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Chromium (Cr) in the soil is one of the major pollutants for agricultural production. This study examined the efficiency of sunflower plants to remediate Cr-contaminated soils using a plant growth regulator, 5-aminolevolinic acid (ALA). At six leaf stage, sunflower plants were exposed to soil-applied Cr (0.15 g kg−1), manganese (Mn, 0.3 g kg−1) and trisodium (S,S)-ethylenediamine-N,N′-disuccinic acid (EDDS, 2.5 mmol kg−1), ALA (10 mg L−1) was sprayed. After ALA treatment, the plants were harvested for further biochemical analyses. Results showed that EDDS and Mn improved the Cr accumulation but restrained plant growth. Conversely, ALA improved the growth of Cr-stressed plants by promoting chlorophyll concentration in the top fully expanded leaves. The bioaccumulation quantity and removal efficiency of sunflowers treated by Cr + EDDS + ALA was improved by 47.92% and 47.94%, respectively, as compared to the Cr treatment. This was further supported by qRT-PCR analysis, where the expression of heavy metal transport genes such as ZIP6 and NRAMP6 and subsequently Cr accumulation in sunflower tissues increased by EDDS, Mn, and ALA application. However, compared with other treatments, ALA ameliorated cellular injury from Cr-stress by uptake or movement of Cr prevention, modulation of antioxidant enzymes, and elimination of reactive oxygen species. Our study suggested that ALA as an ideal option for the phytoremediation of Cr-contaminated soils. The research was sponsored by the Science and Technology Program of Zhejiang Province (2022C02034), and Fundamental Research Funds of Zhejiang Sci-Tech University (14042216-Y). We thank Dr. Li Xie at Bio-ultrastructure Analysis Laboratory of Analysis Center of Agrobiology and Environmental Sciences, Zhejiang University. We also thank Rui Sun from the Agricultural Experiment Station of Zhejiang University for his assistance.

To investigate the effect of enteral nutrition (EN) start time on pH value of gastric juice and ventilator-associated pneumonia (VAP) in critically ill patients with invasive mechanical ventilation, so as to provide reference for the rational selection of EN timing.Patients with mechanical ventilation who underwent EN treatment admitted to the intensive care unit (ICU) of the First Affiliated Hospital of Zhengzhou University from January 1st, 2016 to November 30th, 2017 were enrolled, and the inclusion criteria were age ≥ 18 years, acute physiology and chronic health evaluation II (APACHE II) ≤ 15, and nutritional risk screening (NRS 2002) ≥ 3. Patients were divided into two groups according to the start time of EN: early EN group (implementation of EN within 48 hours after mechanical ventilation) and late EN group (implementation of EN after 48 hours after mechanical ventilation). The pH value of gastric juice, VAP incidence, mechanical ventilation time, and the length of ICU stay were compared between the two groups.A total of 108 patients were included, 54 in the early EN group and 54 in the late EN group respectively. The pH value of gastric juice in early EN group was lower than that in late EN group [4.8 (3.8, 5.8) vs. 5.6 (4.6, 6.6), P0.01]. There were 8 patients with VAP in the early EN group, 3 of whom were early onset VAP. There were 17 patients with VAP in the late EN group, 10 of whom were early onset VAP. The incidence of VAP and the incidence of premature VAP in the early EN group were significantly lower than those in the late EN group (14.8% vs. 31.5%, 5.6% vs. 18.5%, both P0.05). The mechanical ventilation time [days: 7.5 (5.7, 9.0) vs. 8.6 (6.8, 10.7) and the length of ICU stay [days: 10.0 (8.5, 11.7) vs. 11.0 (9.5, 12.6)] in the early EN group were significantly shorter than those in the late EN group (all P0.05).At the same time of protecting gastric mucosa, early EN is helpful to reduce the incidence of VAP, reduce the duration of mechanical ventilation and the length of ICU stay, and improve the prognosis.