SENSITIVE TO FREEZING2 is crucial for growth of Marchantia polymorpha under acidic conditions.

Land plants have evolved many systems to adapt to a wide range of environmental stresses. In seed plants, oligogalactolipid synthesis is involved in tolerance to freezing and dehydration, but it has not been analyzed in non-vascular plants. Here we analyzed trigalactosyldiacylglycerol (TGDG) synthesis in Marchantia polymorpha. TGDG is synthesized by galactolipid: galactolipid galactosyltransferase [GGGT; SENSITIVE TO FREEZING2 (SFR2) in Arabidopsis]. We analyzed the subcellular localization and GGGT activity of two M. polymorpha SFR2 homologs (MpGGGT1 and MpGGGT2, each as a GFP-fusion protein) using a transient expression system in Nicotiana benthamiana leaves and found that MpGGGT1-GFP localized in the chloroplast envelope membrane. We produced mutants Mpgggt1 and Mpgggt2 and found that TGDG did not accumulate in Mpgggt1 upon treatment of the thallus with acetic acid. Moreover, growth of Mpgggt1 mutants was impaired by acetic acid treatment. Microscopy revealed that the acetic acid treatment of M. polymorpha plants damaged intracellular membranes. The fact that the effect was similar for wild-type and Mpgggt1 plants suggested that MpGGGT has a role in recovery from damage. These results indicate that MpGGGT plays a crucial role in M. polymorpha growth under conditions of acid stress, which may have been encountered during the ancient terrestrial colonization of plants.

Surgical antimicrobial prophylaxis in Japanese hospitals: Real status and challenges.

BACKGROUND: Information regarding the status of surgical antimicrobial prophylaxis (SAP) in Japanese hospitals is lacking. This study aimed to explore the status of SAP prescriptions for surgeries and adherence to Japanese SAP guidelines. METHODS: From February to July 2020, a 1-day multicentre point prevalent survey was conducted at 27 hospitals in Aichi Prefecture, Japan. Patients prescribed SAP were included in this study. The appropriateness of the SAP was evaluated based on the guidelines for selection of antimicrobials and their duration. Surgery was defined as appropriate when all the items were appropriate. RESULTS: A total of 728 patients (7.1 %; 728/10,199) received antimicrobials for SAP. Among them, 557 patients (76.5 %, 557/728) underwent the surgeries described in the guidelines. The overall appropriateness of all surgeries was 33.9 % (189/557). The appropriate selection of antimicrobial before/during and after surgery and their durations were 67.5 % (376/557), 67.5 % (376/557), and 43.3 % (241/557), respectively. The overall appropriateness ranged from 0 % (0/37, oral and maxillofacial surgery) to 58.7 % (88/150, orthopaedic surgery) and 27.7 % (36/130, community hospitals with 400-599 beds) to 47.2 % (17/36, specific hospitals). Cefazolin was the most prevalent antimicrobial prescribed before/during (55.5 %, 299/539), and after (45.1 %, 249/552) surgery. In total, 101 oral antimicrobials were prescribed postoperatively. CONCLUSIONS: SAP adherence by specific surgical fields and hospitals was shown in this study. Intensive intervention and repeated surveillance are necessary to improve SAP prescriptions in Japanese hospitals.