ELE restrains empty glumes from developing into lemmas

Although there is evident homology among reproductive organs when comparing Poaceae (grass) and eudicots, the identity of grass specific organs, such as lodicules, palea, lemma, and glumes has been the subject of a vast and largely inconclusive discussion. Here we provide some direct evidence to support the idea that the empty glumes of rice (Oryza sativa) are counterparts of lemmas. We show that the development of empty glumes is regulated by ELE (elongated empty glume), which belongs to a plant ...     

Properties of NADP-malic enzyme from glumes of developing wheat grains

Properties of partially purified NADP-malic enzyme (EC 1.1.1.40) from glumes of developing wheat grains were examined. The pH optimum for enzyme activity was influenced by malate and shifted from 7.3 to 7.6 when the concentration of malate was increased from 2 to 10 mM. The K_m values, at pH 7.3, for various substrates were: malate, 0.76 mM; NADP, 20 μM and Mn²⁺, 0.06 mM. The requirement of Mn²⁺ cation for enzyme activity could be partially replaced by Mg²⁺ or Co²⁺. Mn²⁺ dependent enzyme activity was inhibited by Pb²⁺, Ni²⁺, Hg²⁺, Zn²⁺, Cd²⁺, Al³⁺ and Fe³⁺. During the reaction, substrate molecules (malate and NADP) reacted with enzyme sequentially. Activity of malic enzyme was inhibited by products of the reaction viz pyruvate, HCO₃^? and NADPH₂. At a limiting fixed concentration of NADP, these products induced a positive cooperative response to increasing concentrations of malate.     

High-loading oil palm empty fruit bunch saccharification using cellulases from Trichoderma koningii MF6

Strain Trichoderma koningii D-64 was improved for enhanced cellulase production. A potential mutant MF6 was obtained and its enzymes contained filter paper cellulase (FPase), carboxymethylcellulase (CMCase), β-glucosidase and xylanase with respective activities of 2.0, 1.3, 2.0 and 3.0 folds of those for the parental strain. MF6 cellulases showed enhanced hydrolysis performance for the treated lignocellulosic biomass. Hydrolysis of treated oil palm empty fruit bunch (OPEFB), horticulture wastes (HW) and wood chips (WC) resulted in cellulose to glucose conversion of 96.3 ± 2.2%, 98.2 ± 3.0% and 81.9 ± 1.4%, respectively. The corresponding conversions of xylan to xylose were 96.9 ± 1.5%, 95.0 ± 2.2% and 76.1 ± 3.1%. Consistently, high sugar yield of 770–844 mg/g biomass was obtained for high-loading (10–16%, w/v) of OPEFB hydrolysis and sugar titer of 135.1 g/L was obtained for 16% (w/v) OPEFB loading at 96 h. In addition, MF6 enzymes alone performed equally well for high-loading OPEFB hydrolysis compared to the enzyme mixture of β-glucosidase from Aspergillus niger and cellulase from T. reesei Rut C30.     

Impact of amino acid and CP restriction from 20 to 140 kg BW on performance and dynamics in empty body protein and lipid deposition of entire male,castrated and female pigs

Breeding leaner pigs during the last decades may have changed pig’s empty body (EB) composition, a key trait for elaborating feeding recommendations. This research aimed to provide new experimental data on changes in the chemical composition of the EB of pigs from 20 to 140 kg BW. In addition, the impact of a reduction in the dietary CP associated with lower lysine, methionine+cystine, threonine and tryptophan levels was determined. In total, 48 males, castrates and females weighing 20 kg BW were allocated either to a control grower–finisher diet formulated according to current Swiss feeding recommendations, or a low CP grower–finisher diet (80% of control). Feed intake was monitored and pigs were weighed weekly. The chemical composition of EB (blood, hairs and hoofs, offals, bile, carcass) was determined at 20, 40, 60, 80, 100, 120 and 140 kg BW on four pigs per gender and diet (eight pigs per gender at 20 kg). The five fractions were weighed and samples were analysed for dry matter, protein, fat and energy. Nutrient deposition rates and N efficiency were calculated by using the 20 kg BW category as reference. Analysis revealed an accurate feed optimisation for the aforementioned essential amino acids (EAA), whereas digestible isoleucine content in the low CP diet was at 70% of the control diet. Despite similar feed intake, daily gain and feed efficiency were impaired (P<0.01) from 20 to 100 kg BW in the low CP compared with the control pigs. In the same growth period, castrates had the greatest feed intake but, together with females, displayed the lowest (P<0.01) feed efficiency. Protein deposition was reduced (P<0.01) by up to 31% with low CP diet and was lower (P<0.01) in castrates and females than males at 100 kg BW. The greatest fat deposition rates were found with low CP diet and castrates. N efficiency improved (P<0.05) by 10% with the low CP diet from 100 to 140 kg. The males displayed the greatest (P<0.05) N efficiency. These findings suggest that the CP content of finisher II diets could be reduced to 102, 102 and 104 g/kg for females, castrates and males, respectively, without a negative impact on protein deposition or growth. It remains unclear whether the negative effects found in the BW range from 20 to 100 kg on the EB deposition were due to the 20% reduction of the dietary CP and the five limiting EAA or to other EAA via an unbalanced EAA profile.     

A review about nothing: Are apolar cavities in proteins really empty?

Cavities within proteins that are strictly apolar typically appear to be empty. It has been suggested, however, that water molecules may be present within such cavities but are too disordered to be seen in conventional crystallographic analyses. In contrast, it is argued here that solvent mobility will be limited by the size of the cavity and for this reason high‐occupancy solvent in cavities of typical volume should be readily detectable using X‐ray crystallography. Recent experimental studies of cavity hydration are reviewed. Such studies are consistent with theoretical predictions that it is energetically unfavorable to have a single water molecule in an apolar cavity. As apolar cavities become larger, a point is reached where it is favorable to have the cavity occupied by a cluster of mutually H‐bonded water molecules. The exact size of such a cavity in a protein is yet to be verified.     

Improvement of production of citric acid from oil palm empty fruit bunches: Optimization of media by statistical experimental designs

A sequential optimization based on statistical design and one-factor-at-a-time (OFAT) method was employed to optimize the media constituents for the improvement of citric acid production from oil palm empty fruit bunches (EFB) through solid state bioconversion using Aspergillus niger IBO-103MNB. The results obtained from the Plackett–Burman design indicated that the co-substrate (sucrose), stimulator (methanol) and minerals (Zn, Cu, Mn and Mg) were found to be the major factors for further optimization. Based on the OFAT method, the selected medium constituents and inoculum concentration were optimized by the central composite design (CCD) under the response surface methodology (RSM). The statistical analysis showed that the optimum media containing 6.4% (w/w) of sucrose, 9% (v/w) of minerals and 15.5% (v/w) of inoculum gave the maximum production of citric acid (337.94 g/kg of dry EFB). The analysis showed that sucrose (p < 0.0011) and mineral solution (p < 0.0061) were more significant compared to inoculum concentration (p < 0.0127) for the citric acid production.     

Properties of glutelin from mature and developing rice grain

Aminograms and SDS-polyacrylamide electrophoresis of milled rice glutelin of 12 Oryza sativa samples showed similar composition and ratio of 1 : 1 : 1 for subunits with MW 38 000:25 000: 16 000, indicating little possibility of finding variants of rice glutelins. Fractionation of S-cyanoethyl glutelin of 3 rices on polyacrylamide-agarose gels gave MW subunits differing in amino acid analysis of which the subunits with MW > 38 000 had the highest lysine content. Of the solubility fractions of endosperm glutelin, the fraction extracted by 0.5 M NaCl-0.6 % β-mercapto-ethanol-0.5% SDS was closest to glutelin in properties. In the developing grain of two varieties, appearance of protein bodies and rapid synthesis of glutelin from 7 days after flowering onward coincided with a drop in lysine content and appearance of MW 38 000 and 25 000 of crude glutelin. The MW 38 000 subunit is thus unique to endo-sperm glutelin.     

Turgor-sensitive sucrose and amino acid transport into developing seeds of Pisum sativum. Effect of a high sucrose or mannitol concentration in experiments with empty ovules

Sugar and amino acid transport into empty ovules of Pisum sativum L. cv. Marzia was examined. In fruits containing 4–6 developing seeds, the embryo was removed from four ovules. After this surgical treatment, each empty seed coat was filled with a solution (pH 5.5) containing a low (0, 50 or 200 m M ), medium (350, 400 or 500 m M ) or high (0.7 or 1 M ) concentration of sucrose and/or mannitol. In pulse-labelling experiments with sucrose and α-aminoisobutyric acid (AIB), transport of sucrose and AIB into an empty ovule filled with a solution containing a high sucrose concentration was the same as transport into an ovule filled with a mannitol solution of similar osmolarity, demonstrating that a high sucrose concentration in the seed coat apoplast affects phloem transport of sucrose and AIB into the seed coat only by the osmotic effect. The osmolarity of a given solution filling the seed coat cavity appeared to be important for phloem transport of sucrose and AIB into empty ovules.
In our experiments, 350 m M appeared to be the optimal concentration for sucrose and AIB transport into the cavity within an empty ovule, giving results comparable with transport into intact ovules. A lower osmolarity of the solution induced less transport. Very high sucrose or mannitol concentrations caused a strong inhibition of sucrose and AIB unloading from the seed coat, so that transport into the empty ovules was inhibited. A low (strongly negative) but not too low osmotic potential of the solution in the seed coat apoplast seems necessary to maintain a normal rate of phloem transport into developing seeds. Apparently, the "sink strength" of developing seeds is turgor-sensitive.     

Purification of two forms of starch branching enzyme (Q-enzyme) from developing rice endosperm

Two isoforms of starch branching enzyme (Q-enzyme), QEI and QEII, have been purified to honlogeneity from developing rice endosperm. QEI and QEII, with molecular weights of about 80 and 85 kDa, respectively, could be fully separated by anion-exchange or hydrophobic chromatography. The peptide maps obtained after V₈ proteinase digestion were quite different between the two enzymes. Antibodies prepared against QEI showed no immunological cross-reaction with the QEII protein in Western blot experiments, and anti-QEII serum did not react with the QEI protein. The data indicate that QEI and QEII are distinct proteins encoded by different genes in rice plants.     

Analysis of randomly isolated cDNAs from developing endosperm of rice (Oryza sativa L.): evaluation of expressed sequence tags,and expression levels of mRNAs

Using a cDNA library prepared from poly(A)⁺ RNA from 10-day-old rice endosperm, partial nucleotide sequences of randomly isolated clones were analyzed. A total of 153 (30.6%) out of 500 cDNA clones showed high amino acid identity to previously identified genes. There was significant redundancy in cDNAs encoding prolamine and glutelin. About 21.0% of the cDNA clones were found to code for seed storage protein genes. Consequently, 37 independent genes were identified. Using cDNA clones encoding glutelin, prolamine, seed allergen, -1,4-glucan branching enzyme, glycine-rich RNA binding protein, metallothionein, non-specific lipid-transfer protein and ubiquitin conjugating enzyme the accumulation of mRNA during rice seed development was compared. Genes associated with seed storage protein and starch biosynthesis were expressed according to expected developmental stages. Glycinerich RNA binding protein genes as well as metallothionein-like protein genes were highly expressed in developing seeds, but low in leaves of whole plants.     

Possible migration of imaginal myoblasts from adjacent nerve sheath into the developing flight muscle of Chironomus

The emplacement of the first imaginal myoblasts along the larval muscles which are precursors of the dorsal longitudinal flight muscles, has been studied in Chironomus (Diptera, Nematocera), by light and electron microscopy. At the beginning of larval life there are no imaginal myoblasts stored along these muscles. These cells are discerned only at the beginning of the last larval instar. They first appear in the median region of the muscles near the neuromuscular junction. Prior to this, however, there are cells possessing the same cytological characteristics as the imaginal myoblasts inside the sheath of the motor nerves that supply the muscles. These observations suggest that myoblasts could arrive by the nerve sheath. The presence of a thick, continuous basal lamina around the larval muscles seems to exclude all other possibility of access to these muscles. The extension of this hypothesis to the Cyclorrhaphan Diptera is discussed.     

Adult human CD133/1 kidney cells isolated from papilla integrate into developing kidney tubules

Approximately 60,000 patients in the United States are waiting for a kidney transplant due to genetic, immunologic and environmentally caused kidney failure. Adult human renal stem cells could offer opportunities for autologous transplant and repair of damaged organs. Current data suggest that there are multiple progenitor types in the kidney with distinct localizations. In the present study, we characterize cells derived from human kidney papilla and show their capacity for tubulogenesis. In situ, nestin⁺ and CD133/1⁺ cells were found extensively intercalated between tubular epithelia in the loops of Henle of renal papilla, but not of the cortex. Populations of primary cells from the renal cortex and renal papilla were isolated by enzymatic digestion from human kidneys unsuited for transplant and immuno-enriched for CD133/1⁺ cells. Isolated CD133/1⁺ papillary cells were positive for nestin, as well as several human embryonic stem cell markers (SSEA4, Nanog, SOX2, and OCT4/POU5F1) and could be triggered to adopt tubular epithelial and neuronal-like phenotypes. Isolated papillary cells exhibited morphologic plasticity upon modulation of culture conditions and inhibition of asymmetric cell division. Labeled papillary cells readily associated with cortical tubular epithelia in co-culture and 3-dimensional collagen gel cultures. Heterologous organ culture demonstrated that CD133/1⁺ progenitors from the papilla and cortex became integrated into developing kidney tubules. Tubular epithelia did not participate in tubulogenesis. Human renal papilla harbor cells with the hallmarks of adult kidney stem/progenitor cells that can be amplified and phenotypically modulated in culture while retaining the capacity to form new kidney tubules. This article is part of a Special Issue entitled: Polycystic Kidney Disease.     

Translocation and incorporation of 14C into the petiole from different regions within developing cottonwood leaves

Summary The ability of a developing cottonwood (Populus deltoides Bartr.) leaf to export ¹⁴C-labeled assimilates begins at the lamina tip and progresses basipetally with increasing LPI. This progression indicates that portions of leaves function quasi-independently in their ability to export ¹⁴C-photosynthate. Although most of the exported radioactivity was recovered in the petiole as water-80% alcohol-soluble compounds, there was also substantial incorporation into the chloroform and insoluble fractions. This observation indicates that assimilates translocated from the lamina are used in structural development of the petiole. Freeze substitution and epoxy embedding were used to prepare microautoradiographs for localization of water-soluble compounds. Radioactivity was found in all cell types within specific subsidiary bundles of the petiole. However, radioactive assimilates appeared to move from the translocation pathway in the phloem toward active sinks in the walls of the expanding metaxylem cells. Translocation in the mature xylem vessels was not observed.     

Opinions of researchers based in the UK on recruiting subjects from developing countries into randomized controlled trials

Background: Explaining technical terms in consent forms prior to seeking informed consent to recruit into trials can be challenging in developing countries, and more so when the studies are randomized controlled trials. This study was carried out to examine the opinions of researchers on ways of dealing with these challenges in developing countries. Methods: Recorded in‐depth interviews with 12 lecturers and five doctoral students, who had carried out research in developing countries, at a leading school of public health in the United Kingdom. A purposive, snowballing approach was used to identify interviewees. Results: Researchers were divided on the feasibility of explaining technical trials in illiterate populations; the majority of them held the view that local analogies could be used to explain these technical terms. Others were of the opinion that this could not be done since it was too difficult to explain technical trials, such as randomized controlled trials, even to people in developed countries. Conclusion: Researchers acknowledged the difficulty in explaining randomized controlled trials but it was also their perception that this was an important part of the ethics of the work of scientific research involving human subjects. These difficulties notwithstanding, efforts should be made to ensure that subjects have sufficient understanding to consent, taking into account the fact that peculiar situations in developing countries might compound this difficulty.     

湿地稻-鸭复合系统中水稻纹枯病的变化规律

为了探明稻田养鸭对水稻纹枯病的发生、发展的影响 ,为稻 -鸭复合系统中水稻纹枯病的防治提供依据 ,笔者在中稻、晚稻田进行了稻田养鸭试验。试验结果表明 ,在中稻田每 6 6 6 .7m2 放养体重 15 0 g左右鸭子 15～ 2 0只 ,能使纹枯病病蔸率减少5 6 .0 % ,病株率减少 5 7.74 % ,同时比用井岗霉素防治的小区病蔸率下降 9.0 % ,病株率下降 15 .2 5 % ,病情指数比空白对照下降2 6 .4 6 ,比施用井岗霉素的施药区减少 0 .95 ;防治效果显著 ,基本可控制纹枯病的危害     

Kinetic analysis of taurine influx into cerebral cortical slices from adult and developing mice in different incubation conditions

The influx of taurine into cerebral cortical slices was studied with 3-day-old and 3-month-old mice in different ionic environments in incubation medium. In standard Krebs-Ringer medium the influx comprised two saturable uptake components, high- and low-affinity, and non-saturable penetration. In isoosmotic medium potassium stimulation abolished the high-affinity uptake in both age groups. In hyperosmotic medium the high-affinity uptake disappeared totally in 3-day-old mice and partially in 3-month-old mice. The high-affinity uptake was also obliterated in hypoosmotic medium and in the absence of chloride ions in both age groups. The low-affinity uptake was abolished by potassium stimulation in 3-month-olds and strongly inhibited in 3-day-olds. Hypoosmotic and chloride-free media also inhibited the low-affinity uptake at both ages. Non-saturable influx was greatly diminished in chloride-free media. The taurine uptake systems are thus strongly inhibited in incubation conditions which simultaneously evoke apparent release of taurine from cerebral cortical slices. This inhibition contributes to the magnitude of the estimated release, which in vitro represents overflow of released taurine molecules which escape recapture by the membrane carriers. In vivo the same mechanism may underlie the delayed and spreading neuromodulatory actions of taurine. Special issue dedicated to Dr. Kinya Kuriyama.     

Differential protein insertion into developing photosynthetic membrane Regions of Rhodopseudomonas sphaeroides

Previous studies have suggested that much of the B800-850 light-harvesting bacteriochlorophyll a-protein complex is inserted directly into the intracytoplasmic photosynthetic membrane of Rhodopseudomonas sphaeroides. In contrast, the B875 light-harvesting and reaction center complexes are assembled preferentially at peripheral sites of photosynthetic membrane growth initiation. The basis for this apparent site-specific polypeptide insertion was examined during the inhibition of RNA and protein syntheses. The pulse labeling of polypeptides at the membrane growth initiation sites was significantly less sensitive to inhibition by rifampicin, chloramphenicol, or kasugamycin than in the intfacytoplasmic or outer membranes. This suggests increased stability for the translation machinery at these membrane invagination sites. Similar differential effects in polypeptide insertion were observed during inhibition of bacteriochlorophyll synthesis through deprival of δ-aminolevulinate to R sphaeroides mutant H-5, which requires this porphyrin precursor. The pulse-labeling patterns observed during the inhibition of both RNA and pigment syntheses were consistent with the uncoupling of polypeptide insertion into the membrane invagination sites from their growth and maturation into intracytoplasmic membranes.     

Regularly aligned mitochondria in aleurone and sub-aleurone layers of developing rice caryopses

Abstract. Mitochondria were found to be aligned along the upper periclinal walls of aleurone and endosperm cells in developing rice caryopses. The significance of this distribution is discussed in relation to previous studies of solute transport in rice.     

水稻抗稻瘟病天然免疫机制及抗病育种新策略

稻瘟病是水稻最严重的病害之一,由子囊菌(Magnaporthe oryzae)引起。利用抗病品种是防治稻瘟病最经济、最有效的措施。近年来,稻瘟病已发展为研究植物与病原真菌分子互作机制的模式系统,在水稻与稻瘟菌互作和寄主抗性分子生物学、基因组学和蛋白组学等领域取得了一系列重要的研究成果。文章综述了近年来水稻抗稻瘟病两种天然免疫机制,即病原菌相关分子模式诱导和效应蛋白诱导的抗病机制研究的最新进展,讨论了GWAS、TALLEN、CRISPR和HIGS等基因组研究新方法和新技术在水稻抗病育种中的应用,并对目前稻瘟病抗性机制研究和抗病育种中的问题和挑战进行了探讨和展望。     

A transporter for delivering zinc to the developing tiller bud and panicle in rice

Tiller number is one of the most important agronomic traits that determine rice (Oryza sativa) yield. Active growth of tiller bud (TB) requires high amount of mineral nutrients; however, the mechanism underlying the distribution of mineral nutrients to TB with low transpiration is unknown. Here, we found that the distribution of Zn to TB is mediated by OsZIP4, one of the ZIP (ZRT, IRT-like protein) family members. The expression of OsZIP4 was highly detected in TB and nodes, and was induced by Zn deficiency. Immunostaining analysis revealed that OsZIP4 was mainly expressed in phloem of diffuse vascular bundles in the nodes and the axillary meristem. The mutation of OsZIP4 did not affect the total Zn uptake, but altered Zn distribution; less Zn was delivered to TB and new leaf, but more Zn was retained in the basal stems at the vegetative growth stage. Bioimaging analysis showed that the mutant aberrantly accumulated Zn in enlarged and transit vascular bundles of the basal node, whereas in wild-type high accumulation of Zn was observed in the meristem part. At the reproductive stage, mutation of OsZIP4 resulted in delayed panicle development, which is associated with decreased Zn distribution to the panicles. Collectively, OsZIP4 is involved in transporting Zn to the phloem of diffuse vascular bundles in the nodes for subsequent distribution to TBs and other developing tissues. It also plays a role in transporting Zn to meristem cells in the TBs.