Reduced glutathione (GSH) is considered to exert a strong influence on cellular redox homeostasis and to regulate gene expression, but these processes remain poorly characterized. Severe GSH depletion specifically inhibited root meristem development, while low root GSH levels decreased lateral root densities. The redox potential of the nucleus and cytosol of Arabidopsis thaliana roots determined using roGFP probes was between -300 and -320 mV. Growth in the presence of the GSH-synthesis inhibitor buthionine sulfoximine (BSO) increased the nuclear and cytosolic redox potentials to approximately -260 mV. GSH-responsive genes including transcription factors (SPATULA, MYB15, MYB75), proteins involved in cell division, redox regulation (glutaredoxinS17, thioredoxins, ACHT5 and TH8) and auxin signalling (HECATE), were identified in the GSH-deficient root meristemless 1-1 (rml1-1) mutant, and in other GSH-synthesis mutants (rax1-1, cad2-1, pad2-1) as well as in the wild type following the addition of BSO. Inhibition of auxin transport had no effect on organ GSH levels, but exogenous auxin decreased the root GSH pool. We conclude that GSH depletion significantly increases the redox potentials of the nucleus and cytosol, and causes arrest of the cell cycle in roots but not shoots, with accompanying transcript changes linked to altered hormone responses, but not oxidative stress.

BackgroundAsthma is becoming increasingly prevalent among children in China. Poor parent knowledge and attitudes often contribute to inappropriate management practices, leading to deficiencies in the care process. We aimed to document the knowledge, attitudes and practices (KAP) of parents of children with asthma and analyze how knowledge and attitudes relate to practices. Our secondary objective was to identify the factors associated with parent KAP scores.MethodsA KAP questionnaire was distributed to parents caring for 2960 children (0–14 years) diagnosed with asthma for at least 3 months from China’s 29 provinces. A 50-item questionnaire was devised for this cross-sectional survey based on a comprehensive review of the subject. Questionnaires were scored on 30 items regarding parent asthma-related KAP, with one point for every correct response and a possible range of 0–13 for knowledge, 0–7 for attitudes and 0–10 for practices. Higher scores indicated better KAP. Chi-squared tests and logistic regression were used to identify factors associated with practices and combined KAP scores.ResultsThe response rate was 83.95% (2485/2960). Only 18.31% (455/2485) of parents correctly answered ≥ 60% of the knowledge questions (mean = 5.69). Most (89.85%; 2226/2485) gave positive responses to ≥ 60% of the attitude questions (mean = 5.23) while 67.89% (1687/2485) correctly answered ≥ 60% of the practices questions (mean = 6.19). Knowledge and attitudes were positively associated with pulmonary function testing, regular physician visits, monitoring with a peak flow meter and the Children’s Asthma Control Test questionnaire, avoidance of asthma triggers, using an inhaled β2 receptor agonist and adherence to medication regimen (p ≤ 0.05). Attitudes were also associated with allergen testing. In logistic regression analysis, high KAP scores (dichotomized by a cut-off score of 18) were positively associated with food allergy, rhinitis, physician visits, frequency of visits and parent education (p < 0.05, OR > 1).ConclusionsGenerally, the parents’ KAP were poor. A gap between recommended and actual practice was observed, which may be related to inadequate knowledge about and poor attitudes toward childhood asthma. Improving knowledge and attitudes may encourage better practices among parents of children with asthma.

SummaryWe demonstrate that the GPX proteins are important in the control of root architecture and that loss of any of the GPX isoforms exerts an influence on lateral root density.