5-Aminolevulinic acid promotes anthocyanin accumulation in Fuji apples

5-Aminolevulinic acid (ALA) is an essential precursor of all tetrapyrrole compounds such as chlorophylls and heme in plants. It has also been suggested widely for applications to crops to enhance growth and production as a plant growth regulator. However, how successful ALA can be used in fruit production was rarely reported. We conducted a field experiment at eight locations in four provinces across eastern China; and the results showed that application of ALA solutions to ‘Fuji’ apple (Malus × domestica Borkh.) fruits 20 days prior to harvest significantly increased the anthocyanin content in the fruit skin. Also, ALA treatment increased the anthocyanin content of the detached apple skin in a growth chamber. Results from the semi-quantitive RT-PCR analysis showed that ALA induced gene expressions related to anthocyanin biosynthesis, including the structural genes Pal, Chs and Ufgt, and regulatory genes Myb, bHLH and Wd40. When levulinic acid (LA), an inhibitor of ALA dehydrase, was added, ALA promotion of anthocyanin accumulation and up-regulation of gene expressions were inhibited. Taken together, these results suggest that ALA promotion of anthocyanin accumulation in apples was facilitated by the up-regulation of gene expression, which might be related to the conversion of ALA to porphyrins.     

The impact of roads on the avifauna of páramo grasslands in Cajas National Park,Ecuador

National parks are an important tool for conserving biodiversity, particularly in areas of high biodiversity and endemism such as the tropical Andes. However, national parks often face a variety of stressors related to recreation, road construction and illegal extraction of natural resources. Unfortunately, the influence of these stressors for biodiversity is rarely well documented. Cajas National Park in Ecuador is no exception. Despite being traversed by the Cuenca-Molleturo-Naranjal road, effects of the road construction on biodiversity have not been determined. We therefore assessed the influence of road proximity on bird species richness and abundance as well as composition of bird habitat groups in Cajas National Park using transect walks at 25 m and 250 m distance to the road (overall 18 transects, each 1 km length). In total, we recorded 1110 individuals of 28 páramo bird species. Overall species richness did not differ between transects near and far from the road. Nevertheless, the average abundance of shrubby páramo species was significantly higher far from the road than near the road (Far = 36, Near = 25). Moreover, we found a tendency towards differences in the composition of bird habitat groups between transects near and far from the road. One aspect potentially driving the observed patterns was the increasing proportion of planted non-native woody tree species within páramo grassland near the road, which may have caused reduced abundances of shrubby páramo bird species there. While roads represented a clear impact on the composition of bird species in the páramo, the major effect seems to be driven by the introduction of non-native plant species along the roadside. In order to reduce the impact of roads to a minimum, we suggest that park managers should control the introduction of such plant species.     

Length‐weight relationships of flatfish species caught by bottom trawl in the Yellow Sea and the Bohai Sea,China

This study determined the length–weight relationships of five flatfish species from the Yellow Sea and the Bohai Sea in China. Two of the species (Cynoglossus semilaevis and Verasper variegatus) had no previous length‐weight estimates.     

Length–weight relationships of 43 fish species from Haizhou Bay,central Yellow Sea

Specimens of 43 fish species belonging to 25 families were collected from seasonal bottom trawl surveys in Haizhou Bay from March to December 2011. The length–weight relationships (LWRs) of these fish species were estimated, with 22 species presented for the first time. Maximum total length records of ten species exceeded those in FishBase. The effects of sex, season and growth phase on the relationships for some of these species were taken into account whereby one species had significantly (P < 0.05) different LWRs by sex, and eight species exhibited significantly different LWRs by season. Two different growth stanzas were detected for two species using the double‐logarithmic plot of body weight versus total length.     

Keratinocyte galvanotaxis in combined DC and AC electric fields supports an electromechanical transduction sensing mechanism

Sedentary keratinocytes at the edge of a skin wound migrate into the wound, guided by the generation of an endogenous electric field (EF) generated by the collapse of the transepithelial potential. The center of the wound quickly becomes more negative than the surrounding tissue and remains the cathode of the endogenous EF until the wound is completely re‐epithelialized. This endogenous guidance cue can be studied in vitro. When placed in a direct current (DC) EF of physiological strength, 100 V/m, keratinocytes migrate directionally toward the cathode in a process known as galvanotaxis. Although a number of membrane‐bound (e.g., epidermal growth factor receptor (EGFR), integrins) and cytosolic proteins (cAMP, ERK, PI3K) are known to play a role in the downstream signaling mechanisms underpinning galvanotaxis, the initial sensing mechanism for this response is not understood. To investigate the EF sensor, we studied the migration of keratinocytes in a DC EF of 100 V/m, alternating current (AC) EFs of 40 V/m at either 1.6 or 160 Hz, and combinations of DC and AC EFs. In the AC EFs alone, keratinocytes migrated randomly. The 1.6 Hz AC EF combined with the DC EF suppressed the direction of migration but had no effect on speed. In contrast, the 160 Hz AC EF combined with the DC EF did not affect the direction of migration but increased the migration speed compared to the DC EF alone. These results can be understood in terms of an electromechanical transduction model, but not an electrodiffusion/osmosis or a voltage‐gated channel model. Bioelectromagnetics 34:85–94, 2013. © 2012 Wiley Periodicals, Inc.     

Photoperiodic reaction in the beet webworm Loxostege sticticalis L. (Pyraloidea, Crambidae) from eastern and western parts of its Eurasian range

The beet webworm, Loxostege sticticalis L., is a very dangerous polyphagous insect pest whose outbreaks periodically occur in southern Russia and northern China. The aim of our work was to describe the photoperiodic response of beet webworm populations from western (Krasnodar Territory and Rostov Province) and eastern [Buryatia and China (Hebei Province)] parts of the pest range. The insects were reared under constant photoperiods of 12–18 h and constant temperatures of 19–25°C. Incidence of diapause at different photoperiods did not show any considerable geographic differences, and the critical day length at which 50% of prepupae arrested their development was about 14–15 h in all the populations studied at experimental temperatures. The results obtained agree with the hypothesis on the existence of an area (or areas) where the pest survives during adverse periods and wherefrom it spreads when an outbreak begins (Saulich et al., 1983; Goryshin et al., 1986). Presumably, the larger part of the pest native habitats (to the north of the steppe zone) is occupied by temporary populations, incapable of surviving for long periods without an inflow of migrants from more southerly steppe regions.     

A plant‐traits approach to assessing the success of alien weed species in irrigated Mediterranean orchards

In addition to their impact on natural habitats, invasive alien plants can have a significant negative effect on agricultural systems and cause economic losses. Flood‐irrigated orchards in the Mediterranean Basin are vulnerable to the invasion of alien weeds, primarily because of the traditional management practices used in the orchards, which are characterized by high soil moisture during the dry summer period, nutrient availability and high levels of disturbance. This study sought to determine whether their biological traits can explain the success of alien weed species. To answer this question, 408 floristic relevés were conducted in 136 flood‐irrigated orchards on the Plains of Lleida (Catalonia, NE of Spain). Richness and cover of native and alien weeds were compared. Furthermore, a set of biological traits were compared between successful and non‐successful weeds for the whole data and separately between native and alien weeds using logistic regression and classification trees. In flood‐irrigated orchards, alien species covered most of their area, even though the richness of alien species was lower than that of the native species. The most important species were C4 species with seeds dispersed by water, and on the other hand, rosulate and caespitose‐reptant hemicryptophytes with long flowering period. Most of these traits fitted with those of the invasive alien weeds, which were mostly C4 species with seeds dispersed by water. Perennial life form characterized successful native weeds. In this study, we discuss how the traditional management of flood irrigation in fruit‐tree orchards favours invasive alien weeds that have specific traits, acting as a reservoir for the spread of alien weeds into other crops and surrounding riparian habitats. We also propose changing management practices in order to avoid the selection of alien weeds and to promote native species.     

A high salt tolerant neutral protease from Aspergillus Oryzae: Purification, characterization and kinetic properties

A neutral high salt tolerant protease from Aspergillus oryzae CICIM F0899 which could be used for soy sauce production and other relevant applications under high-salt conditions was purified to homogeneity through ammonium sulfate precipitation, ion-exchange chromatography and gel filtration chromatography with overall recovery of 2%. Its molecular weight was estimated to be 50 kDa by SDS-PAGE. The optimum pH and temperature for activity of the extracellular protease of A. oryzae CICIM F0899 were shown to be between 7.0–9.0, and 50°C, respectively. The protease behaved high salt tolerance in 18% NaCl and retained 72% of initial activity after 14 days, indicating the high stability. The enzyme activity was inhibited by metal ions such as Al³⁺ and Ag⁺, and slightly activated by Mn²⁺ and Cu²⁺. A kinetic model incorporating the Debye-Hückel limiting law was proposed for A. oryzae CICIM F0899 protease hydrolysis of casein at ionic strength NaCl from 0.10 to 3.18 M. It was found that, with the higher ionic strength, the Michaelis constant K _m of the protease monotonically increased while the turnover number k _cat decreased in accordance with first order kinetic model. The high-salt tolerant protease has been demonstrated to be promising for the soy sauce production process.