Mechanisms for minimizing height-related stomatal conductance declines in tall vines.

The ability to transport water through tall stems hydraulically limits stomatal conductance (gs ), thereby constraining photosynthesis and growth. However, some plants are able to minimize this height-related decrease in gs , regardless of path length. We hypothesized that kudzu (Pueraria lobata) prevents strong declines in gs with height through appreciable structural and hydraulic compensative alterations. We observed only a 12% decline in maximum gs along 15-m-long stems and were able to model this empirical trend. Increasing resistance with transport distance was not compensated by increasing sapwood-to-leaf-area ratio. Compensating for increasing leaf area by adjusting the driving force would require water potential reaching -1.9 MPa, far below the wilting point (-1.2 MPa). The negative effect of stem length was compensated for by decreasing petiole hydraulic resistance and by increasing stem sapwood area and water storage, with capacitive discharge representing 8-12% of the water flux. In addition, large lateral (petiole, leaves) relative to axial hydraulic resistance helped improve water flow distribution to top leaves. These results indicate that gs of distal leaves can be similar to that of basal leaves, provided that resistance is highest in petioles, and sufficient amounts of water storage can be used to subsidize the transpiration stream.

Comparing morphological, chemical and anti-diabetic characteristics of Puerariae Lobatae Radix and Puerariae Thomsonii Radix.

ETHNOPHARMACOLOGICAL RELEVANCE: Puerariae Lobatae Radix (PLR) and Puerariae Thomsonii Radix (PTR) are traditional Chinese medicines used for the treatment of diabetes and cardiovascular diseases. These two herbs are used interchangeably in clinical practice, even though they possess significantly different chemical profiles. In the case of Pueraria species, the misidentification is related to the multiple Chinese common names in clinical practice and variable pharmaceutical Latin names in different versions of the Pharmacopoeia of the People's Republic of China. In addition, there is lack of evidence demonstrating how the differences in the chemical profile would impact on the pharmacological activity of the two herbs. Therefore, the aim of this study was to compare the microscopic, phytochemical profiles and anti-diabetic activity of PLR and PTR so that the two species can be differentiated. MATERIALS AND METHODS: The microscopic characteristics of the PLR and PTR were observed and measured by an optical microscope. The major compounds were quantified by ultra-performance liquid chromatography (UPLC) and total flavonoid content (TFC) colorimetric assay. The free radical scavenging capacity was assessed by 2,2-diphenyl-2-picrylhydrazyl (DPPH) antioxidant assays. Anti-diabetic activity was determined by the inhibition of porcine pancreatic α-amylase and rat intestinal α-glucosidase activities. RESULTS: Microscopic results illustrated that the size of xylem vessels (PLR: 0.1390 ± 0.0184 mm; PTR: 0.0471 ± 0.0109 mm), number of fibre per bundle (PLR: 32.6800 ± 2.8780; PTR: 16.5900 ± 0.9982) and the size of fibre (PLR: 0.0075 ± 0.0003 mm(2); PTR: 0.0025 ± 0.0002 mm(2)) in PLR were significantly greater than that in PTR (p<0.01). PLR possessed a significantly lower total starch content (PLR: 0.5288 ± 1.2559 mg starch/g DM; PTR: 76.7954 ± 2.9905 mg starch/g DM) and total dietary fibre content (PLR: 4.2886 ± 0.3466 g/100g DM; PTR: 12.4148 ± 0.4541 g/100g DM) as compared to PTR. Isoflavonoids including puerarin, daidzin, genistin and daidzein were the major chemical constituents in both species. However, the average content of puerarin in PLR was found to be eleven times greater than that in PTR. Furthermore, the TFC, DPPH free radical scavenging capacity, anti-α-amylase and anti-α-glucosidase in the PLR extracts were 4.42, 4.91, 3.10 and 4.22 times greater than in the PTR extracts. CONCLUSIONS: This study provides a comprehensive investigation on the two medicinal valuable Pueraria species and allows differences to be ascertained. This information can be used to update monographs which will help practitioners and dispensers differentiate the herbs. Further study on the interchangeable use of PLR and PTR in clinical practice is urgently warranted.

[Microscopic anatomy of abnormal structure in root tuber of Pueraria lobata].

Puerariae Lobatae Radix, also known as Gegen, is a root derived from Pueraria lobata. Based on field investigation and the developmental anatomy of root tuber, we have elucidated the relationship between the growth of root tuber and the anomalous structure. The results of analysis showed that the root system of P. lobata was developed from seed and adventitious root and there existed root tuber, adventitious root and conductive root according to morphology and function. The root tuber was developed from adventitious root, its secondary structure conformed to the secondary structure of dicotyledon's root. With the development of root, the secondary phloem of root tuber appeared abnormal vascular tissue, which was distributed like ring in the outside of secondary vascular tissue. The root tuber might have 4-6 concentric circular permutation abnormal vascular tissuelobate, and was formed by the internal development of abnormal vascular tissue. The xylem and phloem of abnormal vascular tissue were the main body of the root tuber. The results reveal the abnormal anatomical structure development of P. lobata, also provides the theoretical basis for reasonable harvest medicinal parts and promoting sustainable utilization of resources of P. lobata.

Plant architecture and growth response of kudzu (fabaceae: Fabaceae) to simulated insect herbivory.

Kudzu [Pueraria montana variety lobata (Willd.) Maesen & S. M. Almeida] plant architecture and growth were compared for plants subjected to 4 wk of simulated herbivory (75% leaf cutting) and no damage. Simulated herbivory reduced above-ground and root biomass by 40 and 47%, respectively, whereas total vine length and average length of the 10 longest vines were reduced by 48 and 43%, respectively, compared with control plants. Plant architecture was also affected, with damaged plants showing a significantly reduced proportion of primary vines, shorter secondary vines, and reduced average internode distances compared with the control plants. In natural situations, these changes would reduce the ability of kudzu to compete for light and other resources by affecting the plant's climbing habit.

Authentication of Chinese Materia Medica decoction dregs. Part II: comparison before and after decoction of four Chinese Materia Medica that mainly comprise storage tissue.

Authentication of Chinese Materia Medica (CMM) decoction dregs is important for ensuring the efficacy and safety of CMM when they are used in decoction. If someone got worse or poisoned after taking a decoction while the formula is appropriate, the authentication of CMM dregs is the effective method to explore the reasons. Therefore, a systematic study on the authentication of CMM dregs was carried out. In this study, two pairs of easily confused CMM dregs, Fenge (Puerariae Thomsonii Radix) and Shanyao (Dioscoreae Rhizoma), Dihuang (Rehmanniae Radix) and Huangjing (Polygonati Rhizoma), which mostly comprise storage tissues, were investigated by comparing the morphological and microscopic characteristics. Fenge and Shanyao contain abundant starch granules. After decoction their dregs were hard, nonstarchy and horn-like. Fully gelatinized starch granules were found in the powder of Fenge dregs while incompletely gelatinized starch granules were occasionally found in the Shanyao dregs. In contrast, Dihuang and Huangjing contain water-soluble sugars. After decoction, their dregs were hard and brittle. Their parenchymatous cells were shrunken and unknown crystals were found under microscope. Hence, the morphological and microscopic characteristics of CMM before and after decoction were different, and different changes in the CMM dregs can be illustrated by the different nature of their ergastic substance. These differences could be used to authenticate CMM dregs.

White Kwao Krua variety classification by botanical characteristics and ISSR-Touchdown PCR technique.

White Kwao Krua [Pueraria candollei Grah. var. mirifica (Airy Shaw et Suvatabandhu) Niyomdham] is a herb used as an ingredient in supplementary and cosmetic. The tuberous roots of White Kwao Krua (WKK) contain estrogen-like substances. Seeds of WKK, collected from Prachuab Khiri Khan, were planted and propagated in the farm of Suranaree University of Technology, and their genetic backgrounds were ambiguous. Thirty six plants of WKK in the same age were sampled for classification using 7 botanical characteristics and DNA fingerprint by ISSR-Touchdown PCR technique. The relationship of the 7 botanical characteristics, using principle component analysis (PCA), showed the WKK plants fell into 3 groups. In the first group was plant number 34, which was distinguished from the other plants by its small leaf size. The second group consisted of 23 plants with elliptic leaf shape, acute leaf base, and acuminate leaf apex. The third group consisted of 12 plants with ovate leaf shape, obtuse leaf base, and cuspidate leaf apex. The ISSR-Touchdown PCR technique with 41 primers detected 355 loci of DNA with an average of 8.6 loci per primer. The sizes of DNA ranged between 280 bp to 1550 bp. Two hundred ninety three loci exhibited polymorphisms (82.54%) and the rest 62 loci were monomorphic (17.46%). The polymorphism information content (PIC) was between 0.0315-0.9779 (average 0.4779) and number of effective alleles per locus (Ne) ranged between 1.1250-1.8541 (average 1.5544). Unweighted pair group method with arithmetic mean (UPGMA), Jaccard similarity coefficient and PCA were used to find the construction of genetic relationship of WKK. The genetic similarity (GS) of WKK ranged between 0.50-0.86 (average 0.77). At the GS of 0.56 from cluster analysis, the WKK varieties could be divided into 2 major groups. The first group comprised of plant number 34 and 7, and the second group could be further divided in 2 subgroups at GS of 0.69. None of the WKK plants was identical in genetic, and they were expected to be derived from 5 genetic sources. These results showed that applying of the ISSR-Touchdown PCR technique could be used to classify WKK efficiently.

[Herbological investigation on traditional Chinese medicine gegen].

In this paper, herbological investigation was carried out into a large of Ben-Cao literature that concerned the origin, clinical use and other relevant aspects of Gegen, from which we can judge that Gegen used in ancient times match to that specified in the present Chinese Pharmacopoeia.