Polysaccharide biotechnology and responses of the sugarcane plant to the climatic changes
Our work with sugarcane focus on the carbohydrates, especially the cell wall polysaccharides, which can be used as a source of fibres that are important in food, paper and pharmaceutical technologies. These polymers are also important in energy production since the energy stored in the glycosidic linkages is quite high. Another research line in course aims the evaluation of the physiological, biochemical and molecular responses of sugarcane plants to an atmosphere with high CO2 concentration. In this line we expect to understand the responses of the plant to the future climatic changes. Below, we describe some of the work we have done and the main research lines that we are in course in our laboratory.
Polysaccharides and the problems in sucrose production
This line of work started when Prof. Gil Serra from UNICAMP brought us the challenge to understand why clogging was occurring during filtration of sugar in the end of the industrial process. We analysed the intermediary products and found that the problem is likely to be caused by beta-glucan, a mixed linkage beta-1,3-beta,1,4 glucan characteristic of grasses which has been shown to cause problems in beer production.
The SUCEST-FAPESP, the EST genome project
In 2001, we have searched for genes in sugarcane that are related to the cell wall. We found 469 of these genes in the databank. The digital northern showed that gene expression corroborates well with what is found in the walls. The literature for these data is in LIMA, D.U., SANTOS, H.P., TINÉ, M.A., MOLLE, F.D. & BUCKERIDGE, M.S. (2001) Patterns of expression of cell wall related genes in sugar cane. Genetics and Molecular Biology 24 (1-4): 191-198.
Characterisation of the cell wall polysaccharides of sugarcane
Following and extending the separation of tissues used in the SUCEST project, we performed cell wall fractionation and analysed the composition and structure of the cell walls of the whole plant. Our discoveries corroborated the findings of the genes mentioned above. A research paper that tells this story is under preparation. A PhD thesis was defended: Ana Maria da Silva. Distribuição e estrutura dos polissacarídeos de parede celular diferentes órgãos da cana de açúcar comparado a gramíneas do cerrado. 2001, CNPq. Tese (Biologia Celular e estrutural) - Universidade Estadual de Campinas. Cosupervised by Dr. Marcos P.M. Aidar. May 2005.
Responses of the sugarcane to high concentration of atmospheric CO2
We have performed experiments with sugarcane plants growing in Open Top Chambers (OTCs) supplied by the Centro de Tecnologia Canavieira (CTC) in Piracicaba. With these chambers, it is possible to keep artificially the concentration of CO2 so that plant growth and development can be followed in comparison with other OTCs in which the concentration is ambient (360ppm). When we doubled the concentration of the gas, the plants growing under 720ppm developed faster, producing a higher leaf area, number of leaves, roots and whole plant biomass. This indicates that sugarcane, although being a C4 plant, can sequestrate carbon quite intensely. At the moment, we are investigating the responses of gene expression using microarray analysis.
- LIMA, D.U., SANTOS, H.P., TINÉ, M.A., MOLLE, F.D. & BUCKERIDGE, M.S. (2001) Patterns of expression of cell wall related genes in sugar cane. Genetics and Molecular Biology 24 (1-4): 191-198.