Project 2 - Growth stage-based phenotypic analysis of Arabidopsis mutants defective in enzymes of central metabolic pathways
Many studies of the phenotypic effects of enzyme mutations or deletions in arabidopsis are confined to vague, qualitative comments about size and shape of the mature plant and the most extreme effects on rate of development. A recent paper (Boyes et al. (2001) Growth stage-based phenotypic analysis of arabidopsis: a model for high throughput functional genomics in plants. Plant Cell 13, 1499-1510) has proposed a systematic approach for obtaining quantitative data at defined developmental stages over the entire life cycle of the plant. The approach consists of two "platforms". The first platform characterises early seedling growth during axenic culture on vertical plants of agar for up to two weeks. The second platform involves extensive measurements from plants grown in soil for about two months.
The aim of this project is to examine the practicality and utility of this systemic approach for identifying growth defects and/or developmental perturbations in arabidopsis lines possessing lesions in know enzymes of primary metabolism. The project is likely to be confined to analysis using the first platform which will confine individual studies to a two-week period. This has two advantages: (i) the timetabling commitment for a complete analysis (i.e. over 9 weeks) is probably unreasonable since the analyses require daily inspection of the plants; (ii) the shorter period for analysis will allow multiple independent growth analyses to be completed over one academic term. The precise mutant lines examined in the project will depend on the availability of novel mutants being generated in the group but are likely to include "knockout" mutants lacking the triose-phosphate translocator and phosphoenolpyruvate translocator (responsible for exchange of intermediates between plastids and the cytosol), ADPglucose pyrophosphorylase (necessary for starch synthesis) and sucrose synthase (involved in sucrose metabolism). The effects of these mutations will be recorded by digital imaging and assessed by morphometric analysis. This project offers the opportunity to help develop the foundations for a generally applicable approach to the critical characterisation of mutant lines, and requires a reliable researcher with the ability to conduct careful, methodical analysis. Again, generating data should be easy - the value of this project will be in the reliability of the information that is produced, this will require precision in data collection and rigour in record keeping.