Immink Group – Molecular control of flowering and reproduction of plants

How do plants, as sessile organisms, survive under ever-changing and sometimes harsh environmental conditions? This intriguing question is central to our research group. The answer can be found in the enormous flexibility and adaptability of plants regarding the timing of flowering and germination of seeds; two biological processes that appear to be interconnected at the molecular level.

An efficient and robust reproduction system is the key to survival of the species. The reproductive cycle of plants starts with the initiation of flowering and ends with the formation of viable and potent seeds. Furthermore, there are plants which, in addition to this sexual reproduction, can reproduce vegetative by forming storage organs such as bulbs and tubers. Plants adapt the timing of all these developmental phase transitions to environmental factors such as photoperiod, light quality, nutrient availability and ambient temperature. These different signals are sensed and integrated with endogenous signals and parameters, including hormone levels and plant age.

We focused our research on the effects of ambient temperature differences on flowering induction, the formation and outgrowth of vegetative storage organs, and the establishment of seed dormancy. Identifying the key regulatory genes in these processes and obtaining a deeper understanding of the underlying molecular mechanisms is extremely relevant considering global warming and more extreme temperature variation that plants need to cope with due to climate change. Our previous research revealed that gene splicing of specific key flowering time regulators, such as the MADS domain transcription factor FLM, is temperature sensitive. Furthermore, we showed that specific chromatin modifications play a role, and these may be key in ‘memorizing’ previously experienced temperature conditions. Finally, we study how members of the PEBP family steer vegetative versus sexual reproduction. The mobile and flowering-inducing protein ‘Florigen’ (FT) is the best studied example of this family and full-fills its specific functions by complex formation with TCP and bZIP transcription factors.

Understanding how flowering and reproduction is controlled by environmental cues enables breeders and plant growers to control these processes in food, feed, and ornament crops, and to optimize yield in a sustainable manner. Additionally, it provides breeders with speed-breeding tools based on precousious flowering and life cycle shortening.