Journal Article

Integrated proteomic and transcriptomic analyses of Citrus australasica in response to Candidatus Liberibacter asiaticus infection

Pang, Qiuling, Wu, Xiaoxiao, Wang, Xuefeng, Chen, Chuanwu, Fang, Haimeng, Feng, Jing, Han, Yang, Lou, Binghai, Deng, Chongling, Zhang, Feng, Li, Hongbing

2025

Overview

Background Candidatus Liberibacter asiaticus ( C Las) is the most prevalent pathogen causing the globally prevalent citrus Huanglongbing (HLB). The citrus relative Citrus australasica F. Muell. shows tolerance to HLB. In this study, we grafted HLB-tolerant Ca (C. australasica) and HLB-susceptible Cs ( C. sinensis) Osbeck branches onto healthy C. reticulate Blanco ‘Shatangju’ (SH) and C Las-infected (SI) rootstocks. Results To understand HLB tolerance mechanisms in C. australasica , a comprehensive analysis of transcriptomic and proteomic data of leaves from Ca SH, Ca SI, Cs SH, and Cs SI was conducted. Differentially expressed genes (DEGs) between Ca SI and Ca SH were enriched in acridone alkaloid biosynthesis. In contrast, some DEGs between Cs SI and Cs SH were enriched in plant hormone signal transduction, and MAPK signaling pathway. Several differentially expressed proteins (DEPs) between Ca SI and Ca SH were enriched in phenylpropanoid biosynthesis, whereas several DEPs between Cs SI and Cs SH were enriched in amino acids biosynthesis. In response to C Las infection, several genes involved in amino acid metabolism pathway and citrate cycle pathway showed opposite trends in C. australasica and C. sinensis . Among these genes with opposite expression trends, it is noteworthy that in response to HLB, arogenate/prephenate dehydratase and phenylalanine-4-hydroxylase in phenylalanine and tyrosine biosynthesis remained stable in C. australasica. In addition, glutamate dehydrogenase and amino acid N-acetyltransferase, which are involved in arginine metabolism, were up-regulated in C Las-infected C. australasica . The expression levels of isocitrate dehydrogenase, malate dehydrogenase, and aconitate hydratase, which are involved in the citrate cycle, were higher in Ca SI than in Cs SI. Conclusions These data suggest that the stabilization of phenylalanine biosynthesis and the up-regulation of arginine biosynthesis contribute to HLB-tolerance of C. australasica , and that the changes in enzymes in the citrate cycle pathway and flow of carbon sources to arginine biosynthesis reduce the energy supply for HLB pathogens. These results provide new insights into the mechanism of HLB-tolerance in C. australasica , and provide a theoretical molecular basis for breeding HLB-tolerant citrus varieties.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Acetyltransferase / Aconitate hydratase / Agricultural research / Agriculture / Amino acids / Analysis / Arginine / Bacterial diseases of plants / Biomedical and Life Sciences / Biosynthesis / Candidatus Liberibacter asiaticus / Carbon sources / Cellular signal transduction / Citric acid / Citrus / Citrus australasica / Citrus fruits / Citrus greening / Citrus reticulate blanco ‘Shatangju’ / Cloning / Dehydration / Dehydrogenase / Development and progression / Diseases and pests / Enrichment / Flowers & plants / Gene expression / Genes / Genetic aspects / Glutamate dehydrogenase / Health aspects / High-throughput sequencing / Huanglongbing / Hydroxylases / Infections / Isocitrate dehydrogenase / Leaves / Life Sciences / Malate dehydrogenase / MAP kinase / Metabolism / Metabolites / Methods / N-Acetyltransferase / Pathogenesis / Pathogens / Phenylalanine / Phenylalanine 4-monooxygenase / Physiological aspects / Plant bacterial diseases / Plant hormones / Plant immunology / Plant Sciences / Polyamines / Prephenate dehydratase / Proteins / Proteomics / RNA sequencing / Signal transduction / Transcriptomics / Tree Biology / Trends / Tyrosine