Effects of Cadmium Stress on Seed Germination, Seedling Growth and Seed Amylase Activities in Rice (Oryza sativa)

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.

Effects of Exogenous Amylases and Metal Ions on the Amylase Specific Activities and Starch Degradation of the Upper Leaves of ‘KRK_(26)' during Flue-curing

Objective] The aim of this study was to investigate the effects of exoge-nous amylases and Ca2＋, Mn2＋ and K＋ on the amylase specific activities and starch degradation of the upper leaves of ＇KRK26＇ planted in Yunnan Province during flue-curing. [Method] The amylase specific activities and starch degradation of the leaves were determined by using spectrophotometry. [Result] The 8 U/g exogenous α-amy-lase could improve the specific activity of the leaf α-amylase at yel owing and color-fixing stages, but could not at stem-drying stage, and similarly, the 80 U/g exoge-nous β-amylase could improved the specific activity of the leaf β-amylase at the yel owing stage and the early period of color-fixing stage. The leaf starch could be enhanced to degrade by the exogenous α- or β-amylases and the enhancing effect of the former was stronger than that of the later. 1.50 mg/ml Ca2＋ improved the specific activity of the leaf （α＋β）-amylase mainly due to its enhancing effect on the leaf α-amylase, and increased the starch degradation. 4 mmol/L Mn2＋ inhibited the leaf α-amylase from yel owing to the early period of color-fixing and the β- and （α＋β）-amylases from the yel owing to the later period of color-fixing, but enhanced the leafα-amylase from the later period of color-fixing to the later period of stem-drying and the β- and （α＋β）-amylases at the later period of stem-drying. Meanwhile, Mn2＋ ham-pered the starch degradation during yel owing, but promoted it from the early period of color-fixing to stem-drying. 1 mg/ml K＋ enhanced the leaf α-, β- and （α＋β）-amy-lases during the yel owing stage, but lowered them from the early period of color-fix-ing to the later period of stem-drying, and always inhibited the leaf starch degrada-tion. [Conclusion] The exogenous α-, β- amylases and Ca2＋ of suitable concentra-tions could be used to treat the tobacco leaves before flue-curing to improve the leaf starch degradation during the curing.

MICROSTRUCTURE AND AMYLASE ACTIVITY OF CHINESE CABBAGE SEED DURING DRYING PROCESS

A seed is the carrier of life,and research on the heat and mass transfer of a seed has already stridden toward the level of microcosm,such as cell protoplasm,cell organism,and molecular membrane.By means of a transmission electron microscope,the authors of this paper observed the microstructure of cotyledon tissue slices of the Chinese cabbage seed with a moisture content of 13% (on dry basis) and that with a moisture content of 4.3% (on dry basis) for drying 2 h at 45 ℃.The compared result was that only wrinkles had been discovered on the cell walls of the seed dried for 2 h,without any significant change for other organelles.Study on the enzyme activity shows that after a germination for 48 h,the relative activity of α amylase of the Chinese cabbage seed dried for 2 h at 45 ℃,decreased by 5.8%,whereas that of the seed dried 2 h at a temperature of 67 ℃ decreased by 30.1%.This work shows that the drying factors have greatly influence on the seed microstructure,enzyme activity,which is directly positive to seed viability.Combined with the analysis of the critical safe drying temperature of the vegetable seed,it can be concluded that enzyme activity is also the function of the drying temperature,the moisture content and the drying time.

Monitoring salivary amylase activity is useful for providing timely analgesia under sedation

AIM:To detect the criteria and cause of elevated salivary amylase activity(sAMY)in patients undergoing endoscopic submucosal dissection(ESD)under sedation.METHODS:A total of 41 patients with early gastric cancer removed via ESD under deep sedation(DS)were enrolled.The perioperative sAMY,which was shown as sympathetic excitements(SE),was measured.The time at which a patient exhibited a relatively increased rate of sAMY compared with the preoperative baseline level(IR,%)≥100%(twice the actual value)was assumed as the moment when the patient received SE.Among the 41 patients,we focused on 14 patients who exhibited an IR≥100% at any time that was associated with sAMY elevation during ESD(H-group)and examined whether any particular endoscopic procedures can cause SE by simultaneously monitoring the sAMY level.If a patient demonstrated an elevated sAMY level above twice the baseline level,the endoscopic procedure was immediately stopped.In the impossible case of discontinuance,analgesic medicines were administered.This study was performed prospectively.RESULTS:A total of 26 episodes of sAMY eruption were considered moments of SE in the H-group.The baseline level of sAMY significantly increased in association with an IR of>100% at 5 min,with a significant difference(IR immediately before elevation/IR at elevation of sAMY=8.72±173/958±1391%,P<0.001).However,effective intervention decreased the elevated sAMY level immediately within only 5 min,with a significant difference(IR at sAMY elevation/immediately after intervention=958±1391/476±1031,P<0.001).The bispectral indices,systolic blood pressure and pulse rates,which were measured at the same time,remained stable throughout the ESD.Forceful endoscopic insertion or over insufflation was performed during 22 of the 26 episodes.Release of the gastric wall tension and/or the administration of analgesic medication resulted in the immediate recovery of the elevated sAMY level,independent of body movement.CONCLUSION:By detecting twice the actual sAMY based on the preoperative level,the release of the gastric wall tension or the administration of analgesic agents should be considered.

Effects of Used Battery on Key Enzyme Activity during the Germination of Wheat Seeds

[Objective] This study aimed to explore the effects of used battery lixivium on wheat germination. [Method] The wheat seeds were treated with used battery lix- ivium at different concentrations to detect the change of activities of amylase, pro- tease, pyruvate dehydrogenase （PDH） and polyphenol oxidase （PPO） during the ger- mination period. [Result] The results showed that the used battery affected enzyme activity. With the increase of concentration of used battery lixivium, trends of the changes of amylase and protease activities were not different. The activities were en- hanced at low concentrations of lixivium, while were inhibited at high concentrations. The tends of changes of pyruvate dehydrogenase （PDH） and polyphenol oxidase （PPO） activities were not consistent with that of either amylase or protease, which showed continuous downward trends with the increasing concentration of used battery lixivium. [Conclusion] This study is of great practical significance for understanding the effects of used battery lixivium on the germination of wheat seeds.

Biochemical Changes Associated with Germinating Rice Grains and Germination Improvement

To determine biochemical changes during the germination of rice grains （Oryza sativa L. subsp, indica var. Mottaikaruppan） and to improve germination rate using gibberellic acid and surfactants [sodium dodecyl sulfate （SDS） （1.0 g/L） and Triton-X-100 （1.0 mL/L）], whole rice grains soaked in distilled water for 12 h at 30℃were germinated in the dark at 30℃ for five days. The highest germination rate （77.1%） was obtained on the 5th day. An increase in the content of reducing sugars from 7.3 to 58.1 mg/g DM （dry matter） was observed from the 1st day of germination. Free amino acids and soluble protein contents increased to 3.69 and 5.29 mg/g DM, respectively on the 5^th day of germination. Total protein content decreased from 100.5 to 91.0 g/kg DM during germination. Increases in amylolytic （1.1 to 190.0 U/g DM） and proteolytic （0 to 0.12 U/g DM） activities were observed during germination. Effects of different concentrations of gibberellic acid on the germination of rice grains were evaluated and 0.1 g/L was found to promote germination. When effects of gibberellic acid （0.1 g/L） and surfactants were evaluated individually and together, higher germination rate was observed in the control experiment （grains germinated in distilled water）, whereas giberellic acid and surfactants decreased the germination rate. Therefore, the flour obtained from the grains germinated for four days using distilled water to obtain high content of soluble materials and enzyme activities can be used in preparation of bakery items.