Laser microdissection of cells and isolation of high-quality RNA after cryosectioning.

Laser capture microdissection (LCM) has become a powerful technique that allows analyzing gene expression in specific target cells from complex tissues. It is widely used in animal research, yet few studies on plants have been carried out. We have applied this technique to the plants-nematode interaction by isolating feeding cells (giant cells; GCs) immersed inside complex swelled root structures (galls) induced by root-knot nematodes. For this purpose, a protocol that combines good morphology preservation with RNA integrity maintenance was developed, and successfully applied to Arabidopsis and tomato galls. Specifically, early developing GCs at 3 and 7 days post infection (dpi) were analyzed; RNA from LCM GCs was amplified and used successfully for microarray assays.