ABSTRACT
In this study, we aimed to assess the effect of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection on semen parameters. The study comprised 110 sperm volunteers who self-reported SARS-CoV-2 infection from the Human Sperm Bank of the Center for Reproductive Medicine, Shandong University (Jinan, China). The volunteers had normal sperm concentration before infection. Each volunteer provided semen samples before and after infection. We selected 90 days after infection as the cutoff point. Semen parameters within 90 days after infection of 109 volunteers (group A) were compared with semen parameters before infection. Moreover, semen parameters on or after 90 days after infection of 36 volunteers (group B) were compared with semen parameters before infection. Furthermore, based on whether the volunteers had completed the three-dose SARS-CoV-2 vaccination booster, volunteers in group A and B were further divided into two subgroups separately. Semen parameters were compared before and after infection in each subgroup. Our results showed that in this cohort population, the semen quality in volunteers with normal sperm concentrations before infection decreased after SARS-CoV-2 infection within 90 days, while the semen quality returned to preinfection levels after 90 days. The completion of a three-dose SARS-CoV-2 vaccination booster may exert a protective effect on semen quality after infection.
ABSTRACT
Fruit peel creasing is a serious pre-harvest physiological disorder in citrus, influencing fruit quality, storage, and yield. Four- and eight-year-old 'Hongjiang' oranges grafted onto Canton lemon rootstocks were treated with calcium and calcium inhibitors, respectively, to study the effects of different treatments on fruit creasing rate, mechanical properties of the peel, cell wall metabolism enzyme activities, and the expression of related genes. Foliar application of 0.5% calcium nitrate significantly reduced the fruit creasing rate, while treatment with EGTA and LaCl3, inhibitors of calcium uptake, increased the fruit creasing rate; But the effect of calcium nitrate treatment on changing the mechanical properties of pericarp and inhibiting the activity of hydrolase (PG, Cx and PE) was not very significant. Furthermore, it was observed that the expression levels of genes (PG, Cx, and PE) encoding cell wall-degrading enzymes were significantly lower in the normal fruit peel than in the creased fruit peel. Meanwhile, the expression levels of PG, Cx, and PE were higher in the peel of shaded fruit than in the peel of exposed fruit. During the high incidence period of fruit creasing, calcium nitrate treatment down-regulated the expression of PG, Cx, and PE, while EGTA treatment up-regulated the expression of these genes. In conclusion, foliar spraying of calcium nitrate at the fruit rapid enlargement stage can increase the Ca content in the peel of 'Hongjiang' orange and significantly suppress the expression of cell wall degrading enzymes genes (PG, PE and Cx) in 'Hongjiang' orange peel during the high occurrence period of fruit creasing, resulting in reducing the occurrence of fruit creasing and cracking.
