Are microbes growing on flowers evil? Effects of old flower microbes on fruit set in a wild ginger with one-day flowers, Alpinia japonica (Zingiberaceae)

Abstract

Flowers are colonized by and inhabited by diverse microbes. Plants rapidly replace flowers of short lifespan, and old flowers senesce. This may contribute to avoiding adverse effects of the microbes. In this study, we investigate if the flower microbial community on old flowers impedes fruit and seed production in a wild ginger with one-day flowers. We inoculated newly opened flowers with old flower microbes, and monitored the effects on fruit and seed set. We also assessed prokaryotic communities on the flowers using amplicon sequencing. We found five bacterial amplicon sequence variants (ASVs) whose proportions were increased on the inoculated flowers. These ASVs were also found on flower buds and flowers that were bagged by net or paper during anthesis. Fruit set was negatively associated with the proportions of these ASVs, while seed set was not. The results suggest that old flowers harbor microbial communities different from those at anthesis, and that the microbes abundant on old flowers negatively affect plant reproduction. Though the short lifespan of flowers has gotten little attention, it might be an essential defense mechanism to cope with antagonistic microbes that rapidly proliferate on the flowers.

Stomatal and epidermal characteristics of Zingiberaceae in Serang District, Banten, Indonesia

“…Zingiberaceae consists of about 53 genera and 1,500 species around the world (Furmuly and Azemi 2020). The distribution of Zingiberaceae spread widely in tropical and subtropical areas of the world, such as Asia (Zahara 2020;Furmuly and Azemi 2020), China (Zhao et al 2022), Thailand (Kajornjit et al 2018), Malaysia (Salasiah and Meekiong 2018), Indonesia (Windarsih et al 2021), India (Pemba and Sharangi 2017), West Africa, South America (Kaliyadasa and Samarasinghe 2019), Brunei (Zaini et al 2014), Singapore, Philippines (Zahara 2020), Sri Lanka (Karunarathne et al 2021), Japan (Elvira et al 2022), Vietnam (Leong et al 2016 and Australia (Setiawan et al 2021).…”