Lasting consequences of psyllid (Bactericera cockerelli L.) infestation on tomato defense, gene expression, and growth

Abstract

Background The tomato psyllid, Bactericera cockerelli Šulc (Hemiptera: Triozidae), is a pest of solanaceous crops such as tomato (Solanum lycopersicum L.) in the U.S. and vectors the disease-causing pathogen ‘Candidatus Liberibacter solanacearum’. Currently, the only effective strategies for controlling the diseases associated with this pathogen involve regular pesticide applications to manage psyllid population density. However, such practices are unsustainable and will eventually lead to widespread pesticide resistance in psyllids. Therefore, new control strategies must be developed to increase host-plant resistance to insect vectors. For example, expression of constitutive and inducible plant defenses can be improved through selection. Currently, it is still unknown whether psyllid infestation has any lasting consequences on tomato plant defense or tomato plant gene expression in general. Results In order to characterize the genes putatively involved in tomato defense against psyllid infestation, RNA was extracted from psyllid-infested and uninfested tomato leaves (Moneymaker) 3 weeks post-infestation. Transcriptome analysis identified 362 differentially expressed genes. These differentially expressed genes were primarily associated with defense responses to abiotic/biotic stress, transcription/translation, cellular signaling/transport, and photosynthesis. These gene expression changes suggested that tomato plants underwent a reduction in plant growth/health in exchange for improved defense against stress that was observable 3 weeks after psyllid infestation. Consistent with these observations, tomato plant growth experiments determined that the plants were shorter 3 weeks after psyllid infestation. Furthermore, psyllid nymphs had lower survival rates on tomato plants that had been previously psyllid infested. Conclusion These results suggested that psyllid infestation has lasting consequences for tomato gene expression, defense, and growth.

Effects of ‘Candidatus Liberibacter solanacearum’ haplotypes A and B on tomato gene expression and geotropism

“…This hypothesis is supported by the tomato plant geotropism experiments which showed that Lso-infected plants are likely unresponsive to auxin signaling, which is an outcome predicted by the transcriptomic results which suggested auxin-responsive genes are suppressed in Lso-infected tomatoes. The results of the current research parallel the transcriptomic analysis characterizing the genes differentially expressed in response to psyllid infestation [ 19 , 22 ], which also demonstrated long-term consequences for plant expression following biotic challenge. Interestingly, some of the significant differences between uninfected and infected plants were the general promotion of jasmonic acid-related pathways and cell wall modification (Supplementary Tables 5 and 6 ), and these same processes were affected even more in LsoB-infected plants (Supplementary Tables 12 and 13 ).…”

“…The MDS distance plot also demonstrated weak separations between control and Lso-free psyllid-infested plants as well as a separation between LsoA- and LsoB-infected plants. These results suggested that overall gene expression was most different between uninfected and infected plants but also suggested that psyllid infestation and Lso haplotype have significant consequences for tomato plant gene expression [ 22 ]. This interpretation is supported by the binomial distribution of differential expression (DE) values among all sample libraries (Supplementary Fig.…”

Modifying Anthocyanins Biosynthesis in Tomato Hairy Roots: A Test Bed for Plant Resistance to Ionizing Radiation and Antioxidant Properties in Space

“…In tomatoes, SlCM2 has been also shown to be upregulated under drought stress ( Filiz et al, 2019 ). Among downregulated genes, Solyc08g008630.3.1 (Log 2 Fc = −3.34; tomato chloroplastic beta-carotene isomerase D27 Dwarf27 ) is involved in strigolactone and beta-carotene biosynthesis and has been found to be downregulated in psyllid-infested tomato plants ( Harrison et al, 2021 ). Solyc04g050930.3.1 (Log 2 Fc = −2.07; tomato violaxanthin de-epoxidase VDE ) is involved in the carotenoid biosynthesis.…”

Identification of the Complex Interplay Between Nematode-Related lncRNAs and Their Target Genes in Glycine max L.

“…Similar to SCN data set, In RAD, the novel associations among DE-lncRNAs and the major nematode-responsive DEGs were elegantly recognized. NTF2 as overexpressed regulators in infected resistant soybean roots (de Sá et al, 2012), RING/ FYVE/PHD zinc finger superfamily protein as positive regulator of downstream targets under nematode infection to establish resistance at transcriptional level (Song et al, 2019), GSH introduced in the modulation of giant cell metabolism and manipulation of ROS pathway (Baldacci-Cresp et al, 2012;Wu, 2019), glycosyl hydrolases family with a cell wall-modifying role (Nyaku et al, 2013), Aquaporin-like superfamily gene as a membrane transport protein-coding gene and nematodeinduced gene (Hammes et al, 2005), signal peptide peptidase-like2 as a defense response inducer (Harrison et al, 2021), and CAP superfamily gene as highly induced protective gene (Hamamouch et al, 2011) were some nematode responseassociated DEGs identified modules of RAD which showed interaction with DE-lncRNAs.…”