Biology subjects

Grant, S. C.

Publications and source records attributed to Grant, S. C..

3 recordsLinked to original sources

bioRxiv2026

Morphological and biochemical evaluation of tolerance to water deficit identifies SlCLE9 as a novel regulator of drought stress

We performed a screening to evaluate the responses to water deficit before the flowering stage in a panel of 31 genotypes composed of one commercial hybrid, one wild species, multiple ex-PVP (vintage) lines, several commercial heirlooms from the Northeast USA, Mexican landraces from hot and humid environments and genome edited lines with altered flowering and inflorescence traits. We characterized 18 different morphological, physiological and biochemical traits to assess the response to 40% water deficit. We observed diverse morphological, physiological and biochemical responses across the 31 genotypes screened, suggesting the presence of useful variation for breeding for drought tolerance in cultivated tomato. Interestingly, some heirlooms exhibited superior performance under drought, suggesting they can be used as donors to discover novel genes involved in drought responses. Unexpectedly, we found mutants in SlCLE9, a paralog of the stem cell regulator SlCLV3 known to co-regulate meristem proliferation in tomato, exhibited enhanced drought tolerance. Notably, the slcle9 mutant also conferred drought tolerance when used as rootstock with grafted scions from our reference cultivar M82, suggesting SlCLE9 influence root architecture and drought response. Consistent with this, we found SlCLE9 is transcriptionally upregulated in roots and leaves during drought stress, and exogenous application of SlCLE9 modifies root growth and response to drought. Altogether, our screening uncovered new potential trait donors for breeding against drought stress and describes a novel role for SlCLE9 in drought tolerance.

plant biology↗

bioRxiv2022

Multinuclear MRI reveals early efficacy of stem cell therapy in stroke

Compromised adult human mesenchymal stem cells (hMSC) can impair cell therapy efficacy and further reverse ischemic recovery. However, in vitro assays require extended passage to characterize cells, limiting rapid assessment for therapeutic potency. Multinuclear magnetic resonance imaging and spectroscopy (MRI/S) provides near real-time feedback on disease progression and tissue recovery. Applied to ischemic stroke, 23Na MRI evaluates treatment efficacy within 24 h after middle cerebral artery occlusion, showing recovery of sodium homeostasis and lesion reduction in specimens treated with hMSC while 1H MRS identifies reduction in lactate levels. This combined metric was confirmed by evaluating treatment groups receiving healthy or compromised hMSC versus control (sham saline injection) over 21 d. Behavioral tests to assess functional recovery and cell analysis for immunomodulatory and macrophage activity to detect hMSC potency confirm MR findings. Clinically, these MR metrics may prove critical to early evaluations of therapeutic efficacy and overall stroke recovery.

bioengineering↗

bioRxiv2019

Regulation of cerebrospinal fluid and brain tissue sodium levels by choroid plexus and brain capillary endothelial cell Na+, K+-ATPases during migraine

BackgroundCerebrospinal fluid (CSF) and brain tissue sodium levels increase during migraine. However, little is known regarding the underlying mechanisms of sodium homeostasis disturbance in the brain during the onset and propagation of migraine. Exploring the cause of sodium dysregulation in the brain is important, since correction of the altered sodium homeostasis could potentially treat migraine. Under the hypothesis that disturbances in sodium transport mechanisms at the blood-CSF barrier (BCSFB) and/or the blood-brain barrier (BBB) are the underlying cause of the elevated CSF and brain tissue sodium levels during migraines, we developed a mechanistic, differential equation model of a rats brain to compare the significance of the BCSFB and the BBB in controlling CSF and brain tissue sodium levels. The model includes the ventricular system, subarachnoid space, brain tissue and blood. Sodium transport from blood to CSF across the BCSFB, and from blood to brain tissue across the BBB were modeled by influx permeability coefficients Pcp and Pbc, respectively, while sodium movement from CSF into blood across the BCSFB, and from brain tissue to blood across the BBB were modeled by efflux permeability coefficients [Formula] and [Formula], respectively. We then performed a global sensitivity analysis to investigate the sensitivity of the ventricular CSF, subarachnoid CSF and brain tissue sodium concentrations to pathophysiological variations in [Formula] and [Formula]. Our results show that the ventricular CSF sodium concentration is highly influenced by perturbations of Pcp, and to a much lesser extent by perturbations of [Formula]. Brain tissue and subarachnoid CSF sodium concentrations are more sensitive to pathophysiological variations of Pbc and [Formula] than variations of Pcp and [Formula] within 30 minutes of the onset of the perturbations. However, Pcp is the most sensitive model parameter, followed by Pbc and [Formula], in controlling brain tissue and subarachnoid CSF sodium levels within 2 hours of the perturbation onset.

systems biology↗