Salicylic Acid Treatment Alleviates the Heat Stress Response by Reducing the Intracellular ROS Level and Increasing the Cytosolic Trehalose Content in Pleurotus ostreatus.

Pleurotus ostreatus is usually cultivated in horticultural facilities that lack environmental control systems and often suffer heat stress (HS). Salicylic acid (SA) is recognized as a plant defense-related hormone. Here, SA treatment (200 µM) induced fungal resistance to HS of P. ostreatus, with decreased malondialdehyde (MDA) content and HSP expression. Further analysis showed that SA treatment in P. ostreatus increased the cytosolic trehalose content and reduced the intracellular reactive oxygen species (ROS) level. Moreover, H2O2 could restore the MDA content and HSP expression of P. ostreatus treated with SA under HS. In addition, trehalose (25 mM) or CaCl2 (5 mM) treatment induced fungal resistance to HS, and CaCl2 treatment increased the cytosolic trehalose content of P. ostreatus under HS. However, inhibiting Ca2+ levels using Ca2+ inhibitors or mutants reversed the trehalose content induced by SA in P. ostreatus under HS. In addition, inhibiting trehalose biosynthesis using Tps-silenced strains reversed the MDA content and HSP expression of P. ostreatus treated with SA under HS. Taken together, these results indicate that SA treatment alleviates the HS response of P. ostreatus by reducing the intracellular ROS level and increasing the cytosolic trehalose content. IMPORTANCE Heat stress (HS) is a crucial environmental challenge for edible fungi. Salicylic acid (SA), a plant defense-related hormone, plays key roles in plant responses to biotic and abiotic stresses. In this study, we found that SA treatment increased the cytosolic trehalose content and induced fungal resistance to HS in P. ostreatus. Further analysis showed that SA can alleviate the HS of P. ostreatus by reducing the intracellular ROS level and increasing the cytosolic trehalose content. Our results help to understand the mechanism underlying the responses of P. ostreatus to HS. In addition, this research provides new insights for the cultivation of P. ostreatus.

A case of vitiligo cured with cucumber and sulfur.

This study investigates a 42-year-old man who used sulfur powder adhered to cucumber slices to successfully self-treat a vitiligo condition. The treatment has resulted in no recurrence of the disease for 21 years. We analyzed the mechanism of this folk prescription for vitiligo, concluding that the success of the self-treatment may be mainly associated with hydrogen sulfide (H2 S). The antibacterial activity of pentathionic acid (H2 S5 O6 ) and the antioxidant activity of cucumber might also play a role in the treatment.

Downregulation of Ethylene Production Increases Mycelial Growth and Primordia Formation in the Button Culinary-Medicinal Mushroom, Agaricus bisporus (Agaricomycetes).

Ethylene biosynthesis and function in Agaricus bisporus (the button mushroom) remain uncertain. The enzyme activities of 1-aminocyclopropane-1-carboxylate (ACC) synthase (ACS) and ACC oxidase (ACO) were detectable in A. bisporus AS2796 and inhibited by α-aminooxyacetic acid and Co2+. We cloned and sequenced 2 ACS genes (Ab-ACS1 and Ab-ACS2) and 1 ACO gene (Ab-ACO) from the mushroom strain. Ab-ACS1 and Ab-ACS2 demonstrated low amino acid sequence similarity. Ab-ACO demonstrated an amino acid sequence completely identical to that of ACO1_AGABI from A. bisporus. Antisense ACO significantly reduced ACO gene expression level, ACO enzyme activity, and ethylene production in the mushroom transformants. The transformants grew faster than the wild-type strain in sterilized compost and normally formed primordia when cultivated in sterilized compost with the sterilized casing vermiculite, but the wild-type strain did not. Our results show that ethylene is synthesized in button mushrooms via the ACC pathway. Ethylene inhibited button mushroom mycelial growth and development.

Effect of tao-hong-si-wu-tang, a traditional Chinese herbal medicine formula, on physical fatigue in mice.

Tao-Hong-Si-Wu-Tang (THSWT) is a famous traditional Chinese herbal medicine formula, which has traditionally been used in China for about one thousand years. The present study investigated the effect of THSWT on physical fatigue. 32 male mice were randomly divided into 4 groups with 8 in each group. All were administered orally and daily for 28 days. Group I received isotonic saline solution as control; Group II, III and IV obtained 5, 10 and 20ml/ kg body weight of THSWT solutions, respectively. After 28 days, the anti-physical fatigue effect of THSWT was evaluated by using a forced swimming test, along with the determination of blood lactic acid, blood urea nitrogen (BUN), liver glycogen and muscle glycogen contents. The data showed that THSWT could extend exhaustive swimming time of mice, as well as decrease the BLA and BUN contents and increase the liver glycogen and muscle glycogen contents. The results support that THSWT had anti-physical fatigue effect.