Table 1.

Method for delivering an oligonucleotide to a plant cell.

Method	Tissue Type/Developmental Stage	Advantages	Disadvantages
infiltration under reduced pressure [11,12]	almost any type of tissue and any stage of development: whole plant, leaves, roots	quick and easy to perform method, many plants can be infiltrated at the same time, spiking is possible to a certain extent (easy to seedlings)	considerable stress, a large volume of oligonucleotide solution is needed at once and tissue residues contaminate the tissue, it is difficult to transfer the method to adult plants
infiltration through the stomata [53]	leaves only (the larger the better), best results with mature leaves, possible study in vivo	small volumes of the oligo solution required at once, no problem with impurities, no equipment required	more variable results, possibility of tissue damage, more difficult to do manually, especially troublesome with some small-leaved species such as flax
spraying the cells/tissue [43]	different developmental stages and organs, possible life examination for above-ground part of the plant only	simple scale-up, hardly any equipment required	more variable results, more difficult to control quantitative application of oligo
uptake in a sugar solution [17,24,25,43]	whole plant, leaves, roots, best results with seedlings, possible study in vivo	quick and easy to perform method, hardly any equipment re-quired	large volume of oligonucleotide solution is needed at once, it is difficult to transfer the method to adult plants