The effects of the floral infection by a bacterial pathogen in a dioecious plant, Mallotus japonicus (Euphorbiaceae)

Maxime Marre*, Masayuki Ushio, Shoko Sakai

*Corresponding author for this work

Research output: Contribution to journalJournal articlepeer-review

2 Citations (Scopus)


Among all the different organs of a plant, flowers might have one of the most dynamic microbial communities, since many microbes are transmitted during flowering by insects and pollen. However, little is known about how these microbes affect floral characteristics and plant reproduction. Among the microbes transmitted to flowers, pathogens may have highly negative effects on plants' fitness. In this study, we investigated whether a bacterial pathogen, Erwinia mallotivora, occurs on flowers of the host plant Mallotus japonicus, and whether the transmission of the pathogen to flowers can result in systemic infection and/or reduction of fruit production. The pathogen has been reported to infect through leaves, while its ecology on flowers is unknown. We first confirmed the presence of the pathogen on flowers, indicating possible transmission by visitors or pollen. Then, we showed that the bacteria can infect the plant through flowers by inoculating the pathogen to both male and female flowers. Interestingly, the symptoms on leaves appeared earlier on the female plants than on the males. Besides, the inoculation significantly decreased fruit set of the female plants. Our results suggest a higher cost of infection in a female than in a male once the pathogen infected flowers. Although the effects of pathogen infection to flowers have rarely investigated in wild plants, it would be an interesting topic for future study if such sexual differences in the infection cost can cause sexual conflict and intraspecific adaptation load.

Original languageEnglish
Pages (from-to)231-239
Number of pages9
JournalPopulation Ecology
Issue number4
Early online date1 Feb 2022
Publication statusPublished - Oct 2023

Scopus Subject Areas

  • Ecology, Evolution, Behavior and Systematics

User-Defined Keywords

  • dioecious
  • Erwinia mallotivora
  • Mallotus japonicus
  • pollination
  • sexual conflict


Dive into the research topics of 'The effects of the floral infection by a bacterial pathogen in a dioecious plant, Mallotus japonicus (Euphorbiaceae)'. Together they form a unique fingerprint.

Cite this