi-automatic cell tracking. These competent cells were a subpopulation of small, isodiametric, cytoplasm-rich cells located close to the vascular bundles. Using whole mount in situ hybridization, we showed that a similar subpopulation of cells expressed the Somatic Embryogenesis Receptor-like Kinase (SERK) gene during the induction of embryogenic cell formation. In both leaf explants and suspension cultures, a transient pattern of SERK gene expression was found during early embryo development, up to the globular stage. In later embryo stages, SERK mRNA was present in the shoot apical meristem, scutellum, coleoptile and coleorhiza

Embryogenic cells in Dactylis glomerata L. (Poaceae) explants identified by cell tracking and by SERK expression

Single mesophyll cells in leaf explants of Dactylis glomerata L. (Dactylis) that were competent to form somatic embryos directly or through callus were identified by semi-automatic cell tracking. These competent cells were a subpopulation of small, isodiametric, cytoplasm-rich cells located close to the vascular bundles. Using whole mount in situ hybridization, we showed that a similar subpopulation of cells expressed the Somatic Embryogenesis Receptor-like Kinase (SERK) gene during the induction of embryogenic cell formation. In both leaf explants and suspension cultures, a transient pattern of SERK gene expression was found during early embryo development, up to the globular stage. In later embryo stages, SERK mRNA was present in the shoot apical meristem, scutellum, coleoptile and coleorhiza

Estimating the motion of plant root cells from in vivo confocal laser scanning microscopy images

This is an author-created version of a paper to be published in the Springer journal Machine Vision and Applications. The published version will be available at www.springerlink.com) Images of cellular structures in growing plant roots acquired using confocal laser scanning microscopy (CLSM) have some unusual properties that make motion estimation challenging. These include multiple motions, non-Gaussian noise and large regions with little spatial structure. In this paper, a method for motion estimation is described that uses a robust multi-frame likelihood model and a technique for estimating uncertainty. An efficient region-based matching approach was used followed by a forward projection method. Over small timescales the dynamics are simple (approximately locally constant) and the change in appearance small. Therefore a constant local velocity model is used and the MAP estimate of the joint probability over a set of frames is recovered. Occurrences of multiple modes in the posterior are detected, and in the case of a single dominant mode, motion is inferred using Laplace’e method. The method was applied to several Arabidopsis thaliana root growth sequences with varying levels of success. In addition, comparative results are given for three alternative motion estimation approaches, the Kanade-Lucas-Tomasi tracker, Black and Anandan’s robust smoothing method, and Markov random field based methods.

Regulação da embriogênese semática in vitro com ênfase do papel de hormonios endógenos

Different aspects of the in vitro somatic embryogenesis regulation are reviewed in this paper.work. A description of g General aspects, such as terminology, uses, stages of development and factors associated with the somatic embryogenesis, are described. is carried out. Although a brief description ofn the effects of the addition of different plant growth regulators to the culture medium wasis given, the article is centereds itself on the effect that the endogenous hormone concentrations in the initial explants and in the tissue cultures derived from them could play oin the induction and expression of somatic embryogenesis. It is significant that few to emphasize the low amount of systematic studies have been conducted, in this subject, in which different species and hormone groups were compared in cultures with and without embryogenic capacity. Moreover, the lack of correlation between the results presented in different studies the distinct works indicates that the hormone content of the cultures is not the only factor involved.Neste trabalho se faz uma revisão de diversos aspectos da regulação da embriogêneses somático in vitro. Vários aspectos gerais a este fenômeno tem sido discutidos, tais como a definição de terminologia, descrição de eventuais aplicações, seus estados de desenvolvimento e outros fatores associados com sua indução e expressão. Embora se faça uma breve descrição do efeito da adição de diferentes reguladores de crescimento ao meio de cultivo, o artigo está centrado no efeito que as concentrações hormonais endogênas nos explantes iniciais e nos cultivos in vitro derivados deles podem ter na indução e expressão da embriogênese somática. Tem de se fazer ênfase na pouca quantidade de estudos sistemáticos realizados neste tema que comparem em várias espécies e diferentes grupos hormonais em cultivos com e sem competência embriogênica. Finalmente, indica-se que a falta de correlação entre os resultados destes poucos trabalhos parece indicar que os conteúdos hormonais endôgenos não são os únicos fatores envolvidos neste fenômeno.Grman Academic Exchange Service//DAAD/AlemaniaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Centro para Investigaciones en Granos y Semillas (CIGRAS