Steroidal glycoalkaloids contribute to anthracnose resistance in Solanum lycopersicum.

Anthracnose is a widespread plant disease caused by various species of the fungal pathogen Colletotrichum. In solanaceous plants such as tomato (Solanum lycopersicum), Colletotrichum infections exhibit a quiescent, asymptomatic state in developing fruit, followed by a transition to necrotrophic infections in ripe fruit. Through analysis of fruit tissue extracts of 95L368, a tomato breeding line that yields fruit with enhanced anthracnose resistance, we identified a role for steroidal glycoalkaloids (SGAs) in anthracnose resistance. The SGA α-tomatine and several of its derivatives accumulated at higher levels, in comparison with fruit of the susceptible tomato cultivar US28, and 95L368 fruit extracts displayed fungistatic activity against Colletotrichum. Correspondingly, ripe and unripe 95L368 fruit displayed enhanced expression of glycoalkaloid metabolic enzyme (GAME) genes, which encode key enzymes in SGA biosynthesis. Metabolomics analysis incorporating recombinant inbred lines generated from 95L368 and US28 yielded strong positive correlations between anthracnose resistance and accumulation of α-tomatine and several derivatives. Lastly, transient silencing of expression of the GAME genes GAME31 and GAME5 in anthracnose-susceptible tomato fruit yielded enhancements to anthracnose resistance. Together, our data support a role for SGAs in anthracnose defense in tomato, with a distinct SGA metabolomic profile conferring resistance to virulent Colletotrichum infections in ripe fruit.

Rapid component of excess post-exercise oxygen consumption of children of different weight status after playing active video games.

BACKGROUND: Excess post-exercise oxygen consumption (EPOC) of children could indicate the potential of an exercise therapy to treat or prevent obesity. However, EPOC as a result of playing active video games (AVG) has been poorly investigated. Therefore, we aimed to investigate the rapid component of EPOC of children with healthy weight and overweight/obesity (according to their BMI percentile) after playing AVGs that feature predominately upper body (UB) and whole-body (WB) movement. METHODS: Twenty-one children with healthy weight (BMI percentile < 85%) and with overweight/obesity (BMI percentile ≥ 85%) randomly underwent two 10-min AVG sessions (UB and WB). The heart rate (HR), minute ventilation (VE), oxygen consumption (VO2) and carbon dioxide production (VCO2) were recorded during exercise and post-exercise recovery period. For the rapid component of EPOC in each AVG session, measurements were recorded every 15 s for 5-min of post-exercise recovery. The rate of perceived exertion (RPE) was also measured immediately before and after each AVG play. RESULTS: Children with overweight/obesity had a higher average of absolute VE, VO2, and VCO2 than their healthy-weight counterparts (BMI percentile < 85%; n = 21) during post-exercise recovery. RPE, HR, and HR% were not different between the game sessions and weight groups. Children with overweight/obesity showed a higher absolute VO2 during EPOC than healthy-weight children in both game sessions, but relative VO2 was higher in healthy-weight children during EPOC. No differences were observed for EPOC between UB and WB sessions. CONCLUSIONS: Children with overweight/obesity had a greater EPOC than healthy-weight children after AVG sessions in terms of absolute oxygen values, whereas healthy-weight children have higher EPOC considering relative VO2 when controlling for body mass. UB and WB AVGs induced a similar EPOC among children with healthy weight and overweight/obesity. As UB and WB AVGs induce the rapid component of EPOC in children regardless their weight status, AVGs could be used as an exercise method to treat and prevent child obesity.