Transcriptome analysis of lemon leaves (Citrus limon) infected by Plenodomus tracheiphilus reveals the effectiveness of Pseudomonas mediterranea in priming the plant response to mal secco disease

ABSTRACT

The use of biological control agents (BCAs) to cope with diseases has received considerable attention owing to its high efficiency and environmental safety. The aim of our study was to investigate the potential role of Pseudomonas mediterranea pretreatment in the response of lemon [Citrus limon (L.) Burm. f.] against mal secco, which is a devastating citrus disease caused by the fungus Plenodomus tracheiphilus. RNAseq analysis revealed that the fungus induced marked reprogramming of the transcriptome, but P. mediterranea pretreatment strongly reduced lemon leaf transcriptome modifications and limited the amount of fungal DNA inside the plant tissue. Furthermore, P. mediterranea prevented the downregulation of the genes involved in effector-triggered immunity (ETI) and the deregulation of genes involved in the biosynthesis and perception of the main phytohormones. To the best of our knowledge, this work represents the first report on the analysis of the P. tracheiphilus-lemon plant-BCA interaction at the molecular level.

KEYWORDS:

• Biocontrol agent
• mal secco
• Plenodomus tracheiphilus
• Pseudomonas mediterranea
• lemon
• transcriptome

Additional information

Funding

This research work was supported by the project ‘Sviluppo di induttori di resistenza a patogeni vascolari degli agrumi’ (S.I.R.P.A.) Misura 1.1.5 del PO FESR Sicilia 2014/2020 . The open access fee was not covered by the abovementioned project.

Notes on contributors

Angelo Sicilia

Angelo Sicilia, a Ph.D. researcher in plant genetics, department of agriculture, food and environment, University of Catania. He is an expert in transcriptomic and epigenetic studies of plants of agricultural interest subjected to abiotic and biotic stress.

Vittoria Catara

Vittoria Catara, Ph.D., an associated professor in plant pathology, department of agriculture, food and environment, University of Catania. Her studies are mainly devoted to plant-associated bacteria (plant pathogens and beneficial), their interaction with the host plant and the microbiome.

Giulio Dimaria

Giulio Dimaria, a Ph.D. in Biotechnology, University of Catania, is engaged in molecular studies targeting Pseudomonas spp. as biocontrol agents against plant pathogens and on microbial multispecies interactions within the plant host.

Emanuele Scialò

Emanuele Scialò, a Ph.D. Student, department of agriculture, food and environment, University of Catania. He is actually involved in transcriptomic analyses of the Citrus plant response to environmental challenges.

Marcella Russo

Marcella Russo, a Ph.D., Research and Services Agrobiotech Soc. Coop., Catania, Italy. She is a researcher in plant pathology responsible for the diagnostic laboratory.

Alessandra Gentile

Alessandra Gentile, a Ph.D., department of agriculture, food and environment, University of Catania. Her main interest is the genetic improvement of fruit trees by traditional and innovative methods (considerable expertise through biotechnological approaches).

Angela Roberta Lo Piero

Angela Roberta Lo Piero, a Ph.D., professor in plant genetics, department of agriculture, food and environment, University of Catania. She is an expert in the identification of transcriptome and epigenome modifications induced by both biotic and abiotic stresses, in particular, those related to climate changes.