Optimization of plant regeneration system in vitro culture in wheat

Studies were carried out to establish an efficient regeneration system of three bread wheat cultivars. Results showed induction medium containing 2,4-dichlorophenoxyacetic acid (2,4-D) had a higher plantlet regeneration frequency than Piclorm, with an average frequency of 54% in all treatments. Optimal condition for different genotypic rice was as following: induction medium (MSS 3AA/2) with 0.5 mg L-1 2,4-D, regeneration medium (R) with 0.01 mg L-1 2,4-D and 3 mg L-1 KT. The average regeneration frequency reached 83.3% under the condition. Correlation analysis showed that root differentiation, in different level, correlated with green spot regeneration, and with the number of regenerated plants per callus. No correlation was found between green spots regenerated and the numbers of plants regenerated per callus.

Regeneration of 2-amino-2-methyl-1-propanol used for carbon dioxide absorption

To improve the efficiency of the carbon dioxide cycling process and to reduce the regeneration energy consumption, a sterically hindered amine of 2-amino-2-methyl-1- propranol （AMP） was investigated to determine its regeneration behavior as a CO2 absorbent. The CO2 absorption and amine regeneration characteristics were experimentally examined under various operating conditions. The regeneration efficiency increased from 86.2% to 98.3% during the temperature range of 358 to 403 K. The most suitable regeneration temperature for AMP was 383 K, in this experiment condition, and the regeneration efficiency of absorption/regeneration runs descended from 98.3% to 94.0%. A number of heat-stable salts （HSS） could cause a reduction in CO2 absorption capacity and regeneration efficiency. The results indicated that aqueous AMP was easier to regenerate with less loss of absorption capacity than other amines, such as, monoethanolamine （MEA）, diethanolamine （DEA）, diethylenetriamine （DETA）, and N-methyldiethanolamine （MDEA）.

Establishment of a Highly Efficient Regeneration System for the Mature Embryo Culture of Wheat

Establishment of a highly efficient regeneration system for the mature embryo of wheat will provide a convenient tool for wheat tissue culture and transformation, thereby facilitating the transformation of foreign genes into wheat. By using the mature embryos derived from 20 different wheat lines including Shi 4185, Yumai 66, Lunxuan 987, CB037, Yangmai 6, Xinchun 9, Bobwhite, Han 6172, Zheng 9023, Jimai 20, Ningchun 4, and Jing 411, the effects of some factors including inoculation methods, initiating culture media, organic additives, antioxidants, and auxins on the regeneration from the explants were evaluated. The results indicated that the scraping embryo culture was better than the whole embryo culture, the Aa medium was better than the SD2 medium and dicamba was better than 2,4-D in increasing the regeneration frequency. An Adi medium was established in this study by adding silver nitrate, cysteine, ascorbic acid, dicamba, glutamine into the Aa medium at the concentration of 4,40, 100, 2, and 5 mg L^-1, respectively. By using the Adi medium and the scraping technique, the regeneration frequencies of the mature embryos of CB037, Lunxuan 987, Hart 6172, Yangmai 6, Bobwhite, Zheng 9023, Shi 4 185, and Jimai 20 became 85.6, 60,1, 46.0, 42.1,42.0, 34.0, 33.0, and 32.0%, respectively, which were about 5-8 times higher than that obtained from the conventional culture mediums and techniques. This novel regeneration system could be helpful in wheat transformation.

Efficient Regeneration and Agrobacterium-mediated Transformation of Brassica napus Cultivar Qingza No.5

Using the hypocotyl and cotyledon explants of Brassica napus L. cuhivar Qingza No. 5 as receptors, hormone combinations in bud differentiation medi- um, bud growth medium and rooting medium were optimized to establish an efficient plantlet regeneration system of B. napus cuhivar Qingza No. 5. The results showed that the highest differentiation efficiency of hypocotyls of B. napus cuhivar Qingza No. 5 reached about 90%, which was three times that of cotyledons. The appropriate differentiation medium was MSB ＋ 5 mg/L thidiazuron （TDZ） ＋7.5 mg/L AgNO3 ＋ 0.1 mg/L NAA ＋ 2 mg/L proline （L-pro） ＋ 250 mg/L casein acid hydrolysate （CH） ＋ 3% sucrose; the appropriate growth medium was 1/2 MSB ＋ 1 mg/L IBA ＋ 2 mg/L L-pro ＋ 250 mg/L CH ＋ 1.5% sucrose; the ap- propriate rooting medium was 1/2 MSB ＋ 0.2 mg/L IAA ＋ 1.5% sucrose. On this basis, a binary expression vector harboring insect resistance gene B12 was constructed and introduced into B. napus hypocotyls by Agrobacterium-mediated transformation. Positive plants were screened using hygromycin and carbenicillin. Transgenic plants were verified by PCR and GUS histochemical staining. The results showed that insect resistance gene B12 was successfully integrated into the nu- clear genome of B. napus plants and could be expressed normally. Leaves of transgenic plants with high expression levels were collected for indoor inoculation test with Plutella xylotella larvae to evaluate insect resistance of transgenic plants.

An efficient culture procedure for micro-propagation of rice regeneration plants

In this paper,we describe briefly an efficientculture procedure for micro-propagation of riceregeneration plants.The procedure consists ofthe following steps: 1.Preparation of materials Calli wereinduced from mature seeds of an indica rice lineG67 by culturing the husked and disinfectedseeds on agar medium,consisting of Nbasalelements,3％ sucrose,1000mg/L proline,and 32mg/L 2,4-D.After one month＇s in- duction culture and 3 wk subculture,compactand nodular calli were picked out and trans- ferred into liquid medium for suspension cul-tures.The liquid medium contained the same

Bone tissue regeneration:The role of finely tuned pore architecture of bioactive scaffolds before clinical translation

Spatial dimension of pores and interconnection in macroporous scaffolds is of particular importance in facilitating endogenous cell migration and bone tissue ingrowth.However,it is still a challenge to widely tune structure parameters of scaffolds by conventional methods because of inevitable pore geometrical deformation and poor pore interconnectivity.Here,the long-term in vivo biological performances of nonstoichiometric bioceramic scaffolds with different pore dimensions were assessed in critical-size femoral bone defect model.The 6%Mg-substituted wollastonite(CSi-Mg6)powders were prepared via wet-chemical precipitation and the scaffolds elaborately printed by ceramic stereolithography,displaying designed constant pore strut and tailorable pore height(200,320,450,600μm),were investigated thoroughly in the bone regeneration process.Together with detailed structural stability and mechanical properties were collaboratively outlined.BothμCT and histological analyses indicated that bone tissue ingrowth was retarded in 200μm scaffolds in the whole stage(2-16 weeks)but the 320μm scaffolds showed appreciable bone tissue in the center of porous constructs at 6-10 weeks and matured bone tissue were uniformly invaded in the whole pore networks at 16 weeks.Interestingly,the neo-tissue ingrowth was facilitated in the 450μm and 600μm scaffolds after 2 weeks and higher extent of bone regeneration and remodeling at the later stage.These new findings provide critical information on how engineered porous architecture impact bone regeneration in vivo.Simultaneously,this study shows important implications for optimizing the porous scaffolds design by advanced additive manufacture technique to match the clinical translation with high performance.

Bioceramic scaffolds with triply periodic minimal surface architectures guide early-stage bone regeneration

The pore architecture of porous scaffolds is a critical factor in osteogenesis,but it is a challenge to precisely configure strut-based scaffolds because of the inevitable filament corner and pore geometry deformation.This study provides a pore architecture tailoring strategy in which a series of Mg-doped wollastonite scaffolds with fully interconnected pore networks and curved pore architectures called triply periodic minimal surfaces(TPMS),which are similar to cancellous bone,are fabricated by a digital light processing technique.The sheet-TPMS pore geometries(s-Diamond,s-Gyroid)contribute to a 3‒4-fold higher initial compressive strength and 20%-40%faster Mg-ion-release rate compared to the other-TPMS scaffolds,including Diamond,Gyroid,and the Schoen’s I-graph-Wrapped Package(IWP)in vitro.However,we found that Gyroid and Diamond pore scaffolds can significantly induce osteogenic differentiation of bone marrow mesenchymal stem cells(BMSCs).Analyses of rabbit experiments in vivo show that the regeneration of bone tissue in the sheet-TPMS pore geometry is delayed;on the other hand,Diamond and Gyroid pore scaffolds show notable neo-bone tissue in the center pore regions during the early stages(3-5 weeks)and the bone tissue uniformly fills the whole porous network after 7 weeks.Collectively,the design methods in this study provide an important perspective for optimizing the pore architecture design of bioceramic scaffolds to accelerate the rate of osteogenesis and promote the clinical translation of bioceramic scaffolds in the repair of bone defects.

Porous solid inspired hyper-crosslinked polymer liquids with highly efficient regeneration for gas purification

Separation media that combine the desired material properties within a single material for a given process remain an ongoing challenge for the gas separations in industry.Process integration of porous solid adsorbents is difficult due to their limited volumetric capacity,whereas issues of volatility and high regeneration temperatures exist for liquid amines and physical solvents.Herein,we report a family of polymer liquids inspired by hyper-crosslinked polymers(HCPs),a class of highly swellable network polymers.Compared with a chemically similar porous solid,the HCP-liquids demonstrate good volumetric capacity and improved selectivity of carbon dioxide over methane.Uptake appears to be enhanced by intramolecular swelling of the HCP-liquids at elevated pressures,while guests are strongly rejected from the HCP-liquids at slightly elevated temperatures,leading to highly efficient regeneration.Heat of adsorption and specific heat capacity of the HCP-liquids are also low,further suggesting favourable process thermodynamics.Additionally being easily prepared at scale,the presented HCP-liquids represent a promising step towards a material with the requisite properties to replace conventional scrubbing solvents to drastically reduce the footprint and energy needs of gas separations.