OBJECTIVETo study the effect of different water stress mode on photosynthesis characteristics of Aconitum barbaturnm, aimed at providing the theoretical basis for cultivating this kind of plant for the arid area.

METHODThe transplanted seedlings of A. barbatum were processed with fixed partial root zone drying(TI) ,alternate partial root zone drying(T2) and both partial root zone irrigation (T3) for three cycles,and relative parameters were measured.

RESULTThe net photosynthetic rate (Pn) in the treatment of T2 gradually increased and was higher than that in the treatment of T3 about 6.53%, mainly effected by non-stomatal factors. The water use efficiency (WUE) was higher than that in the treatments of T3 about 25.21%, while the transpiration rate (Tr) and the stomatal conductance was lower than those in the treatment of T1 and T3 separately. The maximum net photosynthesis rate (Pmax),the apparent quantum yield (AQY) and the dark respiration rate (Rd) were higher than those in comparison condition slightly.

CONCLUSIONThe alternate partial root zone drying is worth promoting vigorously, and it shall be a rational way to cultivate the A. barbatum under woodland.

Aconitum ; physiology ; Dehydration ; Photosynthesis ; physiology ; Plant Roots ; physiology ; Plant Stomata ; physiology ; Plant Transpiration ; physiology ; Seedlings ; physiology

The purpose of this experiment was to study the effects of different shading conditions on the growth,physiological characteristics and biomass allocation of Polygonatum cyrtonema,which offered a theoretical basis for its cultivation.Different light environments(100%,80%,60% and 35% light transmittance) were simulated with shading treatments.Growth and photosynthetic indexes of P.cyrtonema were measured and the variances were analyzed.The results show that shading decreased superoxide anion radical(O-·2)production rate and hydrogen peroxide(H_2O_2) accumulation,kept the activity of SOD,POD and CAT enzyme at a high level.Furthermore,The content of chlorophyll a and chlorophyll b,net photosynthetic rate(Pn),stomatal conductance(Gs),transpiration rate(Tr),maximal photochemical efficiency of photosystem Ⅱ(Fv/Fm),photochemical quenching index(q P) and effective quantum yield of photosystem II(ΦPSⅡ) of P.cyrtonema were increased while the intercellular CO2 concentration(Ci),Foand NPQ were decreased by shading.Shading is beneficial to P.cyrtonema growth,can increase the total biomass P.cyrtonema.The allocation proportion of biomass on the aerial portion of P.cyrtonema increased but underground parts decreased with increasing shading conditions.In this study,P.cyrtonema can grow well in shading conditions,shading is beneficial to the formation of the yield and quality of the rhizomes of P.cyrtonema,especially in 65% light transmittance.
Biomass ; Chlorophyll ; Chlorophyll A ; Photosynthesis ; Plant Leaves ; Plant Stomata ; Plant Transpiration ; Polygonatum ; growth & development ; physiology ; Sunlight

OBJECTIVECharacters of stem epidermis, leaf epidermis and stoma could be used as important microcosmic morphological characteristic when inheritance trend is studied in Ephedra breeding and identification.

METHODThe stomatic density, stoma major axis and mimor axis, stomatic morphylogy, characters of leaf and stem epidermis of 6 Ephedra plants' stems were examined by SEM.

RESULTThe stomatic density and characteristic of leaf epidermis and stem epidermis in six Ephedra species was differenc, there were no obvious morphological differences in stoma shape and size. The guard cells were covered with heavy cuticle and sunken stomata, which were the typical characteristics of xerophytes. The stomas of leaf lower epidermis were oblong or hexagon, but the stomas of steam epidermis were narrowed-oblong or dumbbell-shape, they all belonged to anomalous type.

CONCLUSIONThe stoma type and characters of Ephedra plants is stable and conservative, there was no obvious morphological differences in stoma shape and size between species, so it is difficult to distinguish different species by the variance of stomas, but that can be applyed to distinguish Ephedra from others at plant taxonomy.

Ephedra ; classification ; ultrastructure ; Microscopy, Electron, Scanning ; Plant Epidermis ; ultrastructure ; Plant Leaves ; ultrastructure ; Plant Stems ; ultrastructure ; Plant Stomata ; ultrastructure ; Plants, Medicinal ; ultrastructure ; Species Specificity

OBJECTIVETo accumulate taxonomic data of the leaf epidermal features of the medicinal species of Euonymus.

METHODTwenty-nine materials of 21 taxa (including 16 species, 4 varieties and 1 form) representing 5 sections of Euonymus are examined by using both of light microscopy and scanning electron microscopy.

RESULTThe form of epidermal cells in Euonymus is usually polygonal or irregular. The stomata were anomocytic in all the species examined except E. maackii and E. bungeanus var. semipersistens. Stomatal types of all species studied may be anomocytic, anisocytic, cycolocytic or the transitional types among them.

CONCLUSIONThe results show that some characteristics (including cuticular membrane, shape of guard cells, inner margin of outer stomatal rim, outer stomatal rim and stomata type) of the leaf epidermis can provide some anatomical evidence for the classification. The characteristics of leaf epidermis support following treatments: E. acanthocarpus var. longipes, E. acanthocarpus var. scandens and E. acanthocarpus var. sutchuanensis should be merged into E. acanthocarpus; E. bungeanus var. semipersistens should be merged into E. maackii; E. hamiltonianus f. lanceifolius should be merged into E. hamiltonianus.

China ; Euonymus ; chemistry ; classification ; Microscopy ; Microscopy, Electron, Scanning ; Plant Epidermis ; chemistry ; classification ; Plant Leaves ; chemistry ; classification ; Plant Stomata ; chemistry ; classification ; Plants, Medicinal ; chemistry ; classification

Based on the research of plant taxonomy and botanical investigation, microscopic characteristics of the root, stem, leaf transverse section and powder of Atropa belladonna were studied for identification of the herb. The research detailed and made clear to the description identification and microscopic characteristics of officinal parts of the herbs. The work provided reference for the identification of A. belladonna herbs and pieces of work in the future, as well as a theoretical basis for the further research, development, medicinal use and the upgrading of quality standards.
Atropa belladonna ; anatomy & histology ; cytology ; Microscopy ; methods ; Plant Epidermis ; anatomy & histology ; cytology ; Plant Leaves ; anatomy & histology ; cytology ; Plant Roots ; anatomy & histology ; cytology ; Plant Stems ; anatomy & histology ; cytology ; Plant Stomata ; anatomy & histology ; cytology ; Plants, Medicinal ; anatomy & histology ; cytology

Production of reactive oxygen species (ROS) is a conserved immune response primarily mediated by NADPH oxidases (NOXs), also known in plants as respiratory burst oxidase homologs (RBOHs). Most microbe-associated molecular patterns (MAMPs) trigger a very fast and transient ROS burst in plants. However, recently, we found that lipopolysaccharides (LPS), a typical bacterial MAMP, triggered a biphasic ROS burst. In this study, we isolated mutants defective in LPS-triggered biphasic ROS burst (delt) in Arabidopsis, and cloned the DELT1 gene that was shown to encode RBOHD. In the delt1-2 allele, the antepenultimate residue, glutamic acid (E919), at the C-terminus of RBOHD was mutated to lysine (K). E919 is a highly conserved residue in NADPH oxidases, and a mutation of the corresponding residue E568 in human NOX2 has been reported to be one of the causes of chronic granulomatous disease. Consistently, we found that residue E919 was indispensable for RBOHD function in the MAMP-induced ROS burst and stomatal closure. It has been suggested that the mutation of this residue in other NADPH oxidases impairs the protein's stability and complex assembly. However, we found that the E919K mutation did not affect RBOHD protein abundance or the ability of protein association, suggesting that the residue E919 in RBOHD might have a regulatory mechanism different from that of other NOXs. Taken together, our results confirm that the antepenultimate residue E is critical for NADPH oxidases and provide a new insight into the regulatory mechanisms of RBOHD.
Agrobacterium tumefaciens/metabolism* ; Alleles ; Arabidopsis/metabolism* ; Arabidopsis Proteins/genetics* ; Gene Expression Regulation, Plant ; Genetic Techniques ; Humans ; Lipopolysaccharides/metabolism* ; Luminescence ; Mutation ; NADPH Oxidase 2/chemistry* ; NADPH Oxidases/genetics* ; Plant Stomata/metabolism* ; Protein Domains ; Reactive Oxygen Species/metabolism* ; Nicotiana/metabolism*