Auxin plays a role in the adaptation of rice to anaerobic germination and seedling establishment.

Auxin is well known to stimulate coleoptile elongation and rapid seedling growth in the air. However, its role in regulating rice germination and seedling establishment under submergence is largely unknown. Previous studies revealed that excessive levels of indole-3-acetic acid(IAA) frequently cause the inhibition of plant growth and development. In this study, the high-level accumulation of endogenous IAA is observed under dark submergence, stimulating rice coleoptile elongation but limiting the root and primary leaf growth during anaerobic germination (AG). We found that oxygen and light can reduce IAA levels, promote the seedling establishment and enhance rice AG tolerance. miRNA microarray profiling and RNA gel blot analysis results show that the expression of miR167 is negatively regulated by submergence; it subsequently modulates the accumulation of free IAA through the miR167-ARF-GH3 pathway. The OsGH3-8 encodes an IAA-amido synthetase that functions to prevent free IAA accumulation. Reduced miR167 levels or overexpressing OsGH3-8 increase auxin metabolism, reduce endogenous levels of free IAA and enhance rice AG tolerance. Our studies reveal that poor seed germination and seedling growth inhibition resulting from excessive IAA accumulation would cause intolerance to submergence in rice, suggesting that a certain threshold level of auxin is essential for rice AG tolerance.

Rapid and efficient isolation platform for plasma extracellular vesicles: EV-FISHER.

Extracellular vesicles (EVs) have found diverse applications in clinical theranostics. However, the current techniques to isolate plasma EVs suffer from burdensome procedures and limited yield. Herein, we report a rapid and efficient EV isolation platform, namely, EV-FISHER, constructed from the metal-organic framework featuring cleavable lipid probes (PO4 3- -spacer-DNA-cholesterol, PSDC). The EV-FISHER baits EVs from plasma by cholesterol and separates them with an ordinary centrifuge. The captured EVs could be released and collected upon subsequent cleavage of PSDC by deoxyribonuclease I. We conclude that EV-FISHER dramatically outperforms the ultracentrifugation (UC) in terms of time (∼40 min vs. 240 min), isolation efficiency (74.2% vs. 18.1%), and isolation requirement (12,800 g vs. 135,000 g). In addition to the stable performance in plasma, EV-FISHER also exhibited excellent compatibility with downstream single-EV flow cytometry, enabling the identification of glypican-1 (GPC-1) EVs for early diagnosis, clinical stages differentiation, and therapeutic efficacy evaluation in breast cancer cohorts. This work portrays an efficient strategy to isolate EVs from complicated biological fluids with promising potential to facilitate EVs-based theranostics.

Effects of Elevated Ozone Concentrations on Root Characteristics and Soil Properties of Elaeocarpus sylvestris and Michelia chapensis.

The increasing concentration of surface ozone (O3) was observed during recent decades in the world, which affects tree roots and forest soils. Meanwhile, the impact of ozone on tree roots is greatly affected by soil condition. However, there is a lack of knowledge about the possible effects of ozone on tree roots and soil processes. In this study, The influences of surface ozone (O3) stress on the root biomass, morphology, nutrients, soil properties, and soil enzyme activity of Elaeocarpus sylvestris and Michelia chapensis seedlings were examined at four O3 concentrations (charcoal-filtered air, 1 × O3 air, 2 × O3 air, and 4 × O3 air). Elevated O3 concentrations were found to significantly increase the root C content, N content, C/P ratio, and N/P ratio, and significantly decrease the root biomass, number of root tips, and root C/N ratio of both species. The soil organic matter content, pH, total N content, and urease and catalase activities of both species tended to increase. The limitation in root growth and responses in the root structure of E. sylvestris induced by elevated O3 concentrations led to increased bulk density and decreased soil porosity and void ratio. These profound effects of O3 concentrations on the roots and soil characteristics of these two species underscore the importance of research in O3 science.

Changes of Cinnamomum camphora root characteristics and soil properties under ozone stress in South China.

High O3 exposure affects the forest growth and soil characteristics. Although there is substantial evidence that O3 does impose a stress on forest trees, the effects of O3 on roots and soil of evergreen broad-leaved tree species in South China remain unknown. The effects of ozone (O3) fumigation on the root biomass, root morphology, root nutrient, soil physical, and chemical properties were examined in Cinnamomum camphora seedlings grown under four O3 treatments (charcoal-filtered air (CF) or O3 at 1×, 2× and 4× ambient concentration). O3 significantly decreased root biomass and root carbon (C). Regardless of O3 level, elevated O3 significantly resulted in reduced root surface area, volume, number of forks, and specific root length (SRL). The percentages of fine to total root in terms of root surface area and root volume of seedlings under the CF and 1 × O3 treatments were significantly higher than those of seedlings under the 4 × O3 treatment, indicating that high O3 level impaired the growth performance of fine roots. O3 affected root growth and structures, which increased soil bulk density and reduced soil total porosity and void ratio. The soil pH under all O3 fumigation treatments significantly increased compared with CF treatment, whereas the organic matter significantly decreased. In conclusion, although the increased O3 level enhanced root N and P under 2 and 4 × O3 treatments compared with 1 × O3 treatment as compensation mechanisms to prevent O3-induced decrease in root C gain and root functions, O3 still decreased the root biomass and root tips, and changed the soil physical and chemical properties.