Exploring the Interaction between Phytophthora palmivora and Oil Palm through Gene Co-expression Network Analysis

Phytophthora palmivora, the causal agent of Bud Rot (BR) in oil palm (Elaeis guineensis
Jacq.), is responsible for significant crop losses in Colombia, affecting over 145,000
hectares in the last decade. Recent advancements have improved our understanding of
P. palmivora's virulence mechanisms and host resistance. However, several unknown
aspects remain, particularly concerning the oil palm host. In a transcriptomic study by
Avila-Mendez et al. (2019), the interaction between P. palmivora and oil palm was
investigated through a transcriptomic approach, with a focus on susceptible (Clon57)
and resistant (Clon34) oil palm genotypes. Using RNAseq data from this study, we aimed
to construct gene co-expression networks for both the pathogen and oil palm during
compatible and incompatible interactions. Through this approach, we identified coexpressed
gene hubs in P. palmivora that may play important roles during oil palm
infection. Additionally, we observed signs of pathogen manipulation in susceptible oil
palm materials, triggering an exaggerated response and compromising the
phenylpropanoid pathway. In contrast, resistant oil palm materials demonstrated control
over their response through putative Heat Shock Proteins (HSP), maintaining a balance
between primary metabolism and biotic defense. Overall, this study provides insights
into the molecular mechanisms underlying the interaction between oil palm and P.
palmivora, which can contribute to the effective control of Bud Rot.