Alternate furrow irrigation for maize production in an arid area

Abstract A new irrigation method for maize production was designed and tested for yield and water use ef®ciency (WUE). A ®eld experiment was conducted in an arid area, with seasonal rainfall of 80 mm, over 2 years (1997 and 1998). Irrigation was applied through furrows in three ways: alternate furrow irrigation (AFI), ®xed furrow irrigation (FFI), and conventional furrow irrigation (CFI). AFI means that one of the two neighboring furrows was alternately irrigated during consecutive watering. FFI means that irrigation was ®xed to one of the two neighboring furrows. CFI was the conventional way where every furrow was irrigated during each watering. Each irrigation method was further divided into three sub-treatments with different irrigation amounts: 45, 30 and 22.5 mm water at each application. Results showed that root development was signi®cantly enhanced by AFI treatment. Primary root numbers, total root dry weight, and root density were all higher in AFI than in FFI and CFI treatments. Less irrigation signi®cantly reduced the total root dry weight and plant height in both FFI and CFI treatments but not as substantially with AFI treatments. The most surprising result was that AFI maintained high grain yield with up to 50% reduction in irrigation amount, while FFI and CFI all showed a substantial decrease in yield with reduced irrigation. As a result, WUE for irrigated water was substantially increased. We conclude that AFI is a way to save water in arid areas where maize production relies heavily on repeated irrigation.

Isolation of high quality RNA from Polyporus umbellatus (Pers.) Fries

Background: The dried sclerotium of medicinal fungus Polyporus umbellatus (Pers.) Fries has many pharmacological functions such as diuretic and anticancer activity, in which high-content polysaccharides may play an important role. However, RNA isolation is difficult in filamentous fungi and lacking in P. umbellatus. Results: Five methods for RNA extraction from five strains collected from four provinces were assessed for their ability to recover a high-quality RNA applicable for sequence-related amplification polymorphism (SRAP) PCR and GDP-D-mannose pyrophosphorylase (GMP) gene expression profiles. Both A260/A280 and A260/A230 ratios of the best Trizol Plus + RNAiso-mate for Plant Tissue method are around 2 with a yield of 1122.00 \ub1 0.21 ng \u3bcl-1. The Trizol method also showed good quality with the yield 469.60 ng \u3bcl-1. The SRAP PCR amplified clear and polymorphic bands in all five cDNA samples transcribed from RNA by using primer Me4-Em4. GMP gene fragment (1251 bp) was successfully amplified by RT-PCR, suggesting the integrity of isolated RNA. Conclusion:All these results showed that the total RNA isolated by this protocol is of sufficient quality for subsequent molecular applications

Involvement of PtPHR1 in phosphates starvation-induced alkaloid biosynthesis in Pinellia ternata (Thunb.) Breit

Nowadays, because of the great benefit to human health, more and more efforts have been made to increase the production of alkaloids in Pinellia ternata (Thunb.) Breit. Phosphate (Pi) plays a critical role in plant growth and development, as well as secondary metabolism. However, its effect and regulation mechanism of Pi signaling on alkaloid biosynthesis call for further exploration. Here, we reported that Pi starvation could induce alkaloid accumulation in P. ternata. We cloned a cDNA sequence encoding PtPHR1 from P. ternata, which was further identified by nuclear localization, transcription activity, and binding ability to the PHR1-binding sequence. We found that the transformation of PtPHR1 into the Arabidopsis phr1 mutant (designated as PtPHR1OE/phr1) led to the rescue of the phenotype of the phr1 mutant to that of the wild-type, including the expression level of Pi starvation-induced genes and anthocyanin accumulation. The combination of these biochemical and genetic experiments indicated that PtPHR1 was intended to have a role similar to that of AtPHR1 in Pi signaling and metabolic responses. Interestingly, we found that Pi starvation also induced the production of benzoic acid, an intermediate in the biosynthetic pathway of phenylpropylamino alkaloids. Furthermore, this induction effect was impaired in the phr1 mutant but partly recovered in PtPHR1OE/phr1 plants. Together, our data suggest that Pi starvation promoted benzoic acid-derived alkaloid biosynthesis in P. ternata under the control of PtPHR1. Our finding that PtPHR1 is involved in the regulation of Pi signaling on alkaloid biosynthesis shows a direct link between the Pi nutrient supply and secondary metabolism

Metabolic Profiles and cDNA-AFLP Analysis of Salvia miltiorrhiza and Salvia castanea Diel f. tomentosa Stib

Plants of the genus Salvia produce various types of phenolic compounds and tanshinones which are effective for treatment of coronary heart disease. Salvia miltiorrhiza and S. castanea Diels f. tomentosa Stib are two important members of the genus. In this study, metabolic profiles and cDNA-AFLP analysis of four samples were employed to identify novel genes potentially involved in phenolic compounds and tanshinones biosynthesis, including the red roots from the two species and two tanshinone-free roots from S. miltiorrhiza. The results showed that the red roots of S. castanea Diels f. tomentosa Stib produced high contents of rosmarinic acid (21.77 mg/g) and tanshinone IIA (12.60 mg/g), but low content of salvianolic acid B (1.45 mg/g). The red roots of S. miltiorrhiza produced high content of salvianolic acid B (18.69 mg/g), while tanshinones accumulation in this sample was much less than that in S. castanea Diels f. tomentosa Stib. Tanshinones were not detected in the two tanshinone-free samples, which produced high contents of phenolic compounds. A cDNA-AFLP analysis with 128 primer pairs revealed that 2300 transcript derived fragments (TDFs) were differentially expressed among the four samples. About 323 TDFs were sequenced, of which 78 TDFs were annotated with known functions through BLASTX searching the Genbank database and 14 annotated TDFs were assigned into secondary metabolic pathways through searching the KEGGPATHWAY database. The quantitative real-time PCR analysis indicated that the expression of 9 TDFs was positively correlated with accumulation of phenolic compounds and tanshinones. These TDFs additionally showed coordinated transcriptional response with 6 previously-identified genes involved in biosynthesis of tanshinones and phenolic compounds in S. miltiorrhiza hairy roots treated with yeast extract. The sequence data in the present work not only provided us candidate genes involved in phenolic compounds and tanshinones biosynthesis but also gave us further insight into secondary metabolism in Salvia

The Protein Kinase SmSnRK2.6 Positively Regulates Phenolic Acid Biosynthesis in Salvia miltiorrhiza by Interacting with SmAREB1

Subclass III members of the sucrose non-fermenting-1-related protein kinase 2 (SnRK2) play essential roles in both the abscisic acid signaling and abiotic stress responses of plants by phosphorylating the downstream ABA-responsive element (ABRE)-binding proteins (AREB/ABFs). This comprehensive study investigated the function of new candidate genes, namely SmSnRK2.3, SmSnRK2.6, and SmAREB1, with a view to breeding novel varieties of Salvia miltiorrhiza with improved stress tolerance stresses and more content of bioactive ingredients. Exogenous ABA strongly induced the expression of these genes. PlantCARE predicted several hormones and stress response cis-elements in their promoters. SmSnRK2.6 and SmAREB1 showed the highest expression levels in the leaves of S. miltiorrhiza seedlings, while SmSnRK2.3 exhibited a steady expression in their roots, stems, and leaves. A subcellular localization assay revealed that both SmSnRK2.3 and SmSnRK2.6 were located in the cell membrane, cytoplasm, and nucleus, whereas SmAREB1 was exclusive to the nucleus. Overexpressing SmSnRK2.3 did not significantly promote the accumulation of rosmarinic acid (RA) and salvianolic acid B (Sal B) in the transgenic S. miltiorrhiza hairy roots. However, overexpressing SmSnRK2.6 and SmAREB1 increased the contents of RA and Sal B, and regulated the expression levels of structural genes participating in the phenolic acid-branched and side-branched pathways, including SmPAL1, SmC4H, Sm4CL1, SmTAT, SmHPPR, SmRAS, SmCHS, SmCCR, SmCOMT, and SmHPPD. Furthermore, SmSnRK2.3 and SmSnRK2.6 interacted physically with SmAREB1. In summary, our results indicate that SmSnRK2.6 is involved in stress responses and can regulate structural gene transcripts to promote greater metabolic flux to the phenolic acid-branched pathway, via its interaction with SmAREB1, a transcription factor. In this way, SmSnRK2.6 contributes to the positive regulation of phenolic acids in S. miltiorrhiza hairy roots

Saikosaponin accumulation and antioxidative protection in drought-stressed Bupleurum chinense DC. plants

Dried root of Bupleurum spp. is one of the most popular ingredients in many oriental medicinal preparations. Potted Bupleurum chinense DC. seedlings were subjected to progressive drought stress by withholding irrigation followed by a rewatering phase. The changes in antioxidant system, hydrogen peroxide (H(2)O(2)), superoxide radicals (O(2)(-)), and malondialdehyde (MDA) contents as well as saikosaponin a (SSa) and saikosaponin d (SSd) content in B. chinense roots were investigated. Additionally, the antioxidant activity of the roots extract was evaluated. The results showed that B. chinense root appeared highly resistant to water deficit. Both SSa and SSd content increased with the progressive water deficit, however, decreased tinder severe drought conditions or after water recovery. Moderate drought treatment resulted in 83% increase in SSa content and 22% increase in SSd content compared to the well-hydrated treatment. And increased SSa and SSd content during drought were accompanied by enhanced O(2)(-) content and superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) activity until severe drought stress. Notably, in vitra antioxidant tests demonstrated that the lipid peroxidation inhibition capacity was positively correlated with the content of SSa and SSd, particularly significant at p=0.05 with SSd content. These results suggest that B. chinense roots exhibit effective antioxidative protection mechanism to withstand drought stress. And it could be speculated that drought-induced SSa and SSd accumulation in B. chinense roots may be stimulated via active oxygen species, and consequently involve in mitigating the oxidative damage due to its high anti-lipid peroxidation capacity. (c) 2009 Published by Elsevier B.V

Nutritional Composition, α-Glucosidase Inhibitory and Antioxidant Activities of Ophiopogon japonicus Tubers

Ophiopogon japonicus tubers have been widely used as food and traditional Chinese medicine in China. However, their nutritional composition has not been fully reported yet. This study aimed to analyze the nutritional composition of O. japonicus tubers. The α-glucosidase inhibitory and antioxidant activities of the extracts obtained from O. japonicus tubers were also evaluated by in vitro assays. The results indicated that O. japonicus tubers are rich in carbohydrates, proteins, minerals, and amino acids. Among four extracts, the n-butanol fraction (nBF) and chloroform/methanol extract (CME) of O. japonicus tubers had high amounts of total phenolic and flavonoid contents and exhibited good α-glucosidase inhibitory and antioxidant activities. The α-glucosidase inhibition of nBF was higher than acarbose. Overall, O. japonicus tubers are full of nutritional compounds and have good α-glucosidase inhibitory and antioxidant activities

Post-Harvest Processing Methods Have Critical Roles in the Contents of Active Ingredients of Scutellaria baicalensis Georgi

To find the best post-harvest processing method for Scutellaria baicalensis Georgi, we explored the effects of fresh and traditional processing on the active ingredients in S. baicalensis and evaluated three drying techniques to determine the optimal post-harvest processing technique. We quantified four active ingredients (baicalin, baicalein, wogonoside, and wogonin) in 16 different processed S. baicalensis samples that were harvested from Tongchuan, Shaanxi province, by HPLC (high-performance liquid chromatography). In addition, we performed a similarity analysis (SA), a hierarchical cluster analysis (HCA), and a principal component analysis (PCA) on the common peaks in S. baicalensis that were identified by the HPLC fingerprints. Compared to the traditional processing method, the fresh processing method could better preserve the four active ingredients in S. baicalensis, meanwhile, the similarity analysis (0.997–1.000) showed that the fresh processing was more similar to the traditional processing, and it did not change the type of 18 active ingredients in S. baicalensis. The cluster analysis results showed that the shade drying and sun drying methods results were more similar to each other, while the oven drying (60 °C) method results were clustered into one category. According to the results of the principal component analysis, S9, S7, and S8 had higher scores, and they were relatively well processed under these processing settings. Fresh processing could be an alternative to traditional processing; the moisture content was reduced to 24.38% under the sun drying condition, and it was the optimal post-harvest processing solution for S. baicalensis

Induction and in vitro alkaloid yield of calluses and protocorm-like bodies (PLBs) from Pinellia ternata

This study investigated the induction and in vitro alkaloid yield of calluses and protocorm-like bodies (PLBs) from Pinellia ternata (Thunb.) Berit (Araceae). We planned to use this material in future studies related to the mass production of medicinally valuable compounds and regulation of alkaloid metabolism. Different combinations of 2,4-dichlorophenoxyacetic acid (2,4-D), 6-benzyladenine (6-BA), kinetin (Kin), and alpha-naphthaleneacetic acid (NAA) were used to induce callus and PLB formation from P. ternata tuber explants. The results showed that three physiologically distinct calluses were induced by different combinations of 2,4-D, 6-BA, and Kin used in this study. The calluses differed in color, texture, differentiation status, and alkaloid content. The alkaloid content of the three calli types ranged from 0.0175% to 0.0293%. In comparison, the alkaloid content of field-grown tubers was 0.0072%. Many reports have indicated that 2,4-D suppresses the biosynthesis of secondary metabolites; however, our results show that 2,4-D promoted alkaloid production in Pinellia calluses. The combination of NAA + 6-BA induced PLB formation. The PLB alkaloid content of 0.0321% was 1.1 to 1.8 times higher than the alkaloid content of the calluses and 4.5 times higher than the field-grown tubers. In conclusion, the induction of calluses and PLBs with alkaloid content greater than that of field-grown tubers indicates the potential use of these tissue culture materials for bioprocessing alkaloids from P. ternata and for the study of alkaloid metabolism