OBJECTIVETo analyze the relationship between the net photosynthetic rate and the quality of Siraitia grosvenorii.

METHODTaken two species of S. grosvenorii: Yongqing No. 1 and Yehong No. 1 as the experimental material, CI-310 portable photosynthesis system was used to test the net photosynthetic rate in the late growth period; HPLC was used to determine momordica-glycosides V.

RESULTLight compensation point of Yongqing No. 1 was lower than that of Yehong No. 1 and the light saturation point was identical, the weight of dried fruit and the content of momordica-glycosides V of Yongqing No. 1 were higher than those of Yehong No. 1 at the late growth period.

CONCLUSIONThe net photosynthetic rate can be used as an important subservient index to assess the quality of S. grosvenorii.

Microalgae are a group of photosynthetic microorganisms, which have the general characteristics of plants such as photosynthesis, and some species have the ability of movement which resembles animals. Recently, it was reported that microalgae cells can be engineered to precisely deliver medicine-particles and other goods in microfluidic chips. These studies showed great application potential in biomedical treatment and pharmacodynamic analysis, which have become one of the current research hotspots. However, these developments have been rarely reviewed. Here, we summarized the advances in manageable movement exemplified by a model microalgae Chlamydomonas reinhardtii based on its characteristics of chemotaxis, phototaxis, and magnetotaxis. The bottlenecks and prospects in the application of microalgae-based tactic movement were also discussed. This review might be useful for rational design and modification of microalgal manageable movement to achieve targeted transport in medical and other fields.
Chlamydomonas reinhardtii ; Microalgae ; Microfluidics ; Photosynthesis

OBJECTIVETo study the relationship between photosynthetic characteristics and environmental factors in leaves of P. lobata.

METHODPhotosynthetic characteristics and environmental factors were measured by using CIRAS-2 portable photosynthesis system.

RESULTThe apparent quantum yield in leaves was 0.0173 micromol CO2 x micromol(-1) photon. The dark respiration rate was 2.9333 micromol x m(-2) x s(-1). The light compensation point of photosynthesis was 180 micromol x m(-2) x s(-1). The light saturation point was 1600 micromol x m(-2) x s(-1). The carboxylation efficiency was 0.0338 micromol x m(-2) x s(-1). The light respiration rate was 2.5 micromol x m(-2) x s(-1). The CO2 compensation point was 100 micromol x mol(-1), The CO2 saturation point was 1 600 micromol x mol(-1).

CONCLUSIONPhoto flux density and air temperature are major environmental factors influencing diumal changes of net photosynthetic rate.

Microcystis aeruginosa, a type of algal bloom microalgae, is widely distributed in water, causing serious deteriorated effects on humans and the ecological environment. As a biocontrol microorganism, Bacillus subtilis can synthesize various bioactive substances through non-ribosomal peptide synthetase, to inhibit the growth of M. aeruginosa. Thus, it is imperative to investigate the non-ribosomal peptide (NRP) metabolites of B. subtilis fmb60. Three NRP metabolites from B. subtilis fmb60 including bacillibactin, surfactin and fengycin were extracted and identified by genome mining technology. The growth inhibition of M. aeruginosa was studied by adding various concentrations of NRP metabolites. The half-effect concentration value (EC50.4 d) of M. aeruginosa was 26.5 mg/L after incubation for 4 days. With the increasing concentration, the inhibitory effects of NRP metabolites of B. subtilis fmb60 on M. aeruginosa was enhanced significantly. Compared with the control group, with the addition of 50 mg/L NRP metabolites to the M. aeruginosa, the content of Fv/Fm, Fv/Fo and Yield parameter after cultured for 4 days were decreased by 2.8%, 1.7% and 2.0%, respectively. Those findings indicate that the NRP metabolites of B. subtilis fmb60 can significantly inhibit the photosynthesis and metabolism of M. aeruginosa, which provides a theoretical foundation for the development of biological algae inhibitor of B. subtilis.
Bacillus subtilis ; Humans ; Microcystis ; Peptides ; Photosynthesis

Biorefinery technologies provide promising solutions to achieve sustainable development facing energy and environment crisis, while abundant sugar feedstock is an essential basis for biorefinery industries. Photosynthetic production of sucrose with cyanobacteria is an alternative sugar feedstock supply route with great potentials. Driven by solar energy, cyanobacteria photosynthetic cell factory could directly convert carbon dioxide and water into sucrose, and such a process could simultaneously reduce carbon emissions and supply sugar feedstocks. Here we introduced the history and updated the state-of-the-art on development of cyanobacteria cell factories for photosynthetic production of sucrose, summarized the progress and problems on mechanisms of sucrose synthesis, metabolic engineering strategies and technology expansions, and finally forecasted the future development direction in this area.
Carbon Dioxide ; Cyanobacteria ; Metabolic Engineering ; Photosynthesis ; Sucrose

The use of light energy to drive carbon dioxide (CO₂) reduction for production of chemicals is of great significance for relieving environmental pressure and solving energy crisis. Photocapture, photoelectricity conversion and CO₂ fixation are the key factors affecting the efficiency of photosynthesis, and thus also affect the efficiency of CO₂ utilization. To solve the above problems, this review systematically summarizes the construction, optimization and application of light-driven hybrid system from the perspective of combining biochemistry and metabolic engineering. We introduce the latest research progress of light-driven CO₂ reduction for biosynthesis of chemicals from three aspects: enzyme hybrid system, biological hybrid system and application of these hybrid system. In the aspect of enzyme hybrid system, many strategies were adopted such as improving enzyme catalytic activity and enhancing enzyme stability. In the aspect of biological hybrid system, many methods were used including enhancing biological light harvesting capacity, optimizing reducing power supply and improving energy regeneration. In terms of the applications, hybrid systems have been used in the production of one-carbon compounds, biofuels and biofoods. Finally, the future development direction of artificial photosynthetic system is prospected from the aspects of nanomaterials (including organic and inorganic materials) and biocatalysts (including enzymes and microorganisms).
Carbon Dioxide/metabolism* ; Photosynthesis ; Metabolic Engineering

To solve the serious problem of stem and leaf shading in the middle and late stage of traditional flat planting of Codonopsis pilosula, this study analyzed the effects of different stereoscopic traction heights on the photosynthetic characteristics and growth of C. pilosula and explored the optimal traction height to improve the yield and quality of C. pilosula. The experiment designed three stereo-scopic traction heights [H1(60 cm), H2(90 cm), and H3(120 cm)] with natural growth without traction as the control(CK). The results showed that the increase in stereoscopic traction heights broadened the growth space of stems and leaves of C. pilosula, enhanced the ventilation effect, significantly increased the average daily net photosynthetic rate of C. pilosula, promoted the absorption of intercellular CO_2, decreased the transpiration rate, and reduced the evaporation of water. Moreover, it effectively avoided the problem of weakened photosynthesis, maintained the carbon balance of individual plants, and promoted the growth and development of the C. pilosula roots. In terms of the seed yield of C. pilosula, it was ranked as H2>H1>H3>CK. To be specific, H1 increased by 213.41% compared with CK, H2 increased by 282.43% compared with CK, and H3 increased by 133.95% compared with CK. The yield and quality of C. pilosula were the highest in the H3 treatment group, with the fresh yield of 6 858.33 kg·hm~(-2), 50.59% higher than CK, dry yield of 2 398.33 kg·hm~(-2), 76.54% higher than CK, and lobetyolin content of 0.56 mg·g~(-1), 45.22% higher than CK. Therefore, the stereoscopic traction height has a great influence on the photosynthetic characteristics, yield, and quality of C. pilosula. Particularly, the yield and quality of C. pilosula can be optimized and improved in the traction height treatment of H3(120 cm). This planting method is worth popularizing and applying in the cultivated management of C. pilosula.
Codonopsis ; Traction ; Photosynthesis ; Plant Leaves ; Plant Roots

Cyanobacteria are the only prokaryotes capable of oxygenic photosynthesis, which have potential to serve as "autotrophic cell factories". However, the synthesis of biofuels and chemicals using cyanobacteria as chassis are suffered from poor stress tolerance and low yield, resulting in low economic feasibility for industrial production. Thus, it's urgent to construct new cyanobacterial chassis by means of synthetic biology. In recent years, adaptive laboratory evolution (ALE) has made great achievements in chassis engineering, including optimizing growth rate, increasing tolerance, enhancing substrate utilization and increasing product yield. ALE has also made some progress in improving the tolerance of cyanobacteria to high light intensity, heavy metal ions, high concentrations of salt and organic solvents. However, the engineering efficiency of ALE strategy in cyanobacteria is generally low, and the molecular mechanisms underpinning the tolerance to various stresses have not been fully elucidated. To this end, this review summarizes the ALE-associated technical strategies and their applications in cyanobacteria chassis engineering, following by discussing how to construct larger ALE mutation library, increase mutation frequency of strains and shorten evolution time. Moreover, exploration of the construction principles and strategies for constructing multi-stress tolerant cyanobacteria, and efficient analysis the mutant libraries of evolved strains as well as construction of strains with high yield and strong robustness are discussed, with the aim to facilitate the engineering of cyanobacteria chassis and the application of engineered cyanobacteria in the future.
Technology ; Photosynthesis/genetics* ; Cyanobacteria/genetics* ; Light ; Biofuels

The biological characteristics,agronomic traits,yield traits,stress resistance,quality and photosynthetic characteristics among six lily varieties were compared in order to screen out the excellent lily varieties suitable for spread planting in Hunan province. Lilium longiflorum had the longest growth period,246 days,among these six lily varieties,while others were about 170 days. The leaves of L.longiflorum,self-selected variety,L. lancifolium and L. dauricum had higher chlorophyll content. No obvious difference was found in net photosynthetic rate,stomatal conductance,transpiration rate and intercellular CO2 concentration among all varieties. The self-selected variety had the highest theoretical and actual yield,2 543. 03,1 608. 65 kg per Mu(1 Mu≈666. 7 m2),respectively,but contents of polysaccharides and flavones in bulbs were lower. All of these six lily varieties can sowing,seedling emergence,growth,flowering,mature harvest in Hunan province. L. dauricum and L. lancifolium would be provided for edible lily. L. brownie and the self-selected variety are highly susceptible varieties. L. dauricum and L. lancifolium are suitable to plant widely in disease-prone regions,due to their strong resistance. L. brownie and L. lancifolium are preferred varieties for medicinal and food using for their good quality and higher contents of polysaccharides and flavones. L. davidii had lower theoretical and actual yield,so planting extension of it should be taken into account.
Chlorophyll ; Lilium ; Photosynthesis ; Plant Leaves ; Plant Roots

OBJECTIVETo compare the photosynthetic characteristics difference of different ploidy Rhodiola sachalinensis germplasm and provide the scientific basis for their cultivation.

METHODLI-6400/XT photosynthesis system was used to measure leaf light response curve and CO2 response curve of diploid and autotetraploid. Biomass, leaf area, stomatal characteristics and chlorophyll content differences were compared in the study.

RESULTStomata of the two germplasms were open during daytime obviously, and stomata conductance responded to the changes of light intensity and CO2 concentration which was not consistent with the characteristics of CAM (crassulacean acid metabolism) plants. Light compensation point of autotetraploid was significantly lower than that of the diploid, and light saturation points of both germplam were close, and their light saturation points were near 500 micromol x m(-2) x s(-1). Quantum efficiency of autotetraploid was significantly higher than the diploid, and the net photosynthetic rate of autotetraploid significantly higher than the diploid when light intensity was higher than 500 micromol x m(-2) x s(-1). Stomata conductance, transpiration rate of autotetraploid was also significantly higher than that of diploid. Biomass, leaf area, stomata diameter and chlorophyll content of autotetraploid were much higher than that of diploid, while the stomata density of autotetraploid was less than diploid.

CONCLUSIONThe results above provide scientific basis for the cultivation of different ploidy Rh. sachalinensi germplasm.