Insect populations worldwide are dramatically declining. Especially insects that overwinter as eggs are in decline, as egg development strongly depends on temperature. To survive climate change, the temperature response of egg development needs to adapt. This project investigates the adaptive potential of wild insects by determining which genes underly how egg development responds to temperature in wild populations. We will investigate 12 different species to determine whether the same genes are involved in different insects. We will use this information to assess whether wild insect populations harbor variation for these genes, which is an important determinant of their adaptive potential.

Global warming due to climate change adversely affects crop yield, jeopardizing food supply for a growing world population. Breeding stress-resilient cultivars is, therefore, an urgent need. An exciting, but poorly understood phenomenon is ´thermomemory´ whereby plants ´remember´ a high temperature from the past to robustly withstand a later – and even more extreme – heatwave. During the memory period, several but not all molecular and biochemical HS-induced changes are maintained which prepares, or ‘primes’, the plant to respond more effectively to future HS events. Recently, we discovered a regulatory module vital for thermomemory and located in chloroplasts, the plants´ photosynthetic organelles. The module includes small heat shock protein HSP21, a chaperone; its sustained high level is required for maintenance of the primed state. It also includes a previously uncharacterized metalloprotease, called FtsH6, which degrades HSP21 in chloroplasts and thereby profoundly limits the plants’ thermomemory capacity. Our discovery represents the first identification of the biological function of a protease intimately involved in forging thermomemory in plants. The role of the FtsH6-HSP21 module may even extend beyond vegetative tissues: In many crops, pollen, the male reproductive tissue, is highly sensitive to elevated temperature resulting in reduced seed and fruit yield. Intriguingly, we for the first time discovered that pollen has a strong thermomemory capacity supporting increased fruit yield under conditions of repetitive HS in the widely cultivated vegetable crop tomato (Solanum lycopersicum). Furthermore, the FtsH6 gene is induced by heat in tomato pollen. Regulation of thermomemory via degradation of HSP21 is the first biological function reported for FtsH6, providing significant corroboration of its importance in HS responses. In the research proposed here, we thus aim to obtain a detailed understanding of FtsH6’s role in the regulation of thermomemory in Arabidopsis thaliana and in tomato. We will achieve this by applying advanced molecular biology, biochemical and proteomics methods to target three primary goals: (1) Identify novel protein substrates of the FtsH6 protease, assuming they include essential components of the thermomemory machinery. (2) Identify upstream transcriptional regulators of FtsH6, which may be critical hubs linking the control of thermomemory with other physiological processes. (3) Investigate the role of FtsH6 for the regulation of thermomemory in tomato pollen. All techniques required to perform the research are fully established in the applicant´s lab or excellent collaborating groups. The results obtained will not only significantly deepen our understanding of the role of the FtsH6 protease for forging plant thermomemory; they will also provide candidate genes for future breeding of crops with improved heat tolerance. With the research put forward here we establish a new research theme: an agenda on the systematic analysis of protein stability control – and its regulation – for managing the physiological and developmental responses to stress in plants.

Leek is an important crop, especially on sandy soils. Thrips is a growing pest problem in leek, requiring pesticide applications several times during the season, which causes biodiversity loss and health issues. With representatives from the entire sector, we develop practical knowledge on how to stimulate natural enemies of thrips with flowering plants and soil amendments. We do this in field experiments and – with growers – on commercial leek fields. Together, we accelerate the transition to sustainable thrips reduction in leek and other field crops, with minimal pesticides, more biodiversity and improved soil health.

Soil-borne plant pathogens are a major threat to the sustainable production of healthy crops and cost billions of euros annually. To reduce the environmental impact of pesticides and improve crop health, novel protection measures are needed. Our aim is to develop a novel method of crop protection that is sustainable and general. Specifically, we will use experimental evolution to evolve communities of beneficial root-associated bacteria that can be used to “vaccinate” soil to prevent soil-borne plant diseases. We build on the concept of “natural disease-suppressive soils”, defined as soils that eliminate or reduce specific diseases due to the concerted actions of root-associated microbes. Our novel approach will generate plant-beneficial microbiomes de novo using an experimental framework that can be applied to a broad range of soil-borne pathogens. We will provide proof-of-concept for a generic method to engineer beneficial soil microbiomes, thereby enhancing sustainable food production and safety. It will also serve as the impetus for Green Life Sciences and industry in the Netherlands and as the foundation for a larger national project to develop experimental evolution as an applied tool to evolve microbial communities for societally important functions.

Evolutionary changes occur via the slow accumulation of mutations. However, sudden changes can also occur via “major transitions” that give rise to new forms of organismal complexity. To understand this process, we developed a novel experimental system using bacterial cells that lack cell walls, called L-forms, which were fused to form polyploid cells. This fusion created a synthetic mutualism that allowed us to measure the context-dependent costs and benefits of cell-cell fusion and chromosomal coexistence. Our results are helping to understand the evolution of complex cells, similar to the transition that occurred at the origin of eukaryotes.