Genome-Wide Identification and Expression Patterns of the SWEET Gene Family in Bletilla striata and its Responses to Low Temperature and Oxidative Stress.

SWEETs (sugars will eventually be exported transporters), a well-known class of sugar transporters, are involved in plant growth and development, sugar transport, biotic and abiotic stresses, etc. However, to date, there have been few investigations of SWEETs in Orchidaceae. In this study, 23 SWEET genes were identified in Bletilla striata for the first time, with an MtN3/saliva conserved domain, and were divided into four subgroups by phylogenetic tree. The same subfamily members had similar gene structures and motifs. Multiple cis-elements related to sugar and environmental stresses were found in the promoter region. Further, 21 genes were localized on 11 chromosomes and 2 paralogous pairs were found via intraspecific collinearity analysis. Expression profiling results showed that BsSWEETs were tissue-specific. It also revealed that BsSWEET10 and BsSWEET18 were responsive to low temperature and oxidative stresses. In addition, subcellular localization study indicated that BsSWEET15 and BsSWEET16 were localized in the cell membrane. This study provided important clues for the in-depth elucidation of the sugar transport mechanism of BsSWEET genes and their functional roles in response to abiotic stresses.

Comprehensive functional analysis of the PYL-PP2C-SnRK2s family in Bletilla striata reveals that BsPP2C22 and BsPP2C38 interact with BsPYLs and BsSnRK2s in response to multiple abiotic stresses.

As the core regulation network for the abscisic acid (ABA) signaling pathway, the PYL-PP2C-SnRK2s family commonly exists in many species. For this study, a total of 9 BsPYLs, 66 BsPP2Cs, and 7 BsSnRK2s genes were identified based on the genomic databases of Bletilla striata, which were classified into 3, 10, and 3 subgroups, respectively. Basic bioinformatics analysis completed, including the physicochemical properties of proteins, gene structures, protein motifs and conserved domains. Multiple cis-acting elements related to stress responses and plant growth were found in promoter regions. Further, 73 genes were localized on 16 pseudochromosomes and 29 pairs of paralogous genes were found via intraspecific collinearity analysis. Furthermore, tissue-specific expression was found in different tissues and germination stages. There were two BsPYLs, 10 BsPP2Cs, and four BsSnRK2 genes that exhibited a difference in response to multiple abiotic stresses. Moreover, subcellular localization analysis revealed six important proteins BsPP2C22, BsPP2C38, BsPP2C64, BsPYL2, BsPYL8, and BsSnRK2.4 which were localized in the nucleus and plasma membrane. Finally, yeast two-hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) assays suggested that BsPP2C22 and BsPP2C38 could interact with multiple BsPYLs and BsSnRK2s proteins. This study systematically reported on the identification and characterization of the PYL-PP2C-SnRK2s family in B. striata, which provided a conceptual basis for deep insights into the functionality of ABA core signal pathways in Orchidaceae.

Are Older Adults More Optimistic? Evidence From China, Israel, and the United States.

OBJECTIVES: Optimistic bias refers to the phenomenon that individuals believe bad things are less likely to happen to themselves than to others. However, whether optimistic bias could vary across age and culture is unknown. The present study aims to investigate (a) whether individuals exhibit optimistic bias in the context of coronavirus disease 2019 (COVID-19) pandemic, and (b) whether age and culture would moderate such bias. METHOD: 1,051 participants recruited from China, Israel, and the United States took the online survey. Risk perceptions consist of 3 questions: estimating the infected probability of different social distance groups (i.e., self, close others, and nonclose others), the days that it would take for the number of new infections to decrease to zero and the trend of infections in regions of different geographical distances (i.e., local place, other places inside participants' country, and other countries). Participants in China and the United States also reported their personal communal values measured by Schwartz's Value Survey. RESULTS: Results from Hierarchical Linear Modeling generally confirmed that (a) all participants exhibited optimistic bias to some extent, and (b) with age, Chinese participants had a higher level of optimistic bias than the Israeli and U.S. participants. Compared to their younger counterparts, older Chinese are more likely to believe that local communities are at lower risk of COVID-19 than other countries. DISCUSSION: These findings support the hypothesis that age differences in risk perceptions might be influenced by cultural context. Further analysis indicated that such cultural and age variations in optimistic bias were likely to be driven by age-related increase in internalized cultural values.

Benefits of Grandparental Caregiving in Chinese Older Adults: Reduced Lonely Dissatisfaction as a Mediator.

OBJECTIVE: The purpose of the present study is twofold: (1) to investigate the differences in terms of physical and mental health between those who provide grandparental care and those who do not and (2) to explore the mechanism that connects grandparental caregiving and health-related outcomes. METHODS: Two studies (a cross-sectional and a short-term longitudinal follow-up) were conducted. The cross-sectional study (Study 1) examined 148 older adults who provided grandparental care and another 150 older adults who did not. A small longitudinal follow-up study (Study 2) was conducted among 102 older adults randomly selected from Study 1, of which 52 were older adults who provided grandparental care, and another 50 older adults were those who did not. Health status (measured by SF-36), lonely dissatisfaction (measured by Lonely Dissatisfaction Subscale of PGC-MS), and cognitive functions (measured by subscales of WAIS) as well as demographics were measured in both studies. RESULTS: Results of both the cross-sectional and longitudinal studies showed that, compared with older adults who did not provide grandparental care, those providing grandparental care had significantly better physical and mental health as well as reduced lonely dissatisfaction. Further path analysis showed that lonely dissatisfaction mediated the association between providing grandparental care and enhancement in functions such that providing grandparental care could reduce lonely dissatisfaction, which, in turn, could improve their physical and mental health even after controlling for their cognitive functions. DISCUSSION: These results suggest that providing grandparental care can improve older adults' physical and mental health through reduced lonely dissatisfaction.