## 1 Introduction  
Actin and tubulin are major structural components of the cytoskeleton, and their polymerization and depolymerization are important, amongst other things, for cytoplasmic streaming and intracellular trafficking [1]. Soon after the discovery of actin, it was shown that oxidizing agents not only inhibited the polymerization of globular actin, but also depolymerized actin filaments [2]. The importance of sulfhydryl groups for protoplasmic streaming in plant cells was reported in 1964 by [PERSON] [3] who showed the effect of the specific thiol-trapping reagent \(p\)-chloromercuribenzoate in bringing cytoplasmic streaming to a standstill in the internodal cells of _Nitella flexilis_, the leaf cells of _Elodea densa_, the root hair cells of _Hydrocharis morsus raane_, and the stamen hair cells of _Tradescantia reflexa_. Elements of the cytoskeleton are known to be highly sensitive to oxidation [4, 5], and redox-mediatedposttranslational modifications of the cytoskeleton affect polymerization [6; 7]. The redox regulation of actin and tubulin dynamics is now a well characterized phenomenon [8; 9; 10]. Allicin from garlic is the most prominent sulfur-containing bioactive compound in freshly damaged garlic tissue [11; 12]. It oxidizes thiol-groups in a thiol-disulfide-exchange-like manner, leading to S-thioallylated adducts [13; 14; 15; 16; 17]. Since allicin is a strongly antimicrobial compound with a broad-spectrum of activity, it has the potential for application in agricultural pest control [18; 19; 20; 21; 22]. Allicin's degradation products, primarily polysulfanes, ajoenes, and vinyldithins, can also show biological activity and can be active as antimicrobial components. The effect of these sulfur-containing components in allelopathic interactions with other organisms can be of importance, as is observed in particular for wild garlic (_Allinum ursinum \(\mathrm{L}\)_), to which is attributed the exudation of sulfur-containing secondary metabolites [23]. In animal cells, it was shown that allicin, which acts as a \"redox-toxin\" [13], affects the integrity and function of the cytoskeleton [24]. It was reported that 0.5 \(\upmu\)M of allicin preferentially affected the tubulin cytoskeleton, while the actin cytoskeleton was a minor target (ibid.). However, at a higher 25 \(\upmu\)M concentration of allicin, the actin cytoskeleton was also reported to be disrupted [25]. Furthermore, 16 cytoskeletal proteins were shown to be S-thioallylated by 100 \(\upmu\)M of allicin in human Jurkat cells within 10 min of exposure [26]. The actin cytoskeleton is of particular importance for the correct polar transport of auxin in relation to PIN efflux carrier recycling [27; 28; 29]. Auxin also exerts an influence on the regulation of actin turnover [30]. The high redox sensitivity of actin is probably significant for the observation that auxin transport is related to the state of the total cellular glutathione pool, which is the most important thiol-based redox buffer of the cell [31]. Thus, treatment of _Arabidopsis thaliana_ seedlings with buthionine sulphoximine (BSO), a specific inhibitor of glutathione biosynthesis, led to a clear concentration-dependent inhibition of root growth and a loss of the auxin efflux carriers PIN1, PIN2, and PIN7, as well as the consequent destruction of the correct auxin distribution in the root tip (ibid.). This observation correlates with the finding that mutants in glutathione biosynthesis formed shortened roots, such as was seen in the weak allele mutants _pad2_ and _cad2_ of the _Arabidopsis thaliana GSH1_ gene, which had reduced glutathione levels [32]. Mutants of the strong rml1 (root meristemless) allele of _GSH1_ were almost unable to produce glutathione, could not maintain the root apical meristem, and consequently could not form a root [33; 34].