Two rice varieties, Xiushui 110 with high cadmium (Cd) tolerance and Xiushui 11 with low Cd tolerance were used to study the effects of Cd stress on seed germination, seedling growth and amylase activities. The low cadmium concentration had little effect on seed germination rate. However, cadmium stress could significantly inhibit plumule and radicle growth, especially for radicle growth. Germination index, vigour index, radicle length and amylase activities of Xiushui 11 decreased more significantly with the increasing cadmium level compared with Xiushui 110. The cadmium content in seedlings of Xiushui 11 was higher than that in Xiushui 110 when the cadmium concentration exceeded 5 μmol/L, which caused lower mitotic index in root tips and amylase activities, and more serious cadmium toxicity in Xiushui 11.
Six alkaloids,2-(1H-indol-3-yl)-4H-benzo[d]oxazin-4-one(1),methyl o-(indole-3-carboxamido) benzoate(2),cyclo(Ile-Leu-Val-Va1)(3),cyclo(Phe-Gly)(4),cyclo(Leu-Leu)(5),and cyclo(Ala-Leu)(6),were isolated from the mangrove endophytic fungus ZSU-H26 from the South China Sea.Their structures were elucidated by spectral data.Indole alkaloids 1 and 2 were both isolated from microorganism for the first time.In the preliminary bioassay,1 and 2 show inhibitory activity on the hepG2 cell line with IC50 values of 20μg/mL and 35μg/mL,respectively.
