Calcium translocation and accumulation into potato tubers

Summary Calcium uptake into potato plants was examined using test solutions containing 5% safranin dye (C₂₀H₁₉N₄C1 mw 350.85) and the radiotracer⁴⁵CaCl₂. When minitubers were suspended in test solutions for up to 5 days, safranin moved into the outer pith tissues while⁴⁵Ca²⁺ was located throughout the pith. Ca²⁺ is apparently taken up directly from the tubersphere by a slow diffusion process. Plantlets with one microtuber were used to investigate calcium uptake via basal roots.⁴⁵Ca²⁺ was well ahead of the safranin dye front in all plantlet stems.⁴⁵Ca²⁺ in shoot tips was significantly greater than in microtubers and no safranin entered the microtubers. Greenhouse-grown ex vitro plantlets with minitubers attached were used to determine the relative uptake by basal and stolon roots. Basal root feeding contributed significantly more⁴⁵Ca²⁺ to shoot tips and tubers than stolon root feeding while combined feeding gave the greatest shoot tip and tuber⁴⁵Ca²⁺ levels.     

海栖热袍菌极端耐热木聚糖酶B的提纯

克隆并在大肠杆菌中表达的海栖热袍菌的 xyn B基因 ,其表达产物木聚糖酶 B的 C 末端带有 6×His标签 ,研究了这种基因重组酶的提纯方法。通过对粗酶提取液的热变性处理 ,Ni NTA亲和柱层析和离子柱层析 ,最终得到了电泳纯的木聚糖酶 B,提纯倍数 4 4.4 ,得率 11。SDS PAGE法测定木聚糖酶 B的相对分子质量为 4 2 ku,与理论推算值 4 2 333u相吻合     

Impact of in-field soil heterogeneity on biomass and yield of winter triticale in an intensively cropped hummocky landscape under temperate climate conditions

Precision Agriculture - Crop cultivation provides ecosystem services on increasingly large fields. However, the effects of in-field spatial heterogeneity on crop yields, in particular triticale,...     

Annually twice induced spawnings provide multiple benefits: Experimental evidence from an Indian major carp (Catla catla,Hamilton 1822)

Multiple spawnings are special reproductive tactics that many fish evolved to obtain different types of direct and/or indirect spawning benefits. This has led to two pertinent questions: (a) what types of benefit does a commercially important fish provide during multiple induced spawnings annually? and (b) is there any trade‐off between traits during these spawnings? To address these questions, the present study was carried out with two separate experiments during two spawning events of an Indian major carp (Catla catla) to assess: (a) male's spawning performances and (b) female's spawning performances. The male's spawning data revealed that they produced significantly higher amount of milt and hatchlings during the first spawning, while they significantly reduced hatchling deformation rate, enhanced offspring survival rate and enlarged offspring body size during the second spawning. The female's spawning information unveiled no significant differences in total egg weight, hatching rate and hatchling deformation rate between the first and second spawning. However, females had significantly higher offspring survival rate during the first spawning and enhanced offspring body size during the second spawning. Interestingly, the analysis of trait associations revealed that males allocated energy with a trade‐off between milt weight and offspring survival rate, whereas females showed a trade‐off between hatching rate and offspring survival rate. Thus, the study provides some important information for carp breeders and associated stakeholders to know which spawning season is preferable for the higher production of eggs, milt and good quality larvae.     

Purification and characterization of collagenolytic proteases from the hepatopancreas of northern shrimp (Pandalus eous)

Three gelatinolytic proteases (A1, A2, and B) were purified using a synthetic substrate, DNP-Pro-Gln-Gly-Ile-Ala-Gly-Gln-d-Arg, from the hepatopancreas of Northern shrimp (Pandalus eous) by several chromatographic steps involving hydroxyapatite column chromatography, gel filtration on Superdex75, and ion-exchange chromatography on a MonoQ column. Collagenolytic proteases A2 and B, but not protease A1, were demonstrated to digest native porcine type I collagen at 25 degrees C and pH 7.5. Further characterizations of these two collagenolytic proteases showed that the pH optimum of enzyme A2 against DNP-peptide was found to be 11, whereas that of enzyme B was 8.5. The optimum temperature ranged between 40 and 45 degrees C for both enzymes, although enzyme B appeared to be thermally more stable than enzyme A2 at pH 7.5. Both enzymes were strongly inhibited by PMSF and antipain, which suggests that they belong to collagenolytic serine proteases.     

Interactive effect of shade and PEG-induced osmotic stress on physiological responses of soybean seedlings

Intensively farmed crops used to experience numerous environmental stresses. Among these, shade and drought significantly influence the morpho-physiological and biochemical attributes of plants. However, the interactive effect of shade and drought on the growth and development of soybean under dense cropping systems has not been reported yet. This study investigated the interactive effect of PEG-induced osmotic stress and shade on soybean seedlings. The soybean cultivar viz., C-103 was subjected to PEG-induced osmotic stress from polyethylene glycol 6000(PEG-6000) under shading and non-shading conditions. PEG-induced osmotic stress significantly reduced the relative water contents, morphological parameters, carbohydrates and chlorophyll contents under both light environments. A significant increase was observed in osmoprotectants, reactive oxygen species and antioxidant enzymes in soybean seedlings. Henceforth, the findings revealed that, seedlings grown under non-shading conditions produced more malondialdehyde and hydrogen peroxide contents as compared to the shade-treated plants when subjected to PEG-induced osmotic stress. Likewise, the shaded plants accumulated more sugars and proline than non-shaded ones under drought stress. Moreover, it was found that nonshaded grown plants were more sensitive to PEG-induced osmotic stress than those exposed to shading conditions, which suggested that shade could boost the protective mechanisms against osmotic stress or at least would not exaggerate the adverse effects of PEG-induced osmotic stress in soybean seedlings.     

Effect of different densities of parthenium weed (Parthenium hysterophorus L.) on the performance of direct-seeded rice under aerobic conditions

Parthenium weed (Parthenium hysterophorus L.) is an emerging weed species in direct-seeded aerobic systems of rice production. This two-year field study was conducted to evaluate the effect of five different densities (0, 5, 10, 15 and 20 plants m^?2) of parthenium weed on rice yield and yield-related attributes. Parthenium weed produced ca. 38 to 178% higher biomass at its densities of 10 to 20 plants m^?2 as compared to the lowest density of 5 plants m^?2. The paddy yield and yield-related attributes were negatively affected with an increase in the parthenium weed density. In both years, the highest reductions in number of rice panicles (14 to 17%), panicle length (10 to 11%), number of grains per panicle (11 to 18%), 1000-grain weight (8 to 21%) and paddy yield (30 to 35%) were recorded at the highest parthenium weed density (20 plants m^?2) tested. However, the lower densities of 5 to 15 parthenium weed plants m^?2 also caused 11 to 24% and 12 to 26% losses in paddy yield during the years 2016 and 2017, respectively. Therefore, this weed species should be controlled below the density of 5 plants m^?2 to avoid the substantial yield losses (over 15%) in direct-seeded rice.