Showing: 11 - 15 of 15 RESULTS
The cell space – A journey in spatially resolved transcriptomics: from animal tissues to plants
Spatial context is fundamental in understanding how tissues are formed and how single cells function and interact together. Most of the available spatial technologies are only available for mammalian tissues limiting the exploration of plant systems. In this talk, I will present our recent developments in Spatial Transcriptomics with a specific focus on plants and microbes. https://www.spatialresearch.org/research-giacomello-lab/
The cell space – A twist in the thale: an update on auxin-mediated cell elongation
Plants own an amazing high degree of developmental plasticity by regulating cell growth and division in response to internal and external signals. This plasticity is controlled by local maxima and minima of the signalling molecule, auxin. These are generated by the cell-to-cell movement of auxin, a unique process not yet described in non-plant organisms or for other hormones. This so-called polar auxin transport is thought to be mainly provided by the action of auxin exporters of the ABCB and PIN families. Interestingly, abcb loss-of-function mutants reveal a strong developmental phenotype, including a helical, non-handed disorientation of epidermal layers. In my talk, I will address the morphological and molecular background for this “twisted syndrome” by dissecting the individual roles of ABCB proteins. It appears that all auxin-transporting ABCBs are regulated on the transport level by transient cis-trans isomerization of a conserved and diagnostic D/E-P motif. This catalytic activity is provided by PPIases, including the FKBP42, TWISTED DWARF1. Beside acting as PPIase, TWISTED DWARF1 functions also as a co-chaperone of HSP90 stabilizing ABCBs at the plasma membrane, indicating a dual role during ABCB regulation. Our findings classify the TWISTED DWARF1-HSP90 module as a positive regulator of polar auxin transport providing plasticity to ABCB-controlled auxin transport and plant development. https://www.unifr.ch/bio/en/research/plant-and-microbial-biology/geisler.html
The cell space – When it is the right time to divide: parental regulation of cell division during reproduction
During the process of fertilization of sexually reproducing organisms, maternal and paternal gametes, egg and sperm respectively, fuses together to give rise to the zygote. Differently from animal, in flowering plants the so-called double fertilization involves a second female gamete, the central cell, from which originates the endosperm, a triploid and ephemeral tissue that nurtures and sustains the growth of the embryo. The fusion of the paternal and maternal gametes generates a series of dramatic events, including the re-activation of the cell cycle that is, somehow, strongly inhibited before fertilization to avoid premature division. Genetic evidences show that both parents exert a tight control over cell cycle progression: the mother reins cell division in the seeds, whereas the father provokes the opposite. The lack of this control then has dramatic and conflicting effects as the development of seed-like structure from unfertilized ovules, or suicidal cell divisions as result of unbalanced DNA content after fertilization. The molecular mechanisms underlying these processes are yet to be fully understood. I will present some of our recent data about the characterization of such mechanisms, showing how maternal factors keep female gametes quiescent, and how paternally-derived signals trigger cell cycle progression specifically at fertilization. https://www.botinst.uzh.ch/en/research/embryology/simonini.html