Our central interest is on the interplay between genetic and environmental determinants of plant development and adaptation to stress. We are studying how plants sense their environment and integrate endogenous controls and environmental cues to modulate their shape, size and architecture, and make optimum use of available resources for growth and survival.
Our research combines molecular biology and genetics, developmental biology and physiology, and uses both directed genetic manipulation and natural genetic diversity approaches, in developmentally and evolutionary diverse species, including Arabidopsis and rice, but also tomato or the polyploidy bread wheat.
Roots as environmental sensors and signalling agents to aerial meristems, expanding leaves and stomata.
Roots have evolved sensitive mechanisms for sensing variations in their environment and effective local and long-distance signalling mechanisms. We study the sensing and signalling of root mechanical stress, a condition inevitably associated with soil drought. We examine the developmental and functional responses it triggers in roots and leaves. We have identified a range of mechano-sensitive genes that fall in a range of functional groups including signalling, trafficking, meristem function, root development, carbon metabolism and wall synthesis.
We are currently investigating the function of genes regulating meristem function, synthesis of cellular membranes, intercellular and inter-organ signalling, as well as a gene family regulating cross-talk between biotic and abiotic stress. Prominent among those genes are components of kinase cascades, and regulators of phospholipid synthesis.
Leaf patterning, leaf surface characteristics and epidermis-mesophyll communication for optimal trade-off between CO2 gain and water loss.
Water is the single most limited resource, globally. Carbon assimilation by plants incurs water costs. As CO2 enters the leaf through stomata, water vapour escapes. We are studying central components of genetic pathways controlling leaf patterning, leaf surface characteristics and epidermis-mesophyll communication for optimal trade-off between CO2 gain and water loss..
When challenged by variations in their environment plants often seem to coordinate photosynthesis and transpiration, but there is genetic variation in that coordination both inter and intra species. While this has been recognised for years, the underlying genes are mostly unknown. We are investigating candidate genes, originally identified through screen of arabidopsis and tomato recombinat and introgression lines.
Germinate or remain quiescent?
Seed germination is a crucial developmental check point that initiates a new life cycle. Its appropriate timing is a condition of successful seedling establishment, plant propagation and competitiveness, and usefulness as a source of food.
In a recent genetic screen we looked for mutants altered in the perception of abiotic stress during germination in an attempt to discover genes involved in signalling environmental variation to the seed compartments - protective seed envelopes, embryo nourishing tissues, embryo itself- and modify the intricate interactions between these compartments that germination absolutely requires. Through that screen, we isolated a set of novel seed germination genes, and generated genetic material enabling investigation of their mechanisms of action and of the molecular pathways they operate in.
Special Project Student
Open to students
Cross-talk between abiotic and biotic stress signaling (Undergraduate, Honours, Graduate, Higher degree by research)
A candidate gene linking root development and stomatal physiology (Undergraduate, Honours, Graduate, Higher degree by research)
Abiotic stress signalling, developmental programming and plant adaptation (Undergraduate, Summer scholar course, Honours, Graduate, Higher degree by research)
Genes from wild relatives to improve drought resistance: case study on tomato (Summer scholar course, Honours, Graduate)
Germinate or remain quiescent? (Undergraduate, Summer scholar course, Honours, Higher degree by research)
The leaf epidermis: optimizing defense, water loss and CO2 entry (Undergraduate, Summer scholar course, Honours, Graduate, Higher degree by research)
The role of phospholipids and lipid signalling in the plasticity of growth and development (Summer scholar course, Honours, Graduate, Higher degree by research)
The sensing and signalling of mechanical stress by roots- Genetic regulation of root: shoot communication and function under drought (Summer scholar course, Honours, Higher degree by research)
- Cazzonelli CI, Vanstraelen M, Yin K, Carron-Arthur A, Nisar N, Tarle G, Cuttriss AJ, Searle IR, Simon S, Benkova E, Mathesius U, Masle J, Friml J, Pogson BJ. 2013. Role of the Arabidopsis PIN6 auxin transporter in auxin homeostasis and auxin-mediated development. PlosOne
- Yun-Kuan Liang, Xiaodong Xie, Shona E. Lindsay, Yi Bing Wang, Josette Masle, Lisa Williamson, Ottoline Leyser and Alistair M. Hetherington. 2010. Cell wall composition contributes to the control of transpiration efficiency in Arabidopsis thaliana. The Plant Journal
- Jost R, Berkowitz O, Shaw JE, Masle J. 2009. Biochemical characterisation of two wheat phosphoethanolamine N-methyltransferase isoforms with different sensitivities to inhibition by phosphatidic acid. Journal of Biological Chemistry, 284, 46:31962-31971.
- Berkowitz O, Jost R, Pollman S and Masle J. 2008. Characterisation of TCTP, the translationally controlled Tumor Protein, from Arabidopsis thaliana. Plant Cell, 20:3430-3447.
- Hoque MS, Masle J, Udvardi MK, Ryan PR, Upadhyaya NM. 2006. Over-expression of the rice OsAMT1-1 gene increases ammonium uptake and content, but impairs growth and development of plants under high ammonium nutrition. Functional Plant Biology, 33:153-163.
- Masle J, Gilmore SR, Farquhar GD. 2005 The ERECTA gene regulates plant transpiration efficiency in Arabidopsis. Nature, 436, 866-870
- Buer CS, Wasteneys GO, Masle J. 2003. Ethylene modulates root wave responses in Arabidopsis. Plant Physiology, in press
- Kaiser BN, SR Rawat, Siddiqi MY, Masle J, Glass AD 2002. Functional analysis of an Arabidopsis t-DNA "knock-out" of the high-affinity NH4+ transporter AtAMT1;1. Plant Physiology, 130: 1263-1275.
- Masle J. 2002 Root impedance and plant performance- Physiology, Genetic determinants. In: Plant Roots, The Hidden Half (3rd edition) Y. Waisel, A. Eshel, U. Kafkafi eds, Marcel Dekker, Inc. Publ, NewYork, 807-819.
- Buer S, Masle J, Wasteneys GO. 2001 Growth conditions modulate root-wave phenotypes in Arabidopsis thaliana. Plant and Cell Physiology, 41:1164-1170.
- Masle J. 2000. The effects of elevated [CO2] on cell division rates, growth patterns and blade anatomy in young wheat plants are modulated by factors related to leaf position, vernalisation and genotype. Plant Physiology, 122:1399-1415.
- Masle J. 1999. Root impedance: sensing, signalling and physiological effects. In: Plant responses to environmental stresses: From phytohormones to genome reorganization. H.R. Lerner ed., M. Dekker, Inc., New York Publ., Chapter 22, pp 476-495.
- Masle J. 1998. Growth and stomatal responses of wheat seedlings to spatial heterogeneity of mechanical resistance to root penetration in wheat. Case of bi-layered soils. Journal of Experimental Botany, 49:1245-1257.
- Beemster, GTS, Masle, J, Williamson, RW and Farquhar, GD 1996. Effects of soil resistance to root penetration on leaf expansion. Journal of Experimental Botany, 47, 1663-1678.
- Masle J, Badger MR, Hudson GS. 1993. Effects of ambient CO2 concentration on growth and nitrogen use in tobacco (Nicotiana tabacum) plants transformed with an antisense gene to the small subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase. Plant Physiology, 103, 1075-1088.
- Masle, J 1992. Will plant performance on soils prone to drought or with high mechanical impedance to root penetration be improved under elevated atmospheric carbon dioxide? Australian Journal of Botany 40, 491-500.
- Masle, J and Farquhar, GD 1988. Effects of soil strength on the relation of water use efficiency and growth to carbon isotope discrimination in wheat seedlings. Plant Physiology 86, 32-38.