Rhizobium nod factors reactivate the cell cycle during infection and nodule primordium formation, but the cycle is only completed in primordium formation.

W.C. Yang, C. de Blank, I. Meskiene, H. Hirt, J. Bakker, A. van Kammen, H. Franssen, T. Bisseling

Research output: Contribution to journalArticleAcademicpeer-review

140 Citations (Scopus)

Abstract

Rhizobia induce the formation of root nodules on the roots of leguminous plants. In temperate legumes, nodule organogenesis starts with the induction of cell divisions in regions of the root inner cortex opposite protoxylem poles, resulting in the formation of nodule primordia. It has been postulated that the susceptibility of these inner cortical cells to Rhizobium nodulation (Nod) factors is conferred by an arrest at a specific stage of the cell cycle. Concomitantly with the formation of nodule primordia, cytoplasmic rearrangement occurs in the outer cortex. Radially aligned cytoplasmic strands form bridges, and these have been called preinfection threads. It has been proposed that the cytoplasmic bridges are related to phragmosomes. By studying the in situ expression of the cell cycle genes cyc2, H4, and cdc2 in pea and alfalfa root cortical cells after inoculation with Rhizobium or purified Nod factors, we show that the susceptibility of inner cortical cells to Rhizobium is not conferred by an arrest at the G2 phase and that the majority of the dividing cells are arrested at the G0/G1 phase. Furthermore, the outer cortical cells forming a preinfection thread enter the cell cycle although they do not divide.
Original languageEnglish
Pages (from-to)1415-1426
JournalThe Plant Cell
Volume6
DOIs
Publication statusPublished - 1994

Fingerprint

Dive into the research topics of 'Rhizobium nod factors reactivate the cell cycle during infection and nodule primordium formation, but the cycle is only completed in primordium formation.'. Together they form a unique fingerprint.

Cite this