Effects of sugars on the rhizoid development of the lower plant, Marchantia Polymorpha

Abstract

Marchantia polymorpha is a bryophyte and is a lower plant compared to the angiosperm Arabidopsis thaliana. This makes it a good model to study the evolution of early plants. Marchantia has rhizoids instead of roots which is hypothesised to be the equivalent to the root hairs of a true plant. Glucose has been shown to increase root length and the number of root hairs in Arabidopsis. Glucose is also known to regulate genes affected by the phytohomone indole-acetic acid, IAA. It is of interest to observe if sugars and phytohormones are capable of influencing the rhizoid development in marchantia as it may suggest that these features are conserved. Marchantia thalli were grown in media with different sugars, increasing sucrose concentration and a mixture of sucrose and phytohormones. Our studies show that sucrose, glucose and maltose promote rhizoid growth. Rhizoid formation also observed with increasing concentrations of sucrose. Inhibiting IAA biosynthesis using 5-methyl-tryptophan resulted in reduced rhizoid formation even in the presence of high concentrations of sucrose. This suggests that there is a link between sugars and the Phytohormone IAA.