No abstract

Low-molecular-weight sugars serve as protectants for cellular membranes and macromolecules under the condition of dehydration caused by environmental stress such as desiccation and freezing. These sugars also affect plant growth and development by provoking internal signaling pathways. We previously showed that both sugars and the stress hormone abscisic acid (ABA) enhance desiccation tolerance of gemma, a dormant propagule of the liverwort Marchantia polymorpha. To determine the role of ABA in sugar responses in liverworts, we generated genome-editing lines of M. polymorpha ABA DEFICIENT 1 (MpABA1) encoding zeaxanthin epoxidase, which catalyzes the initial reaction toward ABA biosynthesis. The generated Mpaba1 lines that accumulated only a trace amount of endogenous ABA showed reduced desiccation tolerance and reduced sugar responses. RNA-seq analysis of sucrose-treated gemmalings of M. polymorpha revealed that expression of a large part of sucrose-induced genes was reduced in Mpaba1 compared to the wild-type. Furthermore, Mpaba1 accumulated smaller amounts of low-molecular-weight sugars in tissues upon sucrose treatment than the wild-type, with reduced expression of genes for sucrose synthesis, sugar transporters, and starch-catabolizing enzymes. These results indicate that endogenous ABA plays a role in the regulation of the positive feedback loop for sugar-induced sugar accumulation in liverworts, enabling the tissue to have desiccation tolerance. 1 | INTRODUCTION Low molecular-weight sugars such as sucrose are fundamental compounds serving as energy and carbon sources to support plant growth Nobiza Khatun and Akihisa Shinozawa equally contributed to this study and share first authorship.

Background The number of people with dementia increases in an aging society; therefore, promoting policies for dementia throughout the community is crucial to creating a dementia-friendly society. Understanding the status of older adults with dementia in each region of Japan will be a helpful indicator. We calculated Dementia-free Life Expectancy and aimed to examine regional disparities and their associated factors. Methods We calculated Dementia-free Life Expectancy and Life Expectancy with Dementia for each secondary medical area in Japan based on the Degree of Independence in Daily Living for the Demented Elderly, using data extracted from the Japanese long-term care insurance claims database. We then conducted a partial least squares regression analysis, the objective variables being Dementia-free Life Expectancy and Life Expectancy with Dementia for both sexes at age 65, and explanatory regional-level variables included demographic, socioeconomic, and healthcare resources variables. Results The mean estimated regional-level Dementia-free Life Expectancy at age 65 was 17.33 years (95% confidence interval [CI] 17.27–17.38) for males and 20.05 years (95% CI 19.99–20.11) for females. Three latent components identified by partial least squares regression analysis represented urbanicity, socioeconomic conditions, and health services-related factors of the secondary medical areas. The second component explained the most variation in Dementia-free Life Expectancy of the three, indicating that higher socioeconomic status was associated with longer Dementia-free Life Expectancy. Conclusions There were regional disparities in secondary medical area level Dementia-free Life Expectancy. Our results suggest that socioeconomic conditions are more related to Dementia-free Life Expectancy than urbanicity and health services-related factors.

SummaryDormancy is a key process for land plants to adapt drastically changing terrestrial environment. The liverwort Marchantia polymorpha produce dormant propagules called gemmae for asexual reproduction. The plant hormone abscisic acid (ABA) plays significant roles in the regulation of dormancy in both seed of flowering plants and gemma of M. polymorpha.Based on the previous transcriptome analysis, here we identified the basic helix-loop-helix transcription factor MpHYPNOS (MpHYP), as a key regulator of gemma dormancy.The knock-out mutants showed much higher germination rate of gemmae in gemma cup than ABA-related mutants did, while the growth and development were the same as wild type. Transient induction of MpHYP caused irreversible growth arrest in gemma and thallus. Transcriptome and qRT-PCR analyses revealed that MpHYP repressed cell-cycle related genes and induced the ABA biosynthesis and responsive genes. Indeed, ABA amounts were increased or decreased by overexpression or knock-out of MpHYP, respectively. However, the growth arrest caused by MpHYP overexpression was not suppressed by the mutation in the ABA receptor gene.These data suggest that MpHYP regulates gemma dormancy and thallus growth partially through the ABA pathway. Our findings would provide the clues to understand ABA-dependent and independent regulation of dormancy in land plants.

Background The number of people with dementia increases in an aging society; therefore, promoting policies for dementia throughout the community is crucial to creating a dementia-friendly society. Understanding the status of older adults with dementia in each region of Japan will be a helpful indicator. We calculated Dementia-free Life Expectancy and aimed to examine regional disparities and their associated factors. Methods We calculated Dementia-free Life Expectancy and Life Expectancy with Dementia for each secondary medical area in Japan based on the Degree of Independence in Daily Living for the Demented Elderly, using data extracted from the Japanese long-term care insurance claims database. We then conducted a partial least squares regression analysis, the objective variables being Dementia-free Life Expectancy and Life Expectancy with Dementia for both sexes at age 65, and explanatory regional-level variables included demographic, socioeconomic, and healthcare resources variables. Results The mean estimated regional-level Dementia-free Life Expectancy at age 65 was 17.33 years (95% confidence interval [CI] 17.27–17.38) for males and 20.05 years (95% CI 19.99–20.11) for females. Three latent components identified by partial least squares regression analysis represented urbanicity, socioeconomic conditions, and health services-related factors of the secondary medical areas. The second component explained the most variation in Dementia-free Life Expectancy of the three, indicating that higher socioeconomic status was associated with longer Dementia-free Life Expectancy. Conclusions There were regional disparities in secondary medical area level Dementia-free Life Expectancy. Our results suggest that socioeconomic conditions are more related to Dementia-free Life Expectancy than urbanicity and health services-related factors.