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Talks related to plants in the University of Cambridge
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Thu 21 Oct 13:00: Epigenetic Reprogramming in Plant Germlines

Fri, 15/10/2021 - 14:24
Epigenetic Reprogramming in Plant Germlines

Germ cells are “immortal” as they can be indefinitely transmitted through generations. Establishment of germ cell immortality and identity requires extensive reprogramming of the chromatin state. Understanding this epigenetic reprogramming is crucial for the elucidation of germline biology. Conversely, germlines are essential for understanding epigenetics because they mediate inheritance and undergo large-scale epigenetic changes.

My lab established the Arabidopsis male germline – composed of four cell types produced by three sequential cell divisions – as a model system, and developed advanced techniques for cell isolation and epigenomic analysis. The ability to examine each germline cell type, combined with the high tolerance of Arabidopsis for epigenetic disruption, allows precise and powerful genetic analysis. Using this unique system, my lab aims to elucidate the scope, mechanism and biological significance of plant germline epigenetic reprogramming.

Contact reception@plantsci.cam.ac.uk for a Zoom link prior to a talk if you are not on our mailing list. Due to having to go online, we are restricting the talks to University of Cambridge and alumni to keep them as informal as possible.

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Wed 27 Oct 15:00: The 4th dimension of transcriptional networks: TIME

Wed, 13/10/2021 - 16:31
The 4th dimension of transcriptional networks: TIME

Abstract not available

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Thu 11 Nov 13:00: Plant Sciences Seminar

Mon, 04/10/2021 - 15:20
Plant Sciences Seminar

Contact reception@plantsci.cam.ac.uk for a Zoom link prior to a talk if you are not on our mailing list. Due to having to go online, we are restricting the talks to University of Cambridge and alumni to keep them as informal as possible.

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Thu 28 Oct 13:00: Functional Macroevolution of Transcription Factors in Land Plants

Mon, 04/10/2021 - 13:58
Functional Macroevolution of Transcription Factors in Land Plants

We use the model liverwort Marchantia polymorpha to understand fundamental questions of evolutionary biology. One of the advantages of this model system is its genome presents low redundancy of transcription factor genes compared to other plant species. During my PhD thesis, I studied the molecular evolution of the class I homeodomain leucine-zipper (C1HDZ) in Marchantia polymorpha. In flowering plants, C1HDZ transcription factor function is primarily associated with abiotic stress responses. However, loss-of-function alleles of MpC1HDZ (Mpc1hdzge) did not exhibit phenotypes associated with abiotic stress. Rather, Mpc1hdzge mutant plants present a reduced number of oil body cells as the most remarkable developmental defect. Oil bodies, a synapomorphy of liverworts, are organelles in specialized cells that accumulate secondary metabolites, but their function and development are poorly understood. Using these plants, we interrogated the biological function of oil bodies. Briefly, we found Mpc1hdzge are more susceptible to herbivory and cannot accumulate terpenoid compounds. Toxic compounds accumulated in oil bodies are an important defence strategy against herbivores, an analogous function to glandular trichomes in flowering plants. In addition, C1HDZ genes were co-opted to regulate separate responses to biotic and abiotic stressors in two distinct land plant lineages. Our findings and other works in the field suggest that the expression pattern of transcription factor expression is key in their functional macroevolution.

Contact reception@plantsci.cam.ac.uk for a Zoom link prior to a talk if you are not on our mailing list. Due to having to go online, we are restricting the talks to University of Cambridge and alumni to keep them as informal as possible.

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Thu 04 Nov 13:00: Investigating the Origin of Nanostructures on Flowers

Mon, 04/10/2021 - 13:55
Investigating the Origin of Nanostructures on Flowers

Part of Hibiscus trionum petals have a wrinkled cuticle that creates a visual signal perceived by pollinators. These wrinkles are ordered nanostructures capable of scattering light. They develop from the cuticle on epidermal cells and maintain their orientation across several cells, forming tissue-wide patterns. Our experiments demonstrate that they result from mechanical instabilities rather than from the guided deposition of material secreted by the cell. We have performed a detailed characterization of Hibiscus trionum petal development and the mechanical properties of its cuticle to understand how a buckling process produces these microscopic ordered structures.

Contact reception@plantsci.cam.ac.uk for a Zoom link prior to a talk if you are not on our mailing list. Due to having to go online, we are restricting the talks to University of Cambridge and alumni to keep them as informal as possible.

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Thu 25 Nov 13:00: Plant Sciences Seminar

Wed, 29/09/2021 - 10:06
Plant Sciences Seminar

Contact reception@plantsci.cam.ac.uk for a Zoom link prior to a talk if you are not on our mailing list. Due to having to go online, we are restricting the talks to University of Cambridge and alumni to keep them as informal as possible.

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Thu 04 Nov 13:00: Plant Sciences Seminar

Wed, 29/09/2021 - 10:06
Plant Sciences Seminar

Contact reception@plantsci.cam.ac.uk for a Zoom link prior to a talk if you are not on our mailing list. Due to having to go online, we are restricting the talks to University of Cambridge and alumni to keep them as informal as possible.

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Thu 11 Nov 13:00: Plant Sciences Seminar

Wed, 29/09/2021 - 10:06
Plant Sciences Seminar

Contact reception@plantsci.cam.ac.uk for a Zoom link prior to a talk if you are not on our mailing list. Due to having to go online, we are restricting the talks to University of Cambridge and alumni to keep them as informal as possible.

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Thu 18 Nov 13:00: Decoupling Photoprotective Roles of Carotenoids in the PSII Light Harvesting Complexes for Improved Plant Growth

Wed, 29/09/2021 - 10:05
Decoupling Photoprotective Roles of Carotenoids in the PSII Light Harvesting Complexes for Improved Plant Growth

Photosynthesis is a promising target for optimisation to enhance biomass accumulation in plants. As the initial step in this complex process, light harvesting plays a pivotal role and depends on the prevailing light conditions.

While a minimum level of light intensity is required for the activation of photosynthetic electron transfer between photosystems, high light intensities can damage the photosynthetic machinery in the thylakoid membrane of chloroplasts by the formation of Reactive Oxygen Species (ROS), giving rise to photoinhibition.

This can be prevented by the action of several photoprotective mechanisms, including the dissipation of excess light energy as heat (non-photochemical quenching, NPQ ), and ROS scavenging. A specific group of carotenoids, the xanthophylls, are known to be involved in both mechanisms by binding to the subunits of the light harvesting complexes (LHCs) connected to the photosystems.

Under fluctuating light conditions, the rate of NPQ (de)activation is transiently limiting photosynthetic efficiency and can be accelerated by speeding up the xanthophyll cycle (Kromdijk et al., 2016). This, however, may in turn compromise the ROS scavenging capacity of xanthophylls and adversely affect plant growth.

Therefore, it is our objective to decouple both functions of xanthophylls in LHCs in plants to ultimately optimise plant growth without compromising ROS scavenging capacity.

Contact reception@plantsci.cam.ac.uk for a Zoom link prior to a talk if you are not on our mailing list. Due to having to go online, we are restricting the talks to University of Cambridge and alumni to keep them as informal as possible.

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Thu 21 Oct 13:00: Epigenetic Reprogramming in Plant Germlines

Wed, 22/09/2021 - 11:35
Epigenetic Reprogramming in Plant Germlines

My lab studies germline epigenetics. Using plant male germlines as models, our main focus is to elucidate the mechanism and biological significance of germline epigenetic reprogramming. We are also interested in how somatic nurse cells communicate with the germline, how the environment affects fertility, and how environment-induced epigenetic memories are transmitted or erased in germlines.

Contact reception@plantsci.cam.ac.uk for a Zoom link prior to a talk if you are not on our mailing list. Due to having to go online, we are restricting the talks to University of Cambridge and alumni to keep them as informal as possible.

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Thu 14 Oct 13:00: Redox and ROS Signaling During Plant Responses to Abiotic Stress

Wed, 22/09/2021 - 11:34
Redox and ROS Signaling During Plant Responses to Abiotic Stress

Plants grow and reproduce within a highly dynamic environment that can see abrupt changes in conditions, such as light intensity, temperature, humidity, and/or the presence of different pathogens and insects. Recent studies revealed that plants can respond within minutes to some of these conditions, engaging many different metabolic and molecular networks, as well as rapidly altering their stomatal aperture.

Some of these rapid responses were further shown to propagate throughout the entire plant via waves of reactive oxygen species (ROS), redox, membrane potential, Ca2+, and hydraulic pressure, mediated through the plant vascular system. New findings reveal that several different plasmodesmata-associated proteins, calcium channels, and respiratory burst oxidase homologs (RBOHs) play key roles in regulating and integrating these signals. In addition, new findings identified a key role for ROS and different plant hormones in mediating the acclimation of plants to conditions of stress combination.

The role of ROS in sensing, transducing, and activating plant responses to environmental stresses will be discussed along with different models and hypotheses as to how ROS are involved in the rapid systemic signaling process of plants and how they integrate different signal transduction processes during stress combination.

Contact reception@plantsci.cam.ac.uk for a Zoom link prior to a talk if you are not on our mailing list. Due to having to go online, we are restricting the talks to University of Cambridge and alumni to keep them as informal as possible.

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Thu 04 Nov 13:00: Plant Sciences Seminar

Tue, 21/09/2021 - 15:46
Plant Sciences Seminar

Abstract not available

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Thu 02 Dec 13:00: Endogenous Pararetroviruses Regulate Gene Expression in Hybrids

Tue, 21/09/2021 - 15:46
Endogenous Pararetroviruses Regulate Gene Expression in Hybrids

Hybrids (progeny from two different species or genera) may display characteristics that are out of the range of the parents. For that reason, hybridisation has been exploited in crop breeding programmes for centuries to obtain plants that produce more fruits or are more vigorous.

Interspecific hybrids may undergo “genomic shock,” as coined by Barbara McClintock, leading to perturbation of gene expression and activation of transposons. Genomic shock can be seen as a source of heritable variation, able to trigger extensive phenotypic effects. However, the molecular mechanisms associated are not well understood.

We predict that small RNAs (sRNAs) may be involved in genomic shock. These 20-24nt long sRNA molecules can mediate gene silencing at transcriptional or posttranscriptional level. In hybrids, due to the variability in the sRNA population between species, sRNAs from one parent may find new targets in the genome of the other parent, modifying gene expression.

To unravel the mechanisms of hybridisation-induced genome shock, we study the F4 generation from a cross of tomato and a wild relative. Our results suggest that hybridisation activates integrated viral genomes of EPR Vs (endogenous pararetroviruses), which are normally latent and found broadly in the plant kingdom. This activation leads to an increased production of sRNAs, as these elements are repressed through post-transcriptional gene silencing.

EPR Vs are a viral reservoir that upon activation can actually cause viral disease. Although why some plants show symptoms while others remain healthy is not known, we are paving the way: we have identified a mechanism that controls the activation of EPRV in hybrids, mediated by Dicer and sRNAs, providing a first molecular handle for EPRV control and the effects of hybridisation in plant genomes.

These findings also implicate that hybridization-induced genome shock leading to EPRV activation and sRNA silencing, as causing changes in gene expression. Such hybridization-induced variation in gene expression could increase the range of traits available for selection in natural evolution or in breeding for agriculture.

Contact reception@plantsci.cam.ac.uk for a Zoom link prior to a talk if you are not on our mailing list. Due to having to go online, we are restricting the talks to University of Cambridge and alumni to keep them as informal as possible.

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Thu 28 Oct 13:00: Investigating the Origin of Nanostructures on Flowers

Mon, 20/09/2021 - 13:57
Investigating the Origin of Nanostructures on Flowers

Part of Hibiscus trionum petals have a wrinkled cuticle that creates a visual signal perceived by pollinators. These wrinkles are ordered nanostructures capable of scattering light. They develop from the cuticle on epidermal cells and maintain their orientation across several cells, forming tissue-wide patterns. Our experiments demonstrate that they result from mechanical instabilities rather than from the guided deposition of material secreted by the cell. We have performed a detailed characterization of Hibiscus trionum petal development and the mechanical properties of its cuticle to understand how a buckling process produces these microscopic ordered structures.

Contact reception@plantsci.cam.ac.uk for a Zoom link prior to a talk if you are not on our mailing list. Due to having to go online, we are restricting the talks to University of Cambridge and alumni to keep them as informal as possible.

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Thu 02 Dec 13:00: Plant Sciences Seminar

Tue, 14/09/2021 - 15:14
Plant Sciences Seminar

Abstract not available

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Thu 25 Nov 13:00: Plant Sciences Seminar

Tue, 14/09/2021 - 15:13
Plant Sciences Seminar

Abstract not available

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Thu 18 Nov 13:00: Plant Sciences Seminar

Tue, 14/09/2021 - 15:10
Plant Sciences Seminar

Abstract not available

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