Tree species identity and leaf ageing alter the composition of
phyllosphere communities through changes in leaf traits
Abstract
Phyllosphere microorganisms are essential for plant growth and health,
notably through their action on nitrogen fixation and pathogens control.
However, whether and how the composition of phyllosphere communities
vary with plant traits and leaf age remain still unclear. We used
high-throughput sequencing to explore the phyllosphere microbial
diversity and composition communities in needles of different ages
(i.e., originating from different cohorts) for three evergreen
coniferous species (Pinus koraiensis, Picea asperata and Abies fabri).
We then assessed the relationships between the composition of
phyllosphere microorganisms and needle traits. The results showed that
needle age explained relatively well the phyllosphere microbiome α
diversity, whereas tree species identity explained the phyllosphere
microorganisms β diversity. The changes in the composition of
phyllosphere microbial communities between newly-formed and perennial
needles were greatest in Pinus koraiensis. Overall, Cyanobacteria and
Gammaproteobacteria were dominant in newly-formed needles. Plant traits
such as leaf dry matter content (LDMC), leaf mass per area (LMA) and
total phosphorus content (TP) were the main predictors of phyllosphere
community. Our results provide new insights into the mechanisms of
community assembly among different evergreen tree species and provide a
better understanding of the interactions between plant traits and
phyllosphere microorganisms during needle ageing.