Necrotrophism Is a Quorum-Sensing-Regulated Lifestyle in Bacillus thuringiensis

PLoS Pathogens

Didier Lereclus¹  Stéphane Perchat¹  Christophe Buisson¹  Christelle Lemy¹  Nalini Ramarao¹  Thomas Dubois¹  Christina Nielsen-LeRoux¹  Michel Gohar²  Philippe Jacques³  Anne-Brit Kolstø⁴  Karoline Faegri⁴ 

[1] INRA, UMR1319 Micalis, La Minière, Guyancourt, France;INRA, UMR1319 Micalis, Thiverval-Grignon, France;ProBioGEM, UPRES EA 1026, Université Lille Nord de France, USTL, Villeneuve d'Ascq, France;School of Pharmacy, Laboratory for Microbial Dynamics, University of Oslo, Oslo, Norway

关键词: Insects;    Bacterial spores;    Bacillus;    Gene expression;    Larvae;    Toxins;    Biofilms;    Quorum sensing;   

DOI  :  10.1371/journal.ppat.1002629

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

How pathogenic bacteria infect and kill their host is currently widely investigated. In comparison, the fate of pathogens after the death of their host receives less attention. We studied Bacillus thuringiensis (Bt) infection of an insect host, and show that NprR, a quorum sensor, is active after death of the insect and allows Bt to survive in the cadavers as vegetative cells. Transcriptomic analysis revealed that NprR regulates at least 41 genes, including many encoding degradative enzymes or proteins involved in the synthesis of a nonribosomal peptide named kurstakin. These degradative enzymes are essential in vitro to degrade several substrates and are specifically expressed after host death suggesting that Bt has an active necrotrophic lifestyle in the cadaver. We show that kurstakin is essential for Bt survival during necrotrophic development. It is required for swarming mobility and biofilm formation, presumably through a pore forming activity. A nprR deficient mutant does not develop necrotrophically and does not sporulate efficiently in the cadaver. We report that necrotrophism is a highly regulated mechanism essential for the Bt infectious cycle, contributing to spore spreading.

【 授权许可】

CC BY