The growth of plants and plant organs is highly controlled by both intrinsic development programs and environmental cues. The long-term goal of my research is to obtain a holistic understanding of plant growth. To this end, a systems biology approach has been used in which many tools ranging from quantitative image analysis towards mathematical modeling have been integrated. Most of our research has been focusing on leaf growth and the understanding of the signaling networks that determine final leaf size. Interestingly, molecular mechanisms that regulated leaf size in Arabidopsis are to some extent conserved in maize. By using the experimental advantages of both model systems tremendous progress has been made in understanding plant growth. We anticipated that this knowledge will have a significant impact on our ability to select novel high yielding and climate adapted crops.
Molecular mechanisms regulating leaf size in Arabidopsis
Understanding the mechanisms that control tissue, organ and organism size are amongst the most mysterious and fascinating open questions in biology. A key concept in "size biology" is that both in animals and plants size itself is regulated. Our long-term goal is to unravel the molecular pathways that govern leaf size in Arabidopsis. One of our approaches is based on studying the action mechanisms of so-called intrinsic yield genes (IYGs) which, when mutated or overexpressed, enlarge leaf size. In most cases examined so far, enlarged leaf size results from an increased cell number without significantly affecting cell size, pinpointing to a central role of cell proliferation in size control. A detailed kinematic analysis as well as transcript and metabolome profiling is undertaken on various IYG lines. Crosses between lines with enlarged leaves reveal unexpected additive and synergistic phenotypes. Detailed computational, as well as functional analysis, has shed new light on how organ size is governed in plants. As cell proliferation plays an important role in the control of final size, genome-wide transcript profiling is performed on leaves primordia throughout the transition from proliferation to expansion, in order to identify temporally and spatially regulated genes involved in the control of these processes. In addition, novel image analysis algorithms were developed to visualize and quantify the size and shape of the cells along the proximal-distal axis of these leaves primordia.
Systems biology of tolerance to mild drought in Arabidopsis
Despite the recognized importance of drought in limiting plant growth and biomass production, little is known about the underlying molecular mechanisms. However, it is now clear that plants reduce their growth as a primary adaptation response to stress, rather than as a secondary consequence of resource limitation. In unpredictable environments, growth reduction enables plants to redistribute and save resources, ensuring reproduction even when the stress becomes extreme. However, when the episode of stress does not threaten plant survival and from the agricultural point of view, growth reduction can be seen as counter-productive, leading to unnecessary yield loss. Limiting growth reduction may thus provide a strategy to boost plant productivity under stress. Whilst stress responses of mature organs are relatively well characterized, what happens in the growing zones is much less understood. To address this gap in knowledge, physiological (growth analysis) and molecular (e.g. transcript, metabolite, and protein profiling) analyses have been undertaken to understand how growing (fully proliferating and fully expanding) Arabidopsis leaves regulate their growth in response to water deficit. Genes are further investigated using an automated phenotyping platform (WIWAM) and targeted molecular approaches.
Translational research: maize leaf development
Maize is one of world’s most important crops for food and feed. The major of objective of our research is to use the profound understanding of growth regulatory processes to improve crop yield. More specifically, our research goal is to unravel how growth of maize leaves is controlled under standard, as well as mild drought stress conditions. Maize leaf development offers great opportunities to study the dynamics of growth regulatory networks, essentially because leaf development is a linear system with cell division at the leaf basis, followed by cell expansion and maturation. Furthermore, the growth zone is relatively large, allowing easy access of tissues at different positions. We are in the process of constructing a 3D cellular map of the growth zone of the fourth leaf. RNA-seq of three different tissues (adaxial and abaxial epidermis; mesophyll), obtained by laser dissection with an interval of 2.5 mm along the growth zone will allow for the analysis of the transcriptome with high resolution. Additionally, the composition of fifty selected growth regulatory protein complexes and DNA targets of transcription factors will be determined with an interval of 5 mm along the growth zone. Computational methods will be used to construct comprehensive integrative maps of the cellular and molecular processes occurring along the growth zone. Finally, selected regulatory nodes of the growth regulatory networks are further functionally analyzed in transgenic maize. To the end, a large-scale phenotyping robot, PHENOVISION, was constructed, allowing for the daily RGB-, infrared-, and hyperspectral imaging of maize plants. Our results opens up new perspectives for the identification of optimal growth regulatory networks that can be selected for advanced breeding or for which more robust variants (e.g. reduced susceptibility to drought) can be obtained through genetic engineering. The ability to improve the growth of maize and, in analogy other cereals, could have a high impact in providing food security.
ANGUSTIFOLIA3 binds to SWI/SNF chromatin remodeling complexes to regulate transcription during Arabidopsis leaf developmentVercruyssen L, Verkest A, Gonzalez N, Heyndrickx K, Eeckhout D, Han S, Jégu T, Archacki R, Van Leene J, Andriankaja M, De Bodt S, Abeel T, Coppens F, Dhondt S, De Milde L, Vermeersch M, Maleux K, Gevaert K, Jerzmanowski A, Benhamed M, Wagner D, Vandepoele K, De Jaeger G, Inzé DPLANT CELL, 26, 210-29, 2014 Exit from Proliferation during Leaf Development in Arabidopsis thaliana: A Not-So-Gradual ProcessAndriankaja M, Dhondt S, De Bodt S, Vanhaeren H, Coppens F, De Milde L, Mühlenbock P, Skirycz A, Gonzalez N, Beemster G, Inzé DDEVELOPMENTAL CELL, 22, 64-78, 2012 Survival and growth of Arabidopsis plants given limited water are not equalSkirycz A, Vandenbroucke K, Clauw P, Maleux K, De Meyer B, Dhondt S, Pucci A, Gonzalez N, Hoeberichts F, Tognetti V, Galbiati M, Tonelli C, Van Breusegem F, Vuylsteke M, Inzé DNATURE BIOTECHNOLOGY, 29, 212-4, 2011
24/01/2014 - An intl research team led by VIB/UGent scientists identified a protein complex that controls the transition from cell division to cell specialization. These insights can be used to guide plant breeding initiatives towards higher plant productivity.
17/12/2012 - The first harvest of genetically modified corn plants in Wetteren confirms the earlier lab results: the genetically modified corn also grows larger in the field.
07/02/2012 - VIB and BASF Plant Science jointly develop TopYield Technology. This is the largest collaboration VIB has entered in the field of plant biotechnology, this project is supported by Flemish government agency IWT.
21/12/2011 - VIB has submitted an application for a field experiment with genetically modified maize. The maize becomes taller than conventional maize – at least in a greenhouse.
15/09/2011 - The rapidly growing population, accelerating climate change and a rush on biofuels are pushing plant breeders to look for crops with higher yields. Basic research into plant processes by academic and industrial scientists plays a key role.
11/05/2011 - VIB/UGent researchers have unveiled a mechanism that can be used to develop crop varieties resistant to mild droughts.
07/09/2010 - Kris Peeters, the Minister-President of Flanders, this morning visited the VIB Plant System Biology Department of the University of Ghent. He came out in support of the application of biotechnology for competitive and sustainable agriculture.
03/11/2009 - VIB and scientists at Bayer CropScience AG have developed a technology that can significantly increase crop yields as well as make them more resistant to unfavorable growing conditions.
02/09/2008 - BASF Plant Science and VIB collaborate on plant genetic mechanisms that increase yield and improve tolerance to environmental stress such as drought and cold.
21/06/2006 - The European Commission is devoting €12 million to AGRON-OMICS, a plant research consortium spearheaded by Pierre Hilson and Dirk Inzé of the Flanders Interuniversity Institute for Biotechnology (VIB) and Ghent University.
20/03/2006 - Scientists developed a technology to increase the production of pharmaceuticals in plant cells. The technology forms the foundation for the new company SoluCel
PhD: Ghent University, Belgium, 1984
Principal Investigator VIB since 1998
Scientific Director since 2002
Laureat of the Körber Stiftung Prize
ISC highly-cited researcher in the field of plant and animal sciences
Laureate of the Francqui Prize
Five-yearly FWO-Excellence Prize: Prize Dr A. De Leeuw-Damry-Bourlart in Exact Sciences