AtMYB61, an R2R3-MYB transcription factor, functions as a pleiotropic regulator via a small gene network.

Throughout their lifetimes, plants must coordinate the regulation of various facets of growth and development. Previous evidence has suggested that the Arabidopsis thaliana R2R3-MYB, AtMYB61, might function as a coordinate regulator of multiple aspects of plant resource allocation. Using a combination of cell biology, transcriptome analysis and biochemistry, in conjunction with gain-of-function and loss-of-function genetics, the role of AtMYB61 in conditioning resource allocation throughout the plant life cycle was explored. In keeping with its role as a regulator of resource allocation, AtMYB61 is expressed in sink tissues, notably xylem, roots and developing seeds. Loss of AtMYB61 function decreases xylem formation, induces qualitative changes in xylem cell structure and decreases lateral root formation; in contrast, gain of AtMYB61 function has the opposite effect on these traits. AtMYB61 coordinates a small network of downstream target genes, which contain a motif in their upstream regulatory regions that is bound by AtMYB61, and AtMYB61 activates transcription from this same motif. Loss-of-function analysis supports the hypothesis that AtMYB61 targets play roles in shaping subsets of AtMYB61-related phenotypes. Taken together, these findings suggest that AtMYB61 links the transcriptional control of multiple aspects of plant resource allocation.

A novel approach to long-term respiratory care: results of a community-based post-rehabilitation maintenance program in COPD.

BACKGROUND: Although the short-term benefits of pulmonary rehabilitation (PR) are well established, improvements in exercise tolerance and health status diminish over time. The objectives of this study were to determine the feasibility and within-subject effects of a 1-year community-based maintenance exercise program for patients with COPD following completion of hospital-based PR. METHODS: A single-arm longitudinal study was undertaken. After completion of PR, consecutive patients with COPD were recruited to attend a twice weekly exercise program supervised by fitness consultants at a local community centre. The transition from hospital to the community was facilitated by a case manager. Outcome measurements at baseline (pre-PR), post-PR, 6-months and 1-year included the 6-minute walk test (6MWT) for exercise capacity and the Chronic Respiratory Questionnaire (CRQ) for health-related quality of life. Feasibility was assessed primarily through subject adherence. RESULTS: A total of 29 patients (mean age 66.8 ± 7.8 years, mean FEV1 45.1 ± 18.8 percent predicted) were enrolled in the program. Mean compliance to twice weekly exercise was 70%. No adverse events were reported. Statistically significant and clinically important improvements in the 6MWT and CRQ total and dyspnea domain were observed at 6-months and 1-year after PR compared to baseline (all p < 0.01). CONCLUSIONS: A community-based maintenance exercise program is feasible and can successfully preserve exercise capacity and health-related quality of life following institutionally-based PR in patients with moderate to severe COPD. A more formal evaluation of this approach is warranted.

A randomized controlled trial of balance training during pulmonary rehabilitation for individuals with COPD.

BACKGROUND: Deficits in balance are increasingly recognized among the important secondary impairments in COPD. The purpose of this study was to investigate the effect of a balance-training program on measures of balance and physical function in patients with COPD enrolled in pulmonary rehabilitation (PR). METHODS: Patients were assigned randomly to an intervention or control group. The intervention group underwent balance training three times a week for 6 weeks concurrently with PR. The control group received only the 6-week PR program. Clinical balance measures included the Berg Balance Scale (BBS), the Balance Evaluation Systems Test (BESTest), and the Activities-Specific Balance Confidence (ABC) scale. The physical function subscale of the 36-Item Short Form Health Survey (PF-10) and the 30-s chair-stand test were used to measure self-reported physical function and lower-extremity muscle strength, respectively. RESULTS: Thirty-nine patients with COPD (mean FEV1, 37.5% ± 15.6% predicted) were enrolled in the study. Mean compliance with the balance-training program was 82.5%, and no adverse events were reported. Compared with control subjects, scores on the BBS (P < .01), BESTest (P < .01), PF-10 (P = .01), and 30-s chair-stand (P = .02) were significantly improved in the intervention group. No significant between-group differences were found in change scores on the ABC scale (P = .2). CONCLUSIONS: Our results support the feasibility and effectiveness of balance training as part of PR for improving balance performance, muscle strength, and self-reported physical function in patients with moderate to severe COPD.