No abstract

No abstract

A high concentration of brassinolide (BL) induced abnormal shoot shape in rice seedlings, that is, the newly developed leaf sheath was shorter than the old sheath, and increased the number of leaves. The involvement of ethylene and cyanide, co-metabolites during ethylene biosynthesis, in abnormal shoot growth was analyzed by comparing the action mechanism of BL with that of quinclorac in barnyard grass seedlings. BL strongly stimulated ethylene production, and the amount of ethylene and the third leaf sheath length in rice seedlings were negatively correlated. Exogenously applied ethephon also induced abnormal growth of rice seedlings. L-a -aminoethoxyvinyl-glycine (AVG), an ethylene biosynthetic inhibitor, partially reversed abnormal shoot growth. The level of endogenous cyanide was low in rice seedlings, because of the high level of b-cyanoalanine synthase (CAS) activity, and exogenously applied KCN did not induce abnormal shoot growth. The results indicate that BL-induced abnormal shoot growth of rice seedlings was probably mediated by ethylene production.

A polystyrene microdevice on which sample pre-concentration and subsequent amplification functionalities were integrated was fabricated for the detection of a foodborne pathogen, Escherichia coli O157:H7, in raw milk.

Rhodotorula is a genus of marine yeasts that is considered the most suitable for carotenoid production. In this study, collected soils at Kien Giang and Tra Vinh provinces were cultured on yeast extract peptone dextrose (YEPD) agar for 72 hours at room temperature. Twenty-three isolates exhibiting yellow, orange, and pink pigments were tested for physiological and biochemical characteristics such as carbohydrate fermentation and assimilation, nitrate assimilation, urease production, and growth temperature. Their oval dimensions were 4.24x3.64 μm for isolate 5S1-T and 3.88x3.17 μm for isolate 5S4-T. The two isolates could assimilate carbohydrate and nitrate sources and produce urease. The ITS rDNA sequence of isolates 5S1-T and 5S4-T both had 100% matches to Rhodotorula sphaerocarpaCBS:5940 and Rhodotorula sphaerocarpa CBS:5939, respectively. The maximum absorbance wavelengths of the solution extractions from the 5S1-T and 5S4-T were 496 and 487 nm, respectively. The total carotenoid content of strain 5S1-T was found to be the highest (1.81 mg/l) followed by strain 5S4-T (1.16 mg/ml). The antioxidant abilities of the 5S1-T and 5S4-T were demonstrated by scavenging the free radical DPPH and ferric reducing capacity. The free radical scavenging activity of the extract from isolate 5S1-T (96.15%) was higher than that of isolate 5S4-T (88.61%) at 0.14 mg/ml. The absorbance at 700 nm of the extracts of both 5S1-T and 5S4-T significantly increased from 0.05 to 0.3 mg/ml. The two strains 5S1-T and 5S4-T of Rhodotorulasphaerocarpa discovered in this study could contribute to carotenoid and antioxidant-producing yeasts for industries in the future.