ABSTRACT
Lateral roots (LRs) as defined here are those that originate from some other root. This means that the lateral roots can be derived either from a seminal root, an adventitious root, or another lateral root. The lateral roots, therefore, constitute almost the whole root system. They influence many aspects that are so important for the plant’s development as its adaptability to the environment and its absorption capacity. Lateral roots affect plant size, plant production, vitality, etc. All these aspects justify the scientific interest that the study of lateral roots has always earned. Moreover, in many plants the lateral roots originate far from the apex. Therefore, cell proliferation during lateral root development does not overlap the cell proliferation of the apical meristem. The two processes are temporally and spatially separated. In these plants, the analysis of lateral roots is more relevant because these roots originate from a very few parent cells, called founder cells, which are very long and highly vacuolated mature cells. These cells proliferate and give rise to very short derivative cells, which are nearly isodiametric, with thinner cell walls, a marked increase in cytoplasmic basophilia and volume, a pronounced nucleolar enlargement, and numerous small vacuoles. These short cells show the typical morphological features of meristematic cells, suggesting that the founder cells undergo a dedifferentiation process.
