Accumulation and tolerance characteristics of cadmium in Chlorophytum comosum: a popular ornamental plant and potential Cd hyperaccumulator.

The effects on the growth, physiological indexes and the cadmium (Cd) accumulation in Chlorophytum comosum under Cd stress were examined by pot-planting. The results showed that the tolerance index (TI) of C. comosum were all above 100 in soil Cd concentration of 100 mg kg(-1). The O(2˙)⁻ production rate and electrical conductivity of C. comosum were significantly positively correlated to Cd adding-concentration while the MDA content increased and had significant differences with the control. The activities of SOD, CAT, and POD all rose significantly in lower Cd concentration and the Cd threshold of them were around 10, 50 and 20 mg kg(-1), respectively. The Cd in C. comosum root and aboveground part reached 1,522 and 865·5 mg kg(-1), respectively, in Cd concentration of soil up to 200 mg kg(-1). For the advantages of high tolerance, high accumulation, and high ornamental value, C. comosum may have tremendous application value in the treatment of Cd-contaminated soils.

Diversity of endophytic fungi of Paeonia lactiflora Pallas and screening for fungal paeoniflorin producers.

Endophytic fungi from Paeonia lactiflora Pallas, which is mainly distributed in China, were characterized and screened to identify those capable of producing paeoniflorin. A total of 101 isolates obtained from the roots, stems and leaves of P. lactiflora were grouped into 16 fungal taxa based on morphological traits and internal transcribed spacers sequences, indicating that endophytic fungi of P. lactiflora are abundant and diverse. The dominant endophytic fungi were Aspergillus, Alternaria and Penicillium. More fungi were recovered from leaves than from roots and stems. The similarity index was highest between the stems and leaves (0.733), followed by the roots and leaves (0.615) and the stems and roots (0.563). Analyses of the fermentation extracts of 22 endophytic fungi by high-performance liquid chromatography and mass spectrometry revealed that three strains (R12, Alternaria tenuissima; S4, Aspergillus flavus; and R17 Penicillium commune) were able to produce paeoniflorin. Among the paeoniflorin-producing fungi, the yield of paeoniflorin from A. flavus S4 was 342.4 µg/L, and this strain could be used as a candidate for the industrial production of paeoniflorin.