Editing of the starch branching enzyme gene SBE2 generates high-amylose storage roots in cassava.

KEY MESSAGE: The production of high-amylose cassava through CRISPR/Cas9-mediated mutagenesis of the starch branching enzyme gene SBE2 was firstly achieved. High-amylose cassava (Manihot esculenta Crantz) is desirable for starch industrial applications and production of healthier processed food for human consumption. In this study, we report the production of high-amylose cassava through CRISPR/Cas9-mediated mutagenesis of the starch branching enzyme 2 (SBE2). Mutations in two targeted exons of SBE2 were identified in all regenerated plants; these mutations, which included nucleotide insertions, and short or long deletions in the SBE2 gene, were classified into eight mutant lines. Three mutants, M6, M7 and M8, with long fragment deletions in the second exon of SBE2 showed no accumulation of SBE2 protein. After harvest from the field, significantly higher amylose (up to 56% in apparent amylose content) and resistant starch (up to 35%) was observed in these mutants compared with the wild type, leading to darker blue coloration of starch granules after quick iodine staining and altered starch viscosity with a higher pasting temperature and peak time. Further 1H-NMR analysis revealed a significant reduction in the degree of starch branching, together with fewer short chains (degree of polymerization [DP] 15-25) and more long chains (DP>25 and especially DP>40) of amylopectin, which indicates that cassava SBE2 catalyzes short chain formation during amylopectin biosynthesis. Transition from A- to B-type crystallinity was also detected in the starches. Our study showed that CRISPR/Cas9-mediated mutagenesis of starch biosynthetic genes in cassava is an effective approach for generating novel varieties with valuable starch properties for food and industrial applications.

Exploring Sleep Quality and Related Factors in Chinese Midlife Women.

We investigated the percentage of women with poor sleep quality and its related factors among mainland Chinese women. Sleep quality and menopausal status were self-reported. We explored the contribution of possible risk factors, including sociodemographic characteristics, comorbidities, lifestyle, psychological status, stressful life events, and vasomotor symptoms. We found that 38.6% of midlife Chinese women were poor sleepers. This percentage was higher in comparison with women from other Asian countries. Our multiple logistic regression showed that anxiety, comorbidities, perceived stress, and vasomotor symptoms were risk factors for poor sleep quality.

Vitamin D levels and other factors related to bone mineral density during pregnancy.

BACKGROUND: Multiple factors appear to affect bone mineral density (BMD) during pregnancy. AIMS: The aim of this study was to determine the relationships between BMD of the os calcaneus as measured by quantitative ultrasound (QUS) and levels of vitamin D3, parathyroid hormone (PTH), albumin (Alb), calcium (Ca), phosphorus (P) and alkaline phosphatase (ALP) in a group of Chinese women. METHODS: Multiple parameters, including density of the os calcaneus, were recorded for a group of 130 women in early (mean gestation, 16.09 ± 2.65 weeks) and late (mean gestation, 32.01 ± 3.45 weeks) stages of pregnancy; 139 nonpregnant women served as controls. RESULTS: Bone mineral density was lower in pregnant women than in controls at both early and late stages of pregnancy. Levels of Ca, P and ALP were significantly negatively correlated with BMD over the course of pregnancy. Levels of D3, PTH and Alb showed a falling trend from early to late pregnancy as with QUS BMD of the os calcaneus, but the correlations were not statistically significant. CONCLUSIONS: Many factors are correlated with BMD. We suggest that levels of Ca and ALP should be included in the routine examination of pregnant women.