Lilith Weissflog (Universität Hohenheim)
Lilith Weissflog's Master thesis was awarded with the Prize for the Best Plant Science Master Thesis, which was carried out at Universität Hohenheim in the year 2024 with the title:
Effects of light cycle and air humidity on root exudates and water balance of maize (Zea mays L.)
Integration of the natural daily variation of relative humidity increased onset and intensity of drought stress in maize cultivated in climate chambers
Cultivation of maize is influenced by light and water availability. In the field, light and relative humidity change continuously throughout the day, but this phenomenon is usually not taken into account in experiments in climate chambers. In this master thesis, the effects of (1) light diurnal variation on root exudation and (2) relative humidity (rH) on the intensity of drought stress were investigated.
For this purpose, maize plants were grown in soil columns in a climate chamber for a period of three weeks and exposed to drought stress during the last 8 days. Light and rH were either kept constant during the day or modeled on the natural diurnal cycle.
The timing of root exudate collection influenced the exudation of carbon and dissolved carbohydrates, which increased at high light intensity, while the exudation of phenols remained constant. A diurnal variation in rH led to earlier and more intense drought stress compared to constant rH, as evidenced by early leaf curling. This effect was particularly pronounced in the rth3 mutant, which cannot form normal root hairs.
It is known that field trials on drought stress and trials in climate chambers often do not provide comparable results. The results of this master thesis clearly show that the influence of the rH diurnal cycle in particular should be given more consideration in future climate chamber studies.
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Lilith Weissflog conducted this work at the Institute for Crop Science 340e in the working group of Prof. Dr. Christian Zörb.