RAPD and seed coat morphology variation in annual and perennial species of the genus Cicer L.

Molecular and morphological variation of six perennial and five annual species including domesticated chickpea, C. arietinum, were inferred on the basis of RAPD and S.E.M. seed coat features using three outgroup taxa (Lens ervoides, Lathyrus japonica and Pisum sativum). Of the 66 decamer arbitrary primers tested, eight primers revealed 87 informative fragments. Neighbor-joining cluster analysis using Jaccard's coefficient of similarity on the basis of polymorphic fragments indicated a narrow variation in C. arietinum and recognized two major clusters in the genus Cicer. The first one included four species of sect. Monocicer: C. echinospermum, C. arietinum, C. reticulatum and Iranian material of C. bijugum. The second cluster contained annual and perennial species belonging to sections Chamaecicer, Polycicer and Acanthocicer. The character state of morphological and ecological traits on the RAPD phenogram indicated no monophyletic incision. Our results suggested that the high genetic difference between annual and perennial species might be regarded as a rapid speciation of section Monocicer. Reconsideration of traditional classification of sections Polycicer and Acanthocicer is necessary. The Desi and Kabuli types of C. arietinum could not be separately grouped at the DNA level, and the low level of genetic variation of C. arietinum may result from a bottleneck during the domestication process.     

Effect of salinity on growth and accumulation of organic and inorganic solutes in the leguminous plants Alhagi pseudoalhagi and Vigna radiata

The response of two leguminous plants Alhagi pseudoalhagi and Vigna radiata to seawater salinity was studied over a period of 30 d. The growth of Vigna radiata was markedly and gradually reduced by increasing salinity levels, whereas that of Alhagi pseudoalhagi was promoted at 9.1 and 16.2 dS m^-1 salinity but then was slightly reduced at 28.2 dS m^-1 salinity. These results indicate that Alhagi pseudoalhagi belongs to the group of halophytic plants. Seawater salinity caused changes in the membrane permeability measured as electrolyte leakage in both plants. Alhagi pseudoalhagi maintained a lower membrane permeability than Vigna radiata. With increasing salinity levels, the membrane permeability decreased in Alhagi pseudoalhagi, whereas, in Vigna radiata it slightly increased at 9.1 dS m^-1. The leaf water potential and the osmotic potential decreased in both plants along with the seawater salinity levels. However, the turgor potential and osmotic adjustment in Alhagi pseudoalhagi were maintained at a higher level than in Vigna radiata. The contributions of organic and inorganic solutes to the osmotic adjustment differed: Alhagi pseudoalhagi achieved osmotic adjustment through Cl^- and Na⁺ uptake from the substrate, while the contribution of K⁺, Ca²⁺, and organic solutes to the osmotic adjustment was limited. These results suggest that the differences in salt tolerance between Alhagi pseudoalhagi and Vigna radiata can not be due to differences in specific-ion effects, but may be related to some factors involved in membrane permeability and osmotic adjustment.     

Effect of soil microorganisms on the growth of roots in rice seedlings

Abstract

Root system of rice seedlings grown on nutrient solution inoculated with soil microorganisms were examined morphologically in comparison with those obtained under sterile condition. In the presence of soil microorganisms, primary roots increased in their number and decreased in the total length. Inoculated plants had more secondary roots equipped with tertiary roots. In addition, longer root hairs developed densely on primary and secondary roots of the inoculated seedlings.

Anatomical examination of the primary roots revealed that the number and width of cortical layers, as well as the length and width of the cortical cells, were increased by the effect of microorganisms. Microbial effect on outer morphology of rice roots, consequently, was estimated to have been induced from the alteration in histological and cytological activities including the activation of the periclinal divisions of the epidermal cells, the inactivation of the transverse divisions of the cortical cells and the activation of the elongation of cortical cells.     

Changes in mineral concentrations in amberjack Seriola dumerili larvae during seed production: high concentrations of certain minerals in rotifers do not directly affect the mineral concentrations in larvae

This study examined the changes in mineral concentrations in amberjack Seriola dumerili larvae during seed production taking into consideration the mineral concentrations of rotifers in the larval rearing tanks (tank rotifers), since the concentrations of certain minerals in tank rotifers have been reported to be very high. In the present study, the concentrations of Ca, Mg, Fe, Zn and Mn in tank rotifers were generally higher than in freshly enriched rotifers. The extent of the increase in tank rotifers varied depending on the mineral, larval production facility and larval production trial. Concentrations of Ca in the larvae increased as they grew, those of P and Mn increased up to ca. 30 days post-hatching (DPH), those of Mg and Fe increased up to ca. 20 DPH and then decreased, and those of Zn continuously decreased through the seed production periods (to ca. 40 DPH). However, there were no clear relationships between the mineral concentrations of the tank rotifers and the larvae. These results indicate that high concentrations of minerals in tank rotifers are not directly reflected in amberjack larvae. This suggests that amberjack larvae maintain their mineral status by controlling the uptake and/or excretion of food minerals.     

A step forward in development of fish protein hydrolysate-based diets for larvae of Japanese eel Anguilla japonica

Eggs of spiny dogfish Squalus acanthias are an indispensable and effective component of the compound diets currently used for larvae of the Japanese eel Anguilla japonica. However, this fish species, a natural resource, is becoming more scarce, suggesting that suitable diets should be developed using more sustainable components. In the search for appropriate diets without shark eggs, we have designed test diets in which shark eggs were replaced with general feed materials, such as fish protein hydrolysate (FPH), with the notable improvement that the FPH had been pre-digested with integral enzymes from frozen krill. Feeding trials were conducted to assess the effects of the test diets on survival and growth of Japanese eel larvae at early developmental stages. Larvae fed on the test diets were found to be able to survive up to 65 days after hatching, the maximum total length and body depth were 14.1 and 1.5 mm, respectively. Although larvae fed on the test diets still exhibited a low survival rate and poor growth, the FPH-based diets had a nutritional value that promoted substantial larval growth based on the significant difference between the initial and final body sizes. Our results suggest that the development of FPH-based diets not based on shark eggs but rather on general feed ingredients is promising but that there is much room for improvement.     

Hot water treatment of Japanese pear trees is effective against white root rot caused by <Emphasis Type="Italic">Rosellinia necatrix</Emphasis> Prillieux

Hot water was dripped into the rhizosphere of Japanese pear trees (Pyrus serotina Rehd. grafted on P. betulifolia Bunge.) infested with the white root rot fungus Rosellinia necatrix Prillieux, to destroy the fungus. Isolates of R. necatrix from diseased roots of Japanese pear were vulnerable to water at temperatures above 35°C, and the fungus was eradicated from the colonized substrate when water at 35°C was provided for 3 days. The time required to eradicate R. necatrix decreased exponentially with increasing temperature. Japanese pear trees tolerated a temperature of 45°C without reduction in vigor. Field experiments demonstrated the practical use of hot water drip irrigation (HWD). HWD at 50°C completely destroyed white root rot mycelia on diseased roots, and many rootlets grew after the treatment. HWD at this temperature caused no injury to the trees. HWD of diseased orchard trees was assessed in Takamori and Iida in southern Nagano, Japan. The fungus recurred in two of four trees 28 months after treatment in Takamori and in two of ten trees 16 months after treatment in Iida. The new mycelia emerged on thick roots deep within the soil. Although there is a possibility of recurrence, HWD treatment is a practical control measure for white root rot.     

Influence of dietary soy protein and peptide products on bile acid status and distal intestinal morphology of rainbow trout Oncorhynchus mykiss

To investigate the influence of dietary soy protein size on the bile acid status and the distal intestinal morphology in rainbow trout Oncorhynchus mykiss, diets based on soybean meal (SBM), soy protein isolate (SPI) and 4 soy peptide products having different molecular sizes were fed to trout (initial BW, 19?g) for 10?weeks. A diet based on fish meal (Cont) and a diet including the smallest-peptide and low-saponin product (Hi-Nute AM) and supplemented with soya saponin (AMS) were also fed. In fish fed diets SBM and SPI, the gallbladder was atrophied, the proportion of biliary cholyltaurine decreased, and highly vacuolated epithelial cells of mucosal folds and proliferation of connective tissues in the submucosa of the distal intestine were observed. These parameters tended to improve in fish fed soy peptide diets and especially those of fish fed diet AM were similar to fish fed diet Cont. Although the gallbladder of fish fed diet AMS was smaller than fish fed the unsupplemented diet AM, no morphological abnormalities were observed in the distal intestine. These results suggest that soy proteins/peptides with relatively large sizes and with soya saponin affect the bile acid status and distal intestinal morphology of rainbow trout.     

Fractionation of metal complexes with dissolved organic matter in a rhizosphere soil solution of a humus-rich Andosol using size exclusion chromatography with inductively coupled plasma-mass spectrometry

To better understand the behavior of metals in soil–plant systems, their physicochemical forms in rhizosphere soil should be elucidated. The dissolved organic matter (DOM) in a soil solution influences the mobility and bioavailability of metals in soil. The present study examined the effects of plant growth on DOM–metal complexes in a rhizosphere soil solution using size exclusion chromatography combined with an inductively coupled plasma-mass spectrometer system (SEC–ICP-MS) and an ultrafiltration technique. Humus-rich volcanic ash soil from the surface of an agricultural field was used in a pot cultivation experiment. Brassica rapa nothovar. was cultivated in a pot in which rhizosphere soil (R) was separated by a nylon net screen from non-rhizosphere soil (NR). Soil solutions were collected using a high-speed centrifugation method 3 weeks after sowing and analyzed using SEC–ICP-MS. Some peaks of DOM with a high molecular size were detected in the ultraviolet-absorbing chromatograph (280 nm) of the soil solution samples. Their concentrations were much higher in the R solution than in the NR solution. Metals including Al, Fe, Cu, Zn, Pb, Y, La and U were detected at the ultraviolet peak positions of the DOM. The ultrafiltration experiment showed that the size distributions of the organic materials to which the metals were combined differed between the R and NR soil solutions. These results suggest that plant growth enhanced the dissolution of metals adsorbed with organic matter from the solid phase in rhizosphere soil.     

Robust reconstitution of active cell-cycle control complexes from co-expressed proteins in bacteria

ABSTRACT: BACKGROUND: Cell proliferation is an important determinant of plant growth and development. In addition,modulation of cell-division rate is an important mechanism of plant plasticity and is key inadapting of plants to environmental conditions. One of the greatest challenges inunderstanding the cell cycle of flowering plants is the large families of CDKs and cyclins thathave the potential to form many different complexes. However, it is largely unclear whichcomplexes are active. In addition, there are many CDK- and cyclin-related proteins whosebiological role is still unclear, i.e. whether they have indeed enzymatic activity. Thus, abiochemical characterization of these proteins is of key importance for the understanding oftheir function. RESULTS: Here we present a straightforward system to systematically express and purify active CDKcyclincomplexes from E. coli extracts. Our method relies on the concomitant production of aCDK activating kinase, which catalyzes the T-loop phosphorylation necessary for kinaseactivity. Taking the examples of the G1-phase cyclin CYCLIN D3;1 (CYCD3;1), the mitoticcyclin CYCLIN B1;2 (CYCB1;2) and the atypical meiotic cyclin SOLO DANCERS (SDS) inconjunction with A-, B1- and B2-type CDKs, we show that different CDKs can interact withvarious cyclins in vitro but only a few specific complexes have high levels of kinase activity. CONCLUSIONS: Our work shows that both the cyclin as well as the CDK partner contribute to substratespecificity in plants. These findings refine the interaction networks in cell-cycle control andpinpoint to particular complexes for modulating cell proliferation activity in breeding.     

Simultaneous detection of benzimidazole-resistant strains of Fusarium head blight using the loop-mediated isothermal amplification-fluorescent loop primer method

The loop-mediated isothermal amplification (LAMP)-fluorescent loop primer (FLP) method detects genetic polymorphisms by using a LAMP amplicon and measuring the peak temperatures of fluorescence resonance energy transfer between an FLP and a quencher probe, which is specifically hybridized to a sequence including a single nucleotide polymorphism (SNP). In the present study, the LAMP-FLP method was used to detect mutant genotypes F167Y, E198Q, and F200Y in the β2-tubulin gene region of causal pathogens of Fusarium head blight of wheat that result in methyl benzimidazole carbamate (MBC) resistance, proving its usefulness for monitoring strains with SNPs in target regions of MBC resistance.