Department of Agricultural and Food Sciences, Alma Mater Studiorum-University of Bologna, 40127 Bologna, Italy.
Research and Innovation Centre, Fondazione Edmund Mach, 38010 San Michele all'Adige, Italy.
Int J Mol Sci. 2021 Apr 22;22(9):4375. doi: 10.3390/ijms22094375.
Ethylene interacts with other plant hormones to modulate many aspects of plant metabolism, including defence and stomata regulation. Therefore, its manipulation may allow plant pathogens to overcome the host's immune responses. This work investigates the role of ethylene as a virulence factor for pv. (Psa), the aetiological agent of the bacterial canker of kiwifruit. The pandemic, highly virulent biovar of this pathogen produces ethylene, whereas the biovars isolated in Japan and Korea do not. Ethylene production is modulated in planta by light/dark cycle. Exogenous ethylene application stimulates bacterial virulence, and restricts or increases host colonisation if performed before or after inoculation, respectively. The deletion of a gene, unrelated to known bacterial biosynthetic pathways and putatively encoding for an oxidoreductase, abolishes ethylene production and reduces the pathogen growth rate in planta. Ethylene production by Psa may be a recently and independently evolved virulence trait in the arms race against the host. Plant- and pathogen-derived ethylene may concur in the activation/suppression of immune responses, in the chemotaxis toward a suitable entry point, or in the endophytic colonisation.
乙烯与其他植物激素相互作用，调节植物代谢的许多方面，包括防御和气孔调节。因此，其操纵可能允许植物病原体克服宿主的免疫反应。这项工作研究了乙烯作为 pv 的毒力因子的作用。（Psa），猕猴桃细菌性溃疡病的病原体。这种病原体的流行、高毒力生物型会产生乙烯，而在日本和韩国分离的生物型则不会。乙烯的产生在植物体内受到光/暗周期的调节。外源乙烯的应用刺激了细菌的毒力，如果在接种前后进行，分别限制或增加了宿主的定植。一个与已知细菌生物合成途径无关且推测编码氧化还原酶的基因的缺失，会消除乙烯的产生并降低病原体在植物体内的生长速度。Psa 产生的乙烯可能是与宿主进行军备竞赛中最近独立进化的一种毒力特征。植物和病原体来源的乙烯可能在激活/抑制免疫反应、向合适的进入点趋化或内生定植方面协同作用。
