RESUMO
14-3-3 proteins are widely distributed in eukaryotic cells and play an important role in plant growth, development, and stress tolerance. This study revealed nine 14-3-3 genes from the genome of Nitraria sibirica Pall., a halophyte with strong salt tolerance. The physicochemical properties, multiple sequence alignment, gene structure and motif analysis, and chromosomal distributions were analyzed, and phylogenetic analysis, cis-regulatory elements analysis, and gene transcription and expression analysis of Ns14-3-3s were conducted. The results revealed that the Ns14-3-3 gene family consists of nine members, which are divided into two groups: ε (four members) and non-ε (five members). These members are acidic hydrophilic proteins. The genes are distributed randomly on chromosomes, and the number of introns varies widely among the two groups. However, all genes have similar conserved domains and three-dimensional protein structures. The main differences are found at the N-terminus and C-terminus. The promoter region of Ns14-3-3s contains multiple cis-acting elements related to light, plant hormones, and abiotic stress responses. Transcriptional profiling and gene expression pattern analysis revealed that Ns14-3-3s were expressed in all tissues, although with varying patterns. Under salt stress conditions, Ns14-3-3 1a, Ns14-3-3 1b, Ns14-3-3 5a, and Ns14-3-3 7a showed significant changes in gene expression. Ns14-3-3 1a expression decreased in all tissues, Ns14-3-3 7a expression decreased by 60% to 71% in roots, and Ns14-3-3 1b expression increased by 209% to 251% in stems. The most significant change was observed in Ns14-3-3 5a, with its expression in stems increasing by 213% to 681%. The yeast two-hybrid experiments demonstrated that Ns14-3-3 5a interacts with NsVP1 (vacuolar H+-pyrophosphatase). This result indicates that Ns14-3-3 5a may respond to salt stress by promoting ionic vacuole compartmentalization in stems and leaves through interactions with NsVP1. In addition, N. sibirica has a high number of stems, allowing it to compartmentalize more ions through its stem and leaf. This may be a contributing factor to its superior salt tolerance compared to other plants.
Assuntos
Magnoliopsida , Estresse Salino , Filogenia , Estresse Salino/genética , Tolerância ao Sal/genética , Íntrons/genética , Proteínas 14-3-3/genética , Pirofosfatase Inorgânica , Proteínas de Plantas/genética , Regulação da Expressão Gênica de Plantas , Estresse Fisiológico/genéticaRESUMO
Bike sharing, as an innovative travel mode featured by mobile internet and sharing, offers a new transport mode for short trips and has a huge positive impact on urban transportation and environmental protection. However, bike-sharing operators face some operational challenges, especially in sustainable development and profitability. Studies show that the customers' willingness to pay is a key factor affecting bike-sharing companies' operating conditions. Based on the theories of perceived value, this study conducts an empirical analysis of factors that affect bike-sharing users' willingness to pay for bike-sharing through measurement scales, user surveys, and structural equation models. We designed a five-point Likert-type scale containing 11 latent variables affecting willingness to pay and a total of 34 measurement items. We investigate bike-sharing users in China's first and second-tier cities, with a total of 502 participants. The results show that perceived value, payment awareness, trust, and environmental awareness constitute key factors that directly affect bike-sharing users' willingness to pay. And perceived usefulness, perceived ease-of-use, perceived cost, and perceived risk indirectly affect bike-sharing users' willingness to pay. However, we found no significant effects of perceived entertainment on perceived value or word of mouth on willingness to pay. Our results are expected to provide theoretical and practical implications for bike-sharing programs.