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Root system development under drought stress
Svobodová, Barbora ; Soukup, Aleš (advisor) ; Fendrych, Matyáš (referee)
Plants actively react to the environmental conditions in such a way that they can use their resources efficiently and be resistant to suboptimal living conditions (e.g., high salinity, drought stress, high radiation, extremely high or low temperatures, insufficient nutrients etc.). One of the responses to drought stress (DS) is change in root system architecture (RSA). Optimized shape of RSA during drought stress can be under some situations "Steep, cheap and deep" ideotype. Steep - the roots grow in an angle ideally perpendicular to the soil surface. Cheap - most of the resources are spent on growing deeper while having small diameter and lots of aerenchym tissue. Plants with this RSA modulation try to reach deeper parts of the soil with greater water reservoirs and to achieve this, they use a wide range of mechanisms. Another change in RSA in reaction to drought stress, which directs the root to areas with more water is called hydrotropism. The key signal pathway which activates a large variety of drought responsive genes is the abscisic acid (ABA) pathway. Plants also have epigenetic mechanisms, which by remembering a stress factor they have already encountered, are capable of faster and more intensive response.
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