Defective mitochondrial function by mutation in THICK ALEURONE 1 encoding a mitochondrion-targeted single-stranded DNA-binding protein leads to increased aleurone cell layers and improved nutrition in rice

Cereal endosperm comprises an outer aleurone and an inner starchy endosperm.Although these two tissues have the same developmental origin,they differ in morphology,cell fate,and storage product accumulation,with the mechanism largely unknown.Here,we report the identification and characterization of rice thick aleurone 1(ta1)mutant that shows an increased number of aleurone cell layers and increased contents of nutritional factors including proteins,lipids,vitamins,dietary fibers,and micronutrients.We identified that the TA1 gene,which is expressed in embryo,aleurone,and subaleurone in caryopses,encodes a mitochondrion-targeted protein with single-stranded DNA-binding activity named OsmtSSB1.Cytological analyses revealed that the increased aleurone cell layers in ta1 originate from a developmental switch of subaleurone toward aleurone instead of starchy endosperm in the wild type.We found that TA1/OsmtSSB1 interacts with mitochondrial DNA recombinase RECA3 and DNA helicase TWINKLE,and downregulation of REC A3 or TWINKLE also leads to ta1-like phenotypes.We further showed that mutation in TA1/OsmtSSB1 causes elevated illegitimate recombinations in the mitochondrial genome,altered mitochondrial morphology,and compromised energy supply,suggesting that the OsmtSSB1-mediated mitochondrial function plays a critical role in subaleur one cell-fate determination in rice.

Amino acid-based enteral nutrition is effective for pediatric Crohn’s disease:a multicenter prospective study

Background:Exclusive enteral nutrition(EEN)therapy effectively induces remission in pediatric Crohn’s disease(CD).However,this may depend on the type of enteral formula used.Moreover,data on the efficacy of amino acid-based EEN are limited.Thus,we aimed to prospectively evaluate the efficacy of amino acid-based formulas for EEN in pediatric patients with active CD.Methods:Patients with active CD aged between 6 and 17years were recruited into this prospective study from four hospitals in China between March 2019 and December 2021.Patients received EEN for 8weeks.Inflammatory and nutrition-associated indices were evaluated at 0,4,and 8weeks after treatment.Paired t-tests and Wilcoxon signed-rank tests were used to compare continuous and categorical variables before and after intervention,respectively.Results:Twenty-four patients were included in the analysis.After an 8-week intervention period,the CD activity index significantly decreased(26.3±12.2 vs 7.1±8.3,P<0.001).Most patients(66.7%)achieved complete clinical remission.Among the 22 patients who had ulcers and erosions diagnosed endoscopically at baseline,10(45.5%)achieved complete mucosal healing.The degree of thickening of the intestinal wall was significantly reduced after EEN intervention,with a transmural healing rate of 42.9%.Furthermore,the serum inflammatory markers decreased and there was a significant improvement in the nutrition-related indices(P<0.05).There were no severe adverse effects.Conclusions:Amino acid-based EEN is effective and safe for treating pediatric-onset CD.Studies with larger sample sizes and mechanistic and follow-up studies are required to further validate these findings.

Xu Tian, Xiaohua YuThe Demand for Nutrients in China

China is experiencing a nutritional transition accompanied by its rapid economic growth. However, the relationship between income growth and nutritional improvement is still unclear. In contrast with the biased indirect method, this paper employs a direct method to estimate the income elasticities of 22 nutrients using household survey data to fill the gap in the current literature. Our results indicate that the income elasticities of most nutrients are smaller than that which is stated in the current literature using the indirect method, and vary for different income groups.