Low temperature-induced regulatory network rewiring via WRKY regulators during banana peel browning.

Banana (Musa spp.) fruits, as typical tropical fruits, are cold sensitive, and lower temperatures can disrupt cellular compartmentalization and lead to severe browning. How tropical fruits respond to low temperature compared to the cold response mechanisms of model plants remains unknown. Here, we systematically characterized the changes in chromatin accessibility, histone modifications, distal cis-regulatory elements, transcription factor binding, and gene expression levels in banana peels in response to low temperature. Dynamic patterns of cold-induced transcripts were generally accompanied by concordant chromatin accessibility and histone modification changes. These upregulated genes were enriched for WRKY binding sites in their promoters and/or active enhancers. Compared to banana peel at room temperature, large amounts of banana WRKYs were specifically induced by cold and mediated enhancer-promoter interactions regulating critical browning pathways, including phospholipid degradation, oxidation, and cold tolerance. This hypothesis was supported by DNA affinity purification sequencing, luciferase reporter assays, and transient expression assay. Together, our findings highlight widespread transcriptional reprogramming via WRKYs during banana peel browning at low temperature and provide an extensive resource for studying gene regulation in tropical plants in response to cold stress, as well as potential targets for improving cold tolerance and shelf life of tropical fruits.

Genome-wide identification of FAD gene family and their contributions to the temperature stresses and mutualistic and parasitic fungi colonization responses in banana.

Fatty acid desaturase (FAD) plays important roles in plant growth and development and plant defense processes. In this study, we identified 27 MaFAD genes from the banana genome. According to the amino acid sequence similarities, their encoded proteins could be classified into five subfamilies. This classification is consistently supported by their gene and protein structures, conserved motifs and subcellular localizations. Segmental duplication events were found to play predominant roles in the MaFAD gene family expansion. Thirty miRNAs targeting MaFADs were identified and many hormone- and stress-responsive cis-acting elements and transcription factor binding sites (TFBSs) were identified in their promoters, indicating that the MaFADs expression regulation was very complicated. Gene expression analysis showed that some MaFADs showed significant differential expression in response to high and low temperature. FocTR4 influenced greatly the expression of several MaFADs and greatly induced the fatty acid (FA) accumulations in roots. Although S. indica showed no significant influence on the expression of most MaFADs, it could greatly alleviate the influence of FocTR4 on several MaFADs and FA biosynthesis. Our study revealed that MaFADs contributed greatly to the responses of high and low temperature stresses and mutualistic and parasitic fungi colonization in banana.

Implicit support differs across five groups in the U.S., Taiwan, and Mexico.

Objective: Prior research documents numerous psychological and physiological benefits of implicit support particularly for Asians/Asian Americans. However, potential variation in how two different kinds of collectivism-Harmony and Convivial-shape support has been overlooked. Additionally, implicit support has largely been studied using quantitative approaches, whereas qualitative methods may best illuminate how implicit support is used in everyday life. The present mixed-methods investigation aims to better understand implicit support "in practice" and to unpack previously overlooked nuances between different subsets of collectivism in implicit support processes. Method: We collected qualitative accounts of implicit support interactions from 216 female participants (U.S. Whites, U.S. Latinas, U.S. Asians, Mexican, Taiwanese) who were prompted to describe an implicit support experience and then quantitatively assess its helpfulness. Results: Qualitative analysis using a thematic analysis approach identified three subcategories of implicit support (traditional, semi-disclosure, non-verbal cues). Cultural patterns emerged in how implicit support was used across different groups that align with high-context and low-context communication theories and cultural values. Conclusions: The current research highlights the benefit of qualitative approaches to understanding nuanced support processes, and the need to study culture beyond the individualism-collectivism dichotomy. (PsycInfo Database Record (c) 2021 APA, all rights reserved).