Genetyczne podłoże oddziaływań bakterii endofitycznych z roślinami

Genetic basis of endophytic bacteria-plant interactions
A. Piński, K. Hupert - Kocurek

1. Wprowadzenie. 2. Genetyczne uwarunkowania kolonizacji rośliny przez endofity bakteryjne. 3. Genetyczne podłoże odporności bakterii endofitycznych na stres oksydacyjny i osmotyczny. 4. Mechanizmy sekrecji i translokacji białek efektorowych. 5. Czynniki transkrypcyjne zaangażowane w interakcje endofit bakteryjny-gospodarz. 6. Zmiany w ekspresji genów w interakcji endofit bakteryjny-roślina. 7. Podsumowanie

Abstract: Bacterial endophytes promote plant growth through colonization of the internal tissues of the plant without external signs of infection or negative effects on their host. Although endophytic bacteria enter the plant through the primary and lateral root hair cells, root cracks and wounds, they are found at many sites in the plants, such as stems, leaves, seeds, and xylem. The colonization of plant tissues comprises: host recognition, chemotactic migration of endophyte towards root exudates, adhesion to the surface of the root, penetration of the epidermidis and finally adaptation to a new environment. The distinctive features of endophytic bacteria are their flagellar motility, secretion of the cell-wall degrading enzymes (CWDEs) and biofilm-forming ability. It is postulated that endophytic bacteria capable of colonizing plants should contain at least a minimum set of genes responsible for their endophytic behavior. Among them, genes involved in chemotaxis and adhesion processes, secretion and translocation of effector proteins as well as genes which facilitate survival in reactive-oxygen rich environment can be distinguished. An important group of genes are the ones which encode regulatory proteins involved in the control of gene expression at the transcriptional level. However, in establishing an endophytic association with plants, species-specific gene-functions seem to be involved. Identification of genes responsible for endophytic behavior will increase our knowledge about the genetic aspects of plant-endophyte interactions and enable to fully exploit their potential.

1. Introduction. 2. Genetic determinants of plant colonization by bacterial endophytes. 3. The genetic basis of endophytic bacteria resistance to oxidative and osmotic stress. 4. Mechanisms of secretion and translocation of effector proteins. 5. Transcription factors involved in the interactions of bacterial endophytes with the host. 6. Changes in gene expression in the plant-endophyte interactions. 7. Summary