Plastid biology and the interaction between plastids and leaf development. Plastid differentiation into different plastid types in different tissues within plants. Stromules; thin tubules containing stroma which emanate from plastid bodies and are currently of unknown function. Petal development and the role of chromoplasts in pigmentation. Tomato fruit development and the interconversion of chloroplasts and chromoplasts.
I convene four undergraduate modules which teaches plant science and eukaryotic cell biology to in excess of 500 students each year.
Whole Organism Biology and Plant Science are both first year modules in which one tries to interest and inspire students in to the ways of plants, both through lectures and practicals.. The Dynamic Cell is a second year module which is very popular and covers basic eukaryotic cell biology in plants and animals, with emphasis in making the teaching dynamic. I use many video clips to illustrate how dynamic cellular processes are.
Plants and the Light Environment is a final year module which covers in depth, aspects of light and photosynthesis, leaf and plastid development and photosynthetic strategies such as C3 and C4.
I also organise final year undergraduate projects in the Plant and Crop Sciences Division.
I am interested in a variety of developmental topics in plant biology centred around the development of plastids and the development of leaves, petals and fruit. My work has used the model plant… read more
PYKE KA, 2013. Divide and shape: an endosymbiont in action Planta: Special Issue on Evolution and Biogenesis of Chloroplasts and Mitochondria. 237, 381-387 SMILLIE, I.R.A., PYKE, K.A. and MURCHIE, E.H., 2012. Variation in vein density and mesophyll cell architecture in a rice deletion mutant population Journal of Experimental Botany. 63(12), 4563-4570
PYKE K and LEECH R, 2010. Genetic analysis of plastid division and expansion in Arabidopsis. Plant Physiology: Classic Collection. 54, 1–2
I am interested in a variety of developmental topics in plant biology centred around the development of plastids and the development of leaves, petals and fruit. My work has used the model plant system Arabidopsis thaliana and tomato to address questions about chloroplast development and its interaction with leaf development. A major aspect of our research has been investigating the molecular basis for the control of chloroplast division in Arabidopsis and higher plants in general. Using mutants which we have isolated in Arabidopsis which have significantly reduced numbers of chloroplasts per cell, a greater understanding of the molecular mechanisms which control plastid divsion has been achieved.
The differentiation of chloroplasts into chromoplasts in tomato fruit is an horticulturally important process which occurs during fruit ripening and we have studied several aspects of the cell biology of this process. In particular analysis of the suffulta mutant in tomato, which has giant chloroplasts in cells of its green tissues, has shown that these giant chloroplasts fragment and produce vesicles during their differentiation into chromoplasts. As a result of this process, suffulta fruit have a normal complement of chromoplasts. We are currently trying to determine the nature of the suffulta mutation.
Other projects using tomato and tobacco are centred on understanding the role of plastid stromules in root and fruit plastid function. Stromules are long thin tubules which arise from the plastid body and contain stroma but no thylakoid membrane or chlorophyll. We have examined their behaviour during tomato fruit cell ripening and showed that they are much more abundant in fully ripe cells containing chromoplasts than in immature cells containing chloroplasts. During tobacco hypocotyl elongation, stomule length increases as plastids become less densely packed suggesting that they may play a role in plastid density sensing. Another interest is the differentiation of plastids in roots, in particular those that form as amyloplasts in the columella cells, which facilitate gravity sensing by roots. We are using plastid-targeted GFP in order to examine the development of these cell specific plastids.
In association with Erik Murchie and Ian and Julie King, we are currently exploring variation in chloroplast compartment size, cell morphology and photosynthesis in a range of alien introgression lines of wheat.
Also in association with Erik Murchie, we are studying the leaf development in rice and examining how cell morphology and chloroplast development occur during rice leaf expansion.