Metagenomic insights from bacterial diversity of symptomatic and
asymptomatic leaves of ebony (Diospyros celebica Bakh.)
Abstract
The growing recognition of the importance of microbial communities in
shaping plant health and ecosystem function underscores the potential
value of metagenomic analysis for plant conservation. We analyzed the
bacterial diversity present in the leaves of ebony, a vulnerable species
endemic to Sulawesi, Indonesia and one of the most expensive woods
worldwide. The bacterial diversity was compared between symptomatic and
asymptomatic leaves from two developmental categories, young plants
(pole) and mature plants (tree). The microbial communities in
asymptomatic and symptomatic leaves of D. celebica were analyzed using
the 16S rRNA metagenomics to identify differences associated with the
fitness of D. celebica. The results showed that the contributing factors
to bacterial diversity in asymptomatic and symptomatic leaves were the
plant’s developmental stage, environmental conditions, and the severity
of pathogen attacks. Abundant bacteria at the phylum level across
samples were Proteobacteria, Actinobacteria, and Firmicutes, whereas at
the genus level were Sphingomonas, Jatrophihabitants, Bacillus,
Methylobacterium, and Methylocella. At the genus level, a higher
abundance of potentially beneficial bacteria was more evident in
symptomatic leaves than their asymptomatic counterparts, specifically
during the pole phase (young plant) than the tree phase (mature plant).
This suggests that plants, particularly the young ones, activate defence
mechanisms to ward off pathogen invasion by recruiting antipathogenic
bacteria to fortify their less developed defence systems than mature
plants. This research offers valuable insights into the potential roles
of bacteria in D. celebica fitness.