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Reid, L.

Publications and source records attributed to Reid, L..

2 recordsLinked to original sources
bioRxiv2019

Host defense responses of CO441 and CL30 maize lines to Fusarium graminearum analyzed by comparative label-free quantitative proteomics

Gibberella ear rot is a disease of maize associated with low yields and the production of harmful mycotoxins therein. The disease is caused by the infection of host Zea mays with fungal pathogen Fusarium graminearum. Resistant (CO441) and susceptible (CL30) inbred maize line kernels were inoculated with conidial suspensions of F. graminearum or water (controls). Ears of maize (cobs) from each line were harvested upon maturation and proteins were extracted from the embryo tissue of the kernels to study tissue-specific response of the host. Embryo proteins from both CO441 and CL30 lines were sequenced using mass spectrometry (LC-MS/MS) and quantified using Label Free Quantification (LFQ). Following filtering, 509 proteins were identified. These proteins were grouped into nine functional categories: Fusarium-derived, late embryogenesis abundant, oil-body, metabolism, stress, cellular, protein storage, metabolism, and defense. Defense proteins were up-regulated in response to infection in both CO441 and CL30 lines. Furthermore, F. graminearum derived proteins were only found in CL30 infected kernels suggesting that resistance may be attributed in part to the inability of Fusarium to establish itself in the embryo. To our knowledge this is the first successful application of LFQ mass spectrometry to the study of host-pathogen response to F. graminearum.\n\nBiological significanceFungal pathogen Fusarium graminearum is responsible for billion dollar losses in crops and contamination of global grains with harmful mycotoxins. By studying host-pathogen interactions of Fusarium and maize on a proteomic level with resistant and susceptible genotypes, the biological interactions occurring during infection of the maturing seed were characterized. Mature kernels of the F. graminearum susceptible maize line CL30 and resistant CO441 line were dissected to permit a proteomic survey of the new sporophytic generation, the embryo. Detailed knowledge of this Host-pathogen interactome will assist development of new cereal lines resistant to the rot diseases caused by Fusarium graminearum.\n\nHighlightsSusceptible (CL30) and Resistant (CO441) lines were injected with water mock or F. graminearum LC-MS/MS of maize embryo protein extracts followed by Label Free Quantification (LFQ) permitted identification, quantification and comparison of proteomes between maize genotypes and treatments Fusarium-derived proteins were abundant only in the susceptible infected embryo Defense proteomes were up-regulated in both lines following infection nsLTP and Protease Inhibitor were significantly over-expressed in the Susceptible line after infection; chitinase and WIP1 were significantly over-expressed in the Resistant line after infection

plant biology↗
bioRxiv2019

Early-Stage Ocular Hypertension Alters Retinal Ganglion Cell Synaptic Transmission in the Visual Thalamus

Axonopathy is a hallmark of many neurodegenerative diseases including glaucoma, where elevated intraocular pressure (ocular hypertension, OHT) stresses retinal ganglion cell (RGC) axons as they exit the eye and form the optic nerve. OHT causes early changes in the optic nerve such as axon atrophy, transport inhibition, and gliosis. Importantly, many of these changes appear to occur prior to irreversible neuronal loss, making them promising points for early diagnosis of glaucoma. It is unknown whether OHT has similarly early effects on the function of RGC output to the brain. To test this possibility, we elevated eye pressure in mice by anterior chamber injection of polystyrene microbeads. 5 weeks post-injection, bead-injected eyes showed a modest RGC loss in the peripheral retina, as evidenced by RBPMS antibody staining. Additionally, we observed reduced dendritic complexity and lower spontaneous spike rate of On-RGCs, targeted for patch clamp recording and dye filling using a Opn4-cre reporter mouse line. To determine the influence of OHT on retinal projections to the brain, we expressed Channelrhodopsin-2 (ChR2) in melanopsin-expressing retinal ganglion cells by crossing the Opn4-cre mouse line with a ChR2-reporter mouse line and recorded post-synaptic responses in thalamocortical relay neurons in the dorsal lateral geniculate nucleus (dLGN) of the thalamus evoked by stimulation with 460 nm light. The use of a Opn4-cre reporter system allowed for expression of ChR2 in a narrow subset of RGCs responsible for image-forming vision in mice. Five weeks following OHT induction, paired pulse and high-frequency stimulus train experiments revealed that presynaptic vesicle release probability at retinogeniculate synapses was elevated. Additionally, miniature synaptic current frequency was slightly reduced in brain slices from OHT mice and proximal dendrites of post-synaptic dLGN relay neurons, assessed using a Sholl analysis, showed a reduced complexity. Strikingly, these changes occurred prior to major loss of RGCs labeled with the Opn4-Cre mouse, as indicated by immunofluorescence staining of ChR2-expressing retinal neurons. Thus, OHT leads to pre- and post-synaptic functional and structural changes at retinogeniculate synapses. Along with RGC dendritic remodeling and optic nerve transport changes, these retinogeniculate synaptic changes are among the earliest signs of glaucoma.

neuroscience↗