Transcriptome analysis of gene expression in the tomato leaf premature senescence mutant.

Premature senescence of leaves can critically influence tomato yield and quality. In this study, the leaf premature senescence mutant MT318 was a spontaneous mutant and was controlled by a single recessive nuclear gene. The maximum photochemical efficiency (Fv/Fm), superoxide dismutase (SOD), and chlorophyll content in the leaves of mutant MT318 gradually decreased, while malondialdehyde (MDA) content significantly increased. Under the level 2 category, Gene Ontology (GO) enrichment analysis indicated that 45 terms were enriched, comprising 22 in biological process, 12 in cellular component, and 11 in molecular function. Genes are mainly involved in the metabolic processes (696 differentially expressed genes, DEGs), cellular processes (573 DEGs), single-organism processes (503 DEGs), and catalytic activity (675 DEGs). Kyoto Encyclopedia of Genes and Genomes pathway analysis demonstrated that the 4 pathways with the largest number of genes were biosynthesis of secondary metabolites, plant-pathogen interaction, plant hormone signal transduction, and MAPK signaling pathway-plant. The 'plant hormone signal transduction' pathway was the most significantly enriched at the T2 stage. Pearson correlation analysis showed that the auxin regulatory pathway and SA signal transduction pathway may play important roles. These results not only lay the foundation for the further cloning and functional analysis of the MT318 premature senescence gene but also provide a reference for the study of tomato leaf senescence. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-022-01223-2.

Effects of supplemental light on tomato growth and the mechanism of the photosystem II apparatus.

The addition of supplemental light (SL) is an effective way to offset insufficient lighting. Although it is commonly believed that SL increases leaf photosynthesis and therefore improves yield and fruit flavor, the mechanism underlying the effects of SL on the photosystem II (PSII) apparatus remains unclear, and SL leads to high energy consumption. In order to save energy, we investigated the physiological status of the PSII apparatus, plant growth parameters and fruit parameters under two types of overhead SL with a low daily energy consumption of 0.0918 kWh m-2. The results showed that SL significantly increased the leaf chlorophyll content from full unfolding to yellowing. However, a remarkable increase in the absorption flux per cross-section (ABS/CS), the quantum yield of electron transport (φEo) and the performance index (PIabs) was observed only in a relatively short period of the leaf life cycle. SL also enhanced the fruit yield and quality. The obviously increased ΔVK and ΔVJ components of the chlorophyll fluorescence induction kinetic (OJIP) curve, along with the significantly decreased PIabs from days 40-60 after unfolding in the SL-treated groups, resulted in more rapid leaf aging and earlier fruit ripening compared with the control plants (CK). Therefore, an energy-friendly SL strategy can alter the physiological status of the PSII apparatus, affecting yield and fruit quality and maturity.

A bibliometric analysis of preoperative anxiety research (2001-2021).

Recently, mental health has received increasing attention, particularly preoperative anxiety, which constitutes a bad emotional experience for surgical patients. Many experts have studied preoperative anxiety in terms of its related risk factors, interventions, and postoperative effects; however, there has been no systematic analysis of published articles. This paper presents a bibliometric review of documents related to preoperative anxiety published between 2001 and 2021. A detailed data analysis of 1,596 publications was conducted using CiteSpace and VOSviewer. Since the 20th century, the field of preoperative anxiety has gradually developed; research began around 2000 and has made a huge leap forward since 2016. Developed countries, led by the United States, were the first to conduct research, but preoperative anxiety research in developing countries like Turkey and China has gradually increased and led to an irreplaceable contribution. Intervention has remained the main topic of preoperative anxiety research, and measures have developed from premedication to the provision of education and information. Moreover, the use of advanced equipment such as virtual reality has emerged with great popularity. Based on previous research, the application of virtual reality combined with pediatric patients will become a new research direction.