0 avis
Dynamic cell wall modifications associated with early rhizobial infection thread development in Medicago truncatula
Archive ouverte
Edité par CCSD -
International audience. The development of nitrogen-fixing root nodules in legumes requires coordinated nodule organogenesis and micro-symbiont colonization. In temperate legumes, the controlled entry of symbiotic rhizobia into roots is a crucial step, which starts in root hairs (RHs). Colonization proceeds via unique host-constructed tubular structures, known as infection threads (ITs) that form by polar growth from a globular infection chamber [1-3]. To follow the formation of ITs that occurs at non-synchronous infection sites, we have adopted a live plant imaging approach targeting individual infection sites, which is suitable to get access to the transient stages of IT elongation within RHs as well as the preparation of outer cortical cells for cell-to-cell progression of infection. In contrast to the well-known, easy-to-spot, fully developed ITs filled with numerous colonizing rhizobia confined within a rigid cell wall/matrix environment, early tip growing ITs are inconspicuous, thin structures immerged in active cytoplasm and contain a limited number of rhizobia which are able to grow and move in a gel-like matrix[1,4-5]. In order to understand the complex dynamics of IT formation and maturation we have focused our work on these early tip-growing ITs. Host proteins associated to the rhizobial colonization process, including novel actors identified via transcriptomic approaches, are now being used as fluorescent protein fusions to characterize cell wall-related and other responses underlying the early stages of rhizobial (Sinorhizobium meliloti) IT development and outer cortex cell reprogramming in Medicago truncatula.References 1.Gage (2004). Microbiol Mol Biol Revl, 68, 280-300.2.Fournier J et al (2008). Plant Physiol, 148, 1985-1995.3.Fournier J et al (2015). Plant Physiol, 167, 1233-1242.4.Brewin NJ (2004). Crit Rev Plant Sci 23, 293-316.5.Tsyganova AV, Brewin NJ, Tsyganov VE (2021). Cells, 10, 1050.
Consulter en ligne
Suggestions
Du même auteur
