FRIML, J., BENFEY, P., BENKOVÁ, E., BENNETT, M. D., BERLETH, T., GELDNER, N., GREBE, M., HEISLER, M., HEJÁTKO, J., JÜRGENS, G., LAUX, T., LINDSEY, K., LUKOWITZ, W., LUSCHNIG, Ch., OFFRINGA, R., SCHERES, B., SWARUP, R., TORRES-RUIZ, R., WEIJERS, D., ZAŽÍMALOVÁ, Eva. Apical–basal polarity: why plant cells don't stand on their heads. Trends in Plant Science. 2006, 11(1), 12-14. ISSN 1360-1385. E-ISSN 1878-4372.

The paper deals with the two different terminologies used to describe the orientation and polarity in the plant body. Anatomical terminology uses the term base for the root-shoot junction and both shoot and roots tips are considered as apices. In contrast to this, embryologic terminology defines the root embryo pole as the base and the opposite end as the apex. From „apex“ and „base“, the directional terms “apical” and “basal”, as well as “acropetal” and “basipetal” are derived and, therefore, the definition of apex and base is crucial. For post-embryonic development, the usage of the anatomical terminology is suggested but for the description of polarity of individual cells the embryological terminology seems to be more convenient. As a simplification, the intuitive terms „upper“ and „lower“ are suggested. Anyway, in each report it should be clearly stated which terminology is used.