Biosensing methods to assess environmental stress encountered by sugar beet
2001
Hermans, C. (Universite libre de Bruxelles (Belgium). Lab. de Physiologie et de Genetique Moleculaire des Plantes) | Chaerle, L. | Rodriguez, R.M. | Straeten, D. van der | Strasser, R.J. | Delhaye, J.P.
Light absorbed by photosynthetic pigments is used to drive photochemical reactions and consequently to insure plant growth. Moreover, the plant capacity to use light and to carry out photochemistry is limited and depends on several factors, including environmental stress leading the plant to suboptimality. The aim of this poster is to present some non-invasive methods which are probing the stress state by optical measurement in vivo. The pigments can be directly characterised by the reflected light which determines the colour of the leaf sample. Leaf reflectance allows to measure the sample without extracting the pigments. Light energy absorbed by the leaf is converted into chemical energy by photosynthesis or dissipated as heat or chlorophyll fluorescence. Therefore, the easily measurable fluorescence signal and the expressions derived from it, are strictly correlated to the photosynthetic events. More generally, the fluorescence behaviour of any plant changes continuously following its adaptation to a perpetually changing environment. The OJIP transient is a biophysical signal which is extremely rich in terms of information and reflects the time course of photosynthesis. As complementary information, fluorescence imaging offers a spatial visualisation of the pattern of dissipation processes of the light absorbed by the leaf. In addition, thermography imaging makes it possible to visualise the differences in the surface temperature pattern by detecting infrared radiation.
显示更多 [+] 显示较少 [-]