Ghanim, Murad


Publications (7)

Effects of calcium-regulated autophagy on <i>Candidatus</i> Liberibacter solanacearum in carrot psyllid midguts

Citation
Sarkar et al. [posted content, 2022]
Names
“Liberibacter solanacearum”
Abstract
AbstractCandidatus Liberibacter solanacearum (CLso) transmitted by the carrot psyllid, Bactericera trigonica causes carrot yellows in Israel, and has recently gained much importance due to the excessive economical loss. Understanding the interactions between CLso and the psyllid at the cellular level is fundamental for the disease management. Here, we demonstrate the role of calcium ATPase, cytosolic calcium and most importantly Beclin1 in regulating autophagy and its association with Liberibacter. Presence of CLso generates reactive oxygen species and induces the expression of the detoxification enzymes in the psyllid midguts. CLso also induces the expression of both sarco/endoplasmic reticulum Ca2+ pump (SERCA) and 1,4,5-trisphosphate receptors (ITPR) in the midguts, followed by high levels of calcium in the cytosol. Silencing these proteins individually disrupted the calcium levels in the cytosol leading to direct effects on autophagy and thus on Liberibacter. On the other hand, inhibiting Beclin1-phosphorylation through different calcium induced kinases altered the expression of autophagy and CLso abundance. This study establishes a direct correlation between cytosolic calcium levels, autophagy and CLso in the carrot psyllid midgut.

The Actin Cytoskeleton Mediates Transmission of “ Candidatus Liberibacter solanacearum” by the Carrot Psyllid

Citation
Sarkar et al. (2021). Applied and Environmental Microbiology 87 (3)
Names
“Liberibacter solanacearum”
Subjects
Applied Microbiology and Biotechnology Biotechnology Ecology Food Science
Abstract
Plant diseases caused by vector-borne pathogens are responsible for tremendous losses and threaten some of the most important agricultural crops. A good example is the citrus greening disease, which is caused by bacteria of the genus Liberibacter and is transmitted by psyllids; it has devastated the citrus industry in the United States, China, and Brazil.

A Transcriptomics Approach Reveals Putative Interaction of Candidatus Liberibacter Solanacearum with the Endoplasmic Reticulum of Its Psyllid Vector

Citation
Ghosh et al. (2019). Insects 10 (9)
Names
Liberibacter “Liberibacter solanacearum” Ca. Liberibacter asiaticus
Subjects
Insect Science
Abstract
Candidatus Liberibacter solanacerum (CLso), transmitted by Bactericera trigonica in a persistent and propagative mode causes carrot yellows disease, inflicting hefty economic losses. Understanding the process of transmission of CLso by psyllids is fundamental to devise sustainable management strategies. Persistent transmission involves critical steps of adhesion, cell invasion, and replication before passage through the midgut barrier. This study uses a transcriptomic approach for the identification of differentially expressed genes with CLso infection in the midguts, adults, and nymphs of B. trigonica and their putative involvement in CLso transmission. Several genes related to focal adhesion and cellular invasion were upregulated after CLso infection. Interestingly, genes involved with proper functionality of the endoplasmic reticulum (ER) were upregulated in CLso infected samples. Notably, genes from the endoplasmic reticulum associated degradation (ERAD) and the unfolded protein response (UPR) pathway were overexpressed after CLso infection. Marker genes of the ERAD and UPR pathways were also upregulated in Diaphorina citri when infected with Candidatus Liberibacter asiaticus (CLas). Upregulation of the ERAD and UPR pathways indicate induction of ER stress by CLso/CLas in their psyllid vector. The role of ER in bacteria–host interactions is well-documented; however, the ER role following pathogenesis of CLso/CLas is unknown and requires further functional validation.

Comparison of the Genome Sequences of “Candidatus Portiera aleyrodidarum” Primary Endosymbionts of the Whitefly Bemisia tabaci B and Q Biotypes

Citation
Jiang et al. (2013). Applied and Environmental Microbiology 79 (5)
Names
Ca. Portiera aleyrodidarum
Subjects
Applied Microbiology and Biotechnology Biotechnology Ecology Food Science
Abstract
ABSTRACT“CandidatusPortiera aleyrodidarum” is the primary endosymbiont of whiteflies. We report two complete genome sequences of this bacterium from the worldwide invasive B and Q biotypes of the whiteflyBemisia tabaci. Differences in the two genome sequences may add insights into the complex differences in the biology of both biotypes.

Genome Sequences of the Primary Endosymbiont “Candidatus Portiera aleyrodidarum” in the Whitefly Bemisia tabaci B and Q Biotypes

Citation
Jiang et al. (2012). Journal of Bacteriology 194 (23)
Names
Ca. Portiera aleyrodidarum
Subjects
Microbiology Molecular Biology
Abstract
ABSTRACT “ Candidatus Portiera aleyrodidarum” is the obligate primary endosymbiotic bacterium of whiteflies, including the sweet potato whitefly Bemisia tabaci , and provides essential nutrients to its host. Here we report two complete genome sequences of this bacterium from the B and Q biotypes of B. tabaci .