Development, flowers, photoreceptors, and organelles

The term ‘development’ encompasses research towards organs or reproduction, but could also include responses to light by microbes and tissues or organelles. For the former two completely different examples were explained: one using Arabidopsis with a specific mutated F-box protein, which causes reproductive problems and for which subcellular localization and interaction partners were investigated. The second was presented in a talk with a broader approach given by a guest scientist from Portugal, who explained the question how asymmetric flowers are made on a molecular level and when this development occurred in the land plant lineages. The talk highlighted which specific genetic factors are needed to make the dorsal identity of flowers and with which other factors they interact. Finally, the question was discussed as to when was this module established and which functions it may have had in early land plants such as Marchantia. Detailed work was presented on the characteristics of blue-light photoreceptors of Chlamydomonas reinhardtii of the DASH type cryptochrome and its regulatory function for cellular metabolism using mutant analysis. Also light as a regulatory factor was described for differences in metabolic processes from a heterotrophic soil bacterium Pseudomonasprotegens. The presentation showed a novel role for light instability of a signaling molecule. An example for factors important for organelle development was presented with Whirly proteins that are known to bind to DNA with a specific domain and also to localize to the DNA-containing organelles and the nucleus of higher plants. The presentation here looked at transport of these proteins into chloroplast and alternative organelles. An important molecule in plant biology is Rubisco, which was analyzed in a population of Fragaria varieties in which its evolution occurred through redistribution of structural dynamics, rather than modification of catalytic architecture. 

Abiotic stressors including malnutrition

Several major stress factors were discussed during the meeting: salt stress, nutritional deprivation and waterlogging. The latter results in oxygen deprivation, which holds a completely different challenge for a plant to cope with. One presentation described the tolerance response of Arabidopsis mutants with higher or lower NO content; NO being a known signal involved in waterlogging determining different physiological, biochemical and molecular parameters. The second dealt with the functional characterization of components involved in the NO modulation and hypoxia response of Arabidopsis. The aim of another presentation was to screen halophytic relatives of crops for their physiological responses to salt stress and a possible use of the traits in comparison to sensitive plants. Malnutrition also presents a stressor for plants and therefore in the field high rates of fertilizations are used. The project therefore dealt with N-fertilization of rapeseed and tried to identify markers for early N-deprivation using drones in combination with molecular methods. An idea to generate more stress-tolerant plants in the model Arabidopsis used Single Nucleotide Polymorphisms creating phenotypic diversity within natural populations. In turn this could result in the adaptation of populations to diverse environmental conditions. 

Interactions also among more than two partners

Interactions between probably expected partners, but even more with unexpected ones were highlighted during the meeting. So, a marine Chlamydomonas species with two bacteria or barley with Nostoc species. In the former, a complex series of experiments established mutualisms between three different partners. In the latter endophytic localization and differentiation in barley roots under nitrogen deficiency was described to occur, which resulted in better growth of the host plants. Another presentation was investigating complicated tripartite interactions with sugar beet, an insect vector and phytopathogenic bacteria, the latter need the host and vector to transfer and prosper. Physiological parameters were investigated in terms of understanding possible resistance mechanisms in this complex system. 

Methods and proof-of-concept

While there were several presentations specifically dealing with method development, other talks also of course included the presentation of methodology needed to complete the work. The aim here was the achievement of multi colored marker lines based on using only one construct for two and even three different fluorescent dyes which would need only one transformation event. The majority of presentations were directed to alternative and/or better metabolite or protein production systems. One presentation elucidated the possibility to make secondary metabolites in guttation fluids of plants, which would reduce the background of other compounds. Other possible systems to produce proteins are cyanobacteria or algae. Also here, the biological systems need to be understood. In cyanobacteria protein secretion is occurring via a two-step process. Two different cyanobacteria were used and characterized in terms of salt, nutrient and buffer effects on protein secretion. Bacterial microcompartments are self-assembling, protein-based structures that confine specific enzymes and substrates. Proof-of-concept study on heterologous assembly of such microcompartments in cyanobacteria took structures into account, which are needed for biosynthesis of chemicals. In the green algal species Chlamydomonas reinhardtii higher glycolate production by random mutagenesis should be achieved. The talk presented evidence in the project for the proof-of-principle to work.

Hands on Open Science 

The presentations from the bench also frequently pointed out problems, e.g., that methods were not well described in publications, or that data cannot be (partially) reproduced. The presentation about the network on “open science” gave advice on how every individual can improve on that. Consequently, the talk encompassed more details on three important topics, namely data management, method descriptions and data presentation/visualization.

Farewell

We are looking forward to the next conference, taking place in Leipzig, which will already be the 25th of the series.

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in March 2026

Prof. Dr. Jutta Ludwig-Müller, Professur für Pflanzenphysiologie, TU Dresden, https://tu-dresden.de/mn/biologie/pflanzenphysiologie