The quest for molecular regulation underlying unisexual flower development

The understanding of the molecular mechanisms responsible for the making of a unisexual flower has been a long-standing quest in plant biology. Plants with male and female flowers can be divided mainly into two categories: dioecious and monoecious, and both sexual systems co-exist in nature in ca of 10% of the angiosperms. The establishment of male and female traits has been extensively described in a hermaphroditic flower and requires the interplay of networks, directly and indirectly related to the floral organ identity genes including hormonal regulators, transcription factors, microRNAs, and chromatin-modifying proteins. Recent transcriptomic studies have been uncovering the molecular processes underlying the establishment of unisexual flowers and there are many parallelisms between monoecious, dioecious, and hermaphroditic individuals. Here, we review the paper entitled "Comparative transcriptomic analysis of male and female flowers of monoecious Quercus suber" published in 2014 in the Frontiers of Plant Science (volume 5 |Article 599) and discussed it in the context of recent studies with other dioecious and monoecious plants that utilized high-throughput platforms to obtain transcriptomic profiles of male and female unisexual flowers. In some unisexual flowers, the developmental programs that control organ initiation fail and male or female organs do not form, whereas in other species, organ initiation and development occur but they abort or arrest during different species-specific stages of differentiation. Therefore, a direct comparison of the pathways responsible for the establishment of unisexual flowers in different species are likely to reveal conserved modules of gene regulatory hubs involved in stamen or carpel development, as well as differences that reflect the different stages of development in which male and/or female organ arrest or loss-of-function occurs.This work was funded by FEDER funds through the Operational CompetitivenessProgramme-COMPETE and by National Funds through FCT—Fundação para a Ciência e a Tecnologia under the project FCOMP—01—0124—FEDER—019461 (PTDC/AGRGPL/118508/2010) and the sub-project SOBREIRO/0019/2009 within the National Consortium (COEC—Cork Oak ESTs Consortium). RS was supported by funding from FCT with a PhD grant (ref. SFRH/BD/84365/2012). HS was supported by funding from FCT with a PhD grant (ref. SFRH/BD/111529/2015). MC was supported by funding from FCT with a grant SFRH/BSAB/113781/2015.info:eu-repo/semantics/publishedVersio

MicroRNA Expression Analysis in the Cellulosic Biofuel Crop Switchgrass (Panicum virgatum) under Abiotic Stress

Switchgrass has increasingly been recognized as a dedicated biofuel crop for its broad adaptation to marginal lands and high biomass. However, little is known about the basic biology and the regulatory mechanisms of gene expression in switchgrass, particularly under stress conditions. In this study, we investigated the effect of salt and drought stress on switchgrass germination, growth and the expression of small regulatory RNAs. The results indicate that salt stress had a gradual but significant negative effect on switchgrass growth and development. The germination rate was significantly decreased from 82% for control to 36% under 1% NaCl treatment. However, drought stress had little effect on the germination rate but had a significant effect on the growth of switchgrass under the severest salinity stress. Both salt and drought stresses altered the expression pattern of miRNAs in a dose-dependent manner. However, each miRNA responded to drought stress in a different pattern. Salt and drought stress changed the expression level of miRNAs mainly from 0.9-fold up-regulation to 0.7-fold down-regulation. miRNAs were less sensitive to drought treatment than salinity treatment, as evidenced by the narrow fold change in expression levels. Although the range of change in expression level of miRNAs was similar under salt and drought stress, no miRNAs displayed significant change in expression level under all tested salt conditions. Two miRNAs, miR156 and miR162, showed significantly change in expression level under high drought stress. This suggests that miR156 and miR162 may attribute to the adaption of switchgrass to drought stress and are good candidates for improving switchgrass as a biofuel crop by transgenic technology

How Many Turkeys Did It Take to Make a Blanket?

This talk was presented at the Canyons of the Ancients National Monument Visitor Center in Dolores, Colorado

SARAH / AZNAVOUR, PLANTE. TEQUILA / C. RIO, SALVET. DERRIERE LA TETE / MERY, ITHIER, SALVET. CA C'EST L'AMOUR / PORTER, LARUE ; Danièle DUPRE, avec l'orch. F. VERSTRATE

Titre uniforme : [Tequila]Titre uniforme : [Ça c'est l'amour]Titre uniforme : [Sarah]Titre uniforme : [Ça c'est l'amour]BnF-Partenariats, Collection sonore - BelieveContient une table des matière

The role of small RNAs in vegetative shoot development

Shoot development consists of the production of lateral organs in predictable spatial and temporal patterns at the shoot apex. To properly integrate such programs of growth across different cell and tissue types, plants require highly complex and robust genetic networks. Over the last twenty years, the roles of small, non-coding RNAs (sRNAs) in these networks have become increasingly apparent, not least in vegetative shoot growth. In this review, we describe recent progress in understanding the contribution of sRNAs to the regulation of vegetative shoot growth, and outline persisting experimental limitations in the field