Dr Josette Masle
Fellow
Environmental Biology
Research School of Biological Sciences
Building 46, RSBS Building
The Australian National University
ACT 0200 Australia
Personal WebsiteAddress : http://www.rsbs.anu.edu.au/profiles/masle.asp
Email: masle@rsbs.anu.edu.au
The Big Question
My general interest lies in the interplay between genetic and environmental determinants of growth and morphogenetic processes, in the temporal and spatial integration of these processes from cells to tissue and whole plant, and in the role of stress-induced root signals on meristems, leaf function and leaf:root coordination.
Short-Term Goals
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Molecular genetics and functional genomics of root mechanical stress. Our aim is to identify key genes and pathways involved in the sensing of mechanical stress by root tips and its direct effects on meristems, the anatomical and functional properties of roots and leaves, especially with respect to resource capture and water use. We combine gene expression studies, of single gene or genome-wide, mutant screening and genetic engineering, QTL analysis and physiological studies (Arabidopsis and wheat) under various stress patterns, using both in vitro and natural experimental systems.
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Interactions between endogenous and environmental mechanical forces in cell and plant development.We are studying these interactions in arabidopsis roots, and analysing their role in root morphogenesis and tropisms. (collaboration with Dr Geoff Wasteneys, UBC Vancouver)
- Root-Mychorrizal associations as a tool for improving plant nutrition under mechanical root impedance. By reducing root elongation, mechanical impedance increases the likelyhood of nutrient limitation to growth, especially for nutrients with low mobility such as P. We are investigating the extent to which mychorrizal associations may alleviate such risks, and affect the uptake capacity of mechanically impeded roots.
| Group (lab) Members and areas of research
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- Oliver Berkowitz, Postdoctoral fellow
- Ricarda Jost, Postdoctoral fellow
- Scott Gilmore, PhD student
- Joanna Maleszka, Technical Officer
- Josette Masle, Fellow, Head of lab
- 2 visiting scientists, from April (from Argentina and Israel )-
Current
- ANU and 2 external grants
Applications submitted or planned:
| Techniques in the Laboratory
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Currently active
- classic molecular techniques on RNA and DNA, Real-time quantitative PCR, protein isolation and expression, yeat 2 hybrid system, immunocytochemistry;
- Dissection and microscopy (light, cryostage, confocal)
- leaf and whole plant gas exchange techniques; mass-spectroscopy for measurements of natural isotopes in organic matter, CO 2 and water); elemental analysis;
- soil physics
In development
Top three areas of knowledge
- Abiotic Stress physiology ( especially drought and root mechanical impedance in their effects on growth, development, transpiration efficiency and root function)
- Gene expression and functional genomics of root stress (Arabidopsis and cereals)
- Root:shoot stress signalling
Top three technical skills
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Buer CS, Wasteneys GO, Masle J. 2003. Ethylene modulates root wave responses in Arabidopsis. Plant Physiology, (in press)
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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.
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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.
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Buer S, Masle J, Wasteneys GO. 2001 Growth conditions modulate root-wave phenotypes in Arabidopsis thaliana. Plant and Cell Physiology, 41:1164-1170.
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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.
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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.
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