Transcriptomics of lateral root initiation in Maize

We developed a method to synchronize the induction of lateral roots in primary and adventitious roots of Zea mays, and used it to perform a genome-wide transcriptome analysis of the pericycle cells in front of the phloem poles during lateral root initiation. Lateral roots were induced in primary and adventitious roots of Maize. For the primary root, plants were germinated and grown 64 hours in NPA 50 µM, and then transfered to NAA 50 µM. For the adventitious roots, plants were germinated and grown in water for 6 days, then tranfered 4 days in NPA 25 µM, and finally transfered to NAA 25 µM. For all these roots, pericycle cells located in front of the phloem poles in segments of roots located between 5 and 10 mm distance from the root tip were isolated using laser capture microdissection after cryosection. Material was sampled at 0 hours (NPA) and after 2, 3 and 4 hours of NAA treatment, for both the primary and adventitious roots and also after 6 hours and 9 hours of NAA treatment for the adventitious roots.