One Protoplast Is Not the Other!

Plant protoplasts are often used as experimental material without paying attention to the tissue they are isolated from (a protoplast is a protoplast), whereas in other cases, they are considered not sufficiently able to reproduce the in planta situation. Here, we show that protoplasts are a very reliable experimental system, as long as we carefully chose their source. Transient transformation of protoplasts isolated from an adult tissue has been successfully used for developmental studies (Sheen, 2001), biochemical analysis (Sheahan et al., 2007), to examine the influence of hormones and stress factors (Meyer et al., 1984; Pasternak et al., 2002), to investigate cell wall regeneration (Leucci et al., 2007), to determine the subcellular localization of tagged proteins (Goodman et al., 2004), and to analyze protein interactions (Walter et al., 2004). Protoplasts represent a very convenient system as they can efficiently be transformed with several DNA constructs at the same time to study the colocalization and/or interactions of differently labeled proteins (Walter et al., 2004; Chen et al., 2006), and because they allow better imaging (higher resolution) compared to cells in an intact tissue.