Transcriptome analysis reveals antioxidant defense mechanisms in the red swamp crayfish Procambarus clarkia after exposure to chromium.

Chromium (Cr) as a chromate anion has a strong redox capacity that seriously threatens the ecological environment and human health. Cr can contaminate water and impart toxicity to aquatic species. Procambarus clarkii is an important food source that once represented a large proportion of the aquaculture industry due to its rapid reproduction and high economic value.

[Physiological responses and tolerance to drought stress of different watermelon genotypes.].

With the continuous drought stress treatment to 12 pot-grown watermelon genotypes originated from different regions, the influence of drought stress on plant height, root length, fresh mass and dry mass was studied, and the physiological responses of these genotypes to drought stress were compared. Drought resistance of these watermelon genotypes was preliminarily determined according to the drought injury, and then confirmed by membership function evaluation method. We found that the watermelon genotypes exhibited great difference in drought tolerance based on the occurrence of drought injury and the degree of injury severity.

Two new steroidal saponins from Tribulus terrestris.

Two new steroidal saponins and two known flavonoid glycosides were isolated from the fruits of Tribulus terrestris. Their structures were assigned by spectroscopic analysis and chemical reaction as 26-O-beta-D-glucopyranosyl-(25R)-5 alpha-furostan-12-one-3beta,22 alpha,26-triol-3-O-beta-D-glucopyranosyl (1 --> 2)-beta-D-glucopyranosyl(1 --> 4)-beta-D-galactopyranoside (1), 26-O-beta-D-glucopyranosyl-(25S)-5 alpha-furostan-22-methoxy-2 alpha,3beta,26-triol-3-O-beta-D-glucopyranosyl(1 --> 2)-beta-D-glucopyranosyl(1 --> 4)-beta-D-galactopyranoside (2), kaempferol-3-gentiobioside (3), and isorhamnetin-3-gentiobioside (4).