WP3-1 The Function of Alternative Splicing in Stress Adaptation in Brassica rapa Varieties
PI – Prof. Dr. Sascha Laubinger (Dept. of General Genetics)
Institute of Biology, Faculty of Science 1, MLU
Postdoc – Hui Sheng
Pre-mRNA splicing is a crucial regulatory mechanism in plants for adapting to rapidly changing environmental conditions. To breed crops adapted to future environmental conditions, particularly those caused by climate change, it has already been shown that certain master splicing regulators can increase the fitness of these plants. However, the exact target pre-mRNAs and how splicing individual pre-mRNAs can increase the fitness of a crop are largely unknown. This project aims to address the following questions:
1. What changes in splicing patterns occur in different varieties of the brassica vegetable Brassica rapa under drought and heat stress?
2. Which alternatively spliced pre-mRNAs contribute to improved plant productivity under stress conditions?
3. Can changes in splicing patterns and the effects of splicing variants be used to select and breed better varieties for Brassica rapa cultivation under future climate conditions?
The proposed project leverages the extensive expertise and methodological resources of the Department of General Genetics, whose main research focus is the experimental analysis of alternative splicing processes in plants. The goal is to test concepts developed using model organisms in crop plants and characterize their effects on their stress tolerance.
WP3-2 From Model Plant to Crop: ELF3 as a Potential Tool for Acclimatizing Crops to High Temperatures
PIs – Dr. Carolin Delker/Prof. Dr. Marcel Quint (Dept. of Crop Yield Physiology)
Institute of Agricultural and Nutritional Sciences, Faculty of Science 3, MLU
Postdoc – Valeria Maricel Santoro
Rising global temperatures threaten crop productivity by disrupting plant growth, development, and yield—even with modest increases. In Arabidopsis thaliana, responses to warm temperatures and low light involve overlapping signaling pathways that help coordinate environmental adaptation. It remains unclear whether these mechanisms can be leveraged to improve climate resilience in crops. This project aims to translate insights from Arabidopsis into Brassica rapa, a diploid crop species that includes vegetables and oilseed varieties (e.g., Chinese cabbage, turnips). As a close relative of oilseed rape (Brassica napus), findings in B. rapa have broad agricultural relevance. We will:
- Phenotype temperature responses across B. rapa varieties using automated image-based analysis (CropScore) and complementary heated field trials in collaboration with Utrecht University. This will identify temperature-sensitive and resilient lines.
- Sequence and characterize ELF3 orthologs, a key temperature and circadian regulator in Arabidopsis. ELF3 may function as a thermosensor in Brassicaceae, relying on prion-like sequence motifs.
- Test ELF3 function across species by evaluating B. rapa alleles for their ability to rescue temperature phenotypes in Arabidopsis elf3 mutants and by generating CRISPR knockouts in B. rapa for functional analysis.
- Use transient mesophyll protoplast assays to study ELF3 protein-protein interactions, focusing on known interactors involved in light, temperature, and circadian signaling.
This work will identify genetic targets to improve temperature resilience in crops, contributing to sustainable agriculture under climate change.
WP3-3 Optimizing Starch Biosynthesis in Dicotyledonous Plants
PIs – Dr. Manish Raorane/Prof. Dr. Björn Junker (Department of Drug Biosynthesis)
Institute of Pharmacy, Faculty of Science 1, MLU
Starchy plant organs are essential for global food security and serve as raw materials for bioethanol, bioplastics, and pharmaceuticals. Enhancing starch biosynthesis is therefore critical for both nutrition and industry. In cereals (monocots), a cytosolic AGPase produces ADP-glucose, which is efficiently imported into plastids via an ADP-glucose transporter, forming an energy-saving “phosphate cycle.” In contrast, most dicots synthesize ADP-glucose within the plastids, leading to energy loss (~21.6 kJ/mol) due to the breakdown of pyrophosphate. This less efficient pathway partly explains their lower starch content. To address this, we have introduced a barley-derived cytosolic AGPase and ADP-glucose transporter into pea seeds. Surprisingly, lines expressing only the transporter already show increased seed size and starch content, likely due to endogenous sucrose synthase generating ADP-glucose in the cytosol. This project will:
- Quantify metabolic fluxes in developing pea embryos using ^13C metabolic flux analysis (13C-MFA) and tandem mass spectrometry.
- Cross both transgenic lines to assess combined effects on seed size and starch yield.
- Perform enzyme assays and metabolite profiling using state-of-the-art LC-Q-Orbitrap and GC-Q-TOF mass spectrometry.
- Apply this strategy to potato, a key dicot crop, by stably introducing the same components to enhance starch content in tubers.
This approach offers a promising route to energy-efficient starch biosynthesis in major dicot crops.
WP3-4 Combating Virus-Induced Bee Declines Using New Methods with RNA Drugs
PIs – Prof. Dr. Sven-Erik Behrens (Department of Microbial Biotechnology)
Institute of Biochemistry and Biotechnology, Faculty of Science 1, MLU
Prof. Dr. Robert Paxton (Department of General Zoology)
Institute of Biology, Faculty of Science 1, MLU
The western honey bee (Apis mellifera) is critical for agricultural pollination and biodiversity. However, rising winter colony losses, mainly due to infection by Deformed Wing Virus (DWV) genotypes transmitted by the parasitic mite Varroa destructor (Vd), pose a serious threat to food security and ecosystem health. Traditional chemical treatments are increasingly ineffective and environmentally risky. This project explores an innovative RNA interference (RNAi) strategy to combat DWV and Vd. RNAi, a natural antiviral mechanism, involves Dicer enzymes producing small interfering RNAs (siRNAs) from double-stranded RNA (dsRNA), which then guide Argonaute proteins to degrade viral or pathogenic RNAs. While RNAi has been used against DWV and Vd before, its effectiveness is limited: Dicer typically generates large pools of siRNAs, but only a few, those targeting accessible regions of RNA (“a-sites”), are truly effective (“esiRNAs”). The Department of Microbial Biotechnology has developed a patented plant-based eNA screen to reliably identify these effective siRNAs (esiRNAs), and a method to produce engineered dsRNAs (edsRNAs) enriched in esiRNA sequences. These technologies have already shown strong results against plant pathogens. In collaboration with the Department of General Zoology, this project will:
- Identify esiRNAs and edsRNAs targeting DWV genomes and Vd mRNAs.
- Test their antiviral and antiparasitic efficacy in honey bees.
- Use a yeast-based delivery system to produce and administer inactivated, RNA-loaded yeast as an oral treatment for bee colonies.
This novel, transgene-free approach could offer a safe, targeted, and scalable solution for protecting honey bee health.