Transcription Factors and Their Regulatory Roles in the Male Gametophyte Development of Flowering Plants.

Male gametophyte development in plants relies on the functions of numerous genes, whose expression is regulated by transcription factors (TFs), non-coding RNAs, hormones, and diverse environmental stresses. Several excellent reviews are available that address the genes and enzymes associated with male gametophyte development, especially pollen wall formation. Growing evidence from genetic studies, transcriptome analysis, and gene-by-gene studies suggests that TFs coordinate with epigenetic machinery to regulate the expression of these genes and enzymes for the sequential male gametophyte development. However, very little summarization has been performed to comprehensively review their intricate regulatory roles and discuss their downstream targets and upstream regulators in this unique process. In the present review, we highlight the research progress on the regulatory roles of TF families in the male gametophyte development of flowering plants. The transcriptional regulation, epigenetic control, and other regulators of TFs involved in male gametophyte development are also addressed.

Analysis of N6-methyladenosine reveals a new important mechanism regulating the salt tolerance of sugar beet (Beta vulgaris).

Salinity is an important environmental factor in crop growth and development. N6-methyladenosine (m6A) is an essential epigenetic modification that regulates plant-environment interaction. Sugar beet is a major sugar-yielding crop that has a certain tolerance to salt, but the dynamic response elicited by the m6A modification of transcripts under salt stress remains unknown. In this study, sugar beet was exposed to 300 mM NaCl to investigate its physiological response to high salinity and transcriptome-wide m6A modification profile. After the salt treatment, 7737 significantly modified m6A sites and 4981 differentially expressed genes (DEGs) were identified. Among the 312 m6A-modified DEGs, 113 hypomethylated DEGs were up-regulated and 99 hypermethylated DEGs were down-regulated, indicating a negative correlation between m6A modification and gene expression. Well-known salt tolerance genes (e.g., sodium/hydrogen exchanger 1, choline monooxygenase, and nucleoredoxin 2) and phospholipid signaling pathway genes (phosphoinositol-specific phospholipase C, phospholipase D, diacylglycerol kinase 1, etc.) were also among the m6A-modified genes. Further analysis showed that m6A modification may regulate salt-tolerant related gene expression by controlling mRNA stability. Therefore, changes in m6A modification may negatively regulate the expression of the salt-resistant genes in sugar beet, at least in part by modulating the stability of the mRNA via demethylase BvAlkbh10B. These findings could provide a better understanding of the epigenetic mechanisms of salt tolerance in sugar beets and uncover new candidate genes for improving the production of sugar beets planted in high-salinity soil.

Unique Features of the m6A Methylome and Its Response to Salt Stress in the Roots of Sugar Beet (Beta vulgaris).

Salt is one of the most important environmental factors in crop growth and development. N6-methyladenosine (m6A) is an epigenetic modification that regulates plant-environment interaction at transcriptional and translational levels. Sugar beet is a salt-tolerant sugar-yielding crop, but how m6A modification affects its response to salt stress remains unknown. In this study, m6A-seq was used to explore the role of m6A modification in response to salt stress in sugar beet (Beta vulgaris). Transcriptome-wide m6A methylation profiles and physiological responses to high salinity were investigated in beet roots. After treatment with 300 mM NaCl, the activities of peroxidase and catalase, the root activity, and the contents of Na+, K+, and Ca2+ in the roots were significantly affected by salt stress. Compared with the control plants, 6904 differentially expressed genes (DEGs) and 566 differentially methylated peaks (DMPs) were identified. Association analysis revealed that 243 DEGs contained DMP, and 80% of these DEGs had expression patterns that were negatively correlated with the extent of m6A modification. Further analysis verified that m6A methylation may regulate the expression of some genes by controlling their mRNA stability. Functional analysis revealed that m6A modifications primarily affect the expression of genes involved in energy metabolism, transport, signal transduction, transcription factors, and cell wall organization. This study provides evidence that a post-transcriptional regulatory mechanism mediates gene expression during salt stress by affecting the stability of mRNA in the root.

Proteomic Analysis of Auricularia auricula-judae Under Freezing Treatment Revealed Proteins and Pathways Associated With Melanin Reduction.

Auricularia auricula-judae is an edible nutrient-rich mushroom, which is a traditional medicinal resource in China. It is known that environment stimuli will affect the production of melanin by A. auricula-judae, but the mechanism of the effects of freezing treatment on melanin accumulation remains unknown. In the present study, the synthesis of melanin in A. auricula-judae was analyzed by physiological assays and a proteomics approach. Our findings showed that a longer freezing treatment causes a lighter color of A. auricula-judae fruiting bodies. The proteomic analysis showed that proteins involved in glycolysis/gluconeogenesis, tyrosine metabolism, ribosome, and arginine biosynthesis might contribute to the color differences in the A. auricula-judae after freezing treatment. This work will be expected to provide valuable information on the physiological and molecular mechanisms of freezing treatment on the color quality of A. auricula-judae.

Monoraphidium sp. HDMA-20 is a new potential source of α-linolenic acid and eicosatetraenoic acid.

BACKGROUND: ω-3 polyunsaturated fatty acids (PUFAs) are synthesized from α-Linolenic acid (ALA, C18:3ω3) and play important roles in anti-inflammatory and antioxidant responses in mammal cells. ALA is an essential fatty acid which cannot be produced within the human body and must be acquired through diet. The purpose of this study was to evaluate the potential of a novel microalgal strain (HDMA-20) as a source of ω-3 PUFAs including ALA and eicosatetraenoic acid (ETA, C20:4ω3). METHOD: Phylogenetic Neighbor-Joining analysis based on 18S ribosomal DNA sequence was used to identify the microalga strain HDMA-20. Autotrophic condition was chosen to cultivate HDMA-20 to reduce the cultivation cost. GC-MS was used to determine the fatty acid composition of HDMA-20 lipid. RESULTS: A microalgal strain (HDMA-20) from Lake Chengfeng (Daqing, Heilongjiang province, China) was found to accumulate high content of ω-3 PUFAs (63.4% of total lipid), with ALA and eicosatetraenoic acid (ETA, C20:4ω3) accounting for 35.4 and 9.6% of total lipid, respectively. Phylogenetic analysis based on 18S ribosomal DNA sequences suggested that the HDMA-20 belonged to genus Monoraphidium (Selenastraceae, Sphaeropleales) and its 18S rDNA sequence information turned out to be new molecular record of Monoraphidium species. The biomass productivity and lipid content of HDMA-20 were also investigated under autotrophic condition. The biomass productivity of HDMA-20 reached 36.3 mg L- 1 day- 1, and the lipid contents was 22.6% of dry weight. CONCLUSION: HDMA-20 not only represent an additional source of ALA, but also a totally new source of ETA. The high content of ω-3 PUFAs, especially ALA, of HDMA-20, makes it suitable as a source of nutrition supplements for human health. In addition, HDMA-20 exhibited good properties in growth and lipid accumulation, implying its potential for cost-effective ω-3 PUFAs production in future.

Isolation of a novel strain of Monoraphidium sp. and characterization of its potential for α-linolenic acid and biodiesel production.

α-Linolenic acid (ALA) is an essential fatty acid which cannot be synthesized de novo in mammals and must be ingested regularly in the diet. In this study, a microalgal strain named HDMA-11 was isolated from Lake Ming, China, and was found to accumulate a high ALA content (39.2% of total lipids). Phylogenetic neighbor-joining analysis indicated that HDMA-11 belongs to the genus Monoraphidium (Selenastraceae, Sphaeropleales) and its 18S ribosomal DNA sequence seemed to be a new molecular record of a Monoraphidium species. The fatty acid profiles, biomass productivity and lipid content of HDMA-11 were also investigated in autotrophic conditions. The high levels of polyunsaturated fatty acids in HDMA-11, especially ALA, make it suitable as a source of nutritional supplementation for human health. Furthermore, HDMA-11 exhibited good properties for biodiesel production, characterized by high lipid content (28.5% of dry weight), moderate biomass productivity (31.5 mg L-1 day-1) and a promising lipid profile.

Anticancer Phenolics from Dryopteris fragrans (L.) Schott.

Cancer is one of the most major diseases that threatens human health and life. The aim of this work was to obtain novel anticancer molecules from D. fragrans, a kind of medicinal plant. The structure of the new compound was identified using spectroscopic data (¹H-NMR, 13C-NMR and two dimensions NMR). Its anticancer properties were evaluated using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay against four human cells including lung cancer cells (A549), breast cancer cells (MCF-7), gastric cancer cells (SGC7901) and noncancerous human umbilical vein endothelial cells (HUVEC). A new phenylpropanoid-(E)-caffeic acid-9-O-ß-d-xylpyranosyl-(1→2)-ß-d-glucopyranosyl ester (1), with seven known compounds (2-8)-was isolated. The IC50 value of compound 1 against MCF-7 cells was 2.65 ± 0.14 µM, and the IC50 values of compound 8 against three cancer cells were below 20 µM.

Metabolite Profile of Salidroside in Rats by Ultraperformance Liquid Chromatography Coupled with Quadrupole Time-of-Flight Mass Spectrometry and High-Performance Liquid Chromatography Coupled with Quadrupole-Linear Ion Trap Mass Spectrometry.

In the present work, the salidroside metabolite profile in rat urine was investigated, and subsequently the metabolic pathways of salidroside were proposed. After administrations of salidroside at an oral dose of 100 or 500 mg/kg, rat urine samples were collected and pretreated with methanol to precipitate the proteins. The pretreated samples were analyzed by an Acquity ultraperformance liquid chromatography (UPLC) coupled with an HSS T3 column and detected by quadrupole time-of-flight mass spectrometry (Q-TOF-MS) or high-performance liquid chromatography coupled with hybrid triple-quadrupole linear ion trap mass spectrometry (HPLC/Q-trap-MS). A total of eight metabolites were detected and identified on the basis of the characteristics of their protonated ions in the urine samples. The results elucidated that salidroside was metabolized via glucuronidation, sulfation, deglycosylation, hydroxylation, methylation, and dehydroxylation pathways in vivo.

The therapeutic effect and possible harm of puerarin for treatment of stage III diabetic nephropathy: a meta-analysis.

CONTEXT: Diabetic nephropathy (DN) is the main cause of end-stage kidney disease in developed countries. Current therapy can slow the rate of progression of DN, but eventually end-stage renal failure will occur in a proportion of patients. Identification of new strategies and additional complementary and alternative therapies for treating DN are important. OBJECTIVE: The research team wanted to assess the beneficial and harmful effects of using puerarin plus angiotensin converting enzyme inhibitor (ACEI) compared with using only ACEI for treatment of individuals with stage III DN. DESIGN: The research team performed a meta-analysis of randomized, controlled trials (RCTs) by searching the following electronic databases: (1) the Cochrane Database of Systematic Reviews, (2) the Cochrane Central Register of Controlled Trials (CENTRAL), (3) PubMed, (4) EMBASE (Elsevier), (5) the Allied and Complementary Medicine Database (AMED), (6) the Chinese Biomedicine Database (CBM), (7) the China National Knowledge Infrastructure (CNKI), and (8) the Chinese Biomedical Journals (VIP), with no language restrictions, as well as databases of clinical trials. OUTCOME MEASURES: Measured outcomes included (1) urinary protein measured as urinary albumin excretion rate (UAER) (µg/min) and 24-h urine protein (24-h UP) (mg/24 h); (2) renal function measured as blood urea nitrogen (BUN) (mmol/L) and serum creatinine (SCr) (µmol/L); (3) α1-microglobulin (α1-MG) (mg/24 h) and endothelin-1 (ET-1) (ng/24 h); (4) end points (EPs); and (5) adverse events (AEs). RESULTS: Ten RCTs involving 669 participants were included. All trials were conducted and published in China. Treatment of DN with puerarin plus ACEI significantly decreased the UAER-P < .0001, MD = -23.43 (95% CI, -33.95 to -12.91), and had no effect on 24-h UP-P = .09, MD = -56.76 (95% CI, -122.65 to 9.12); BUN-P = .17, MD = -0.51 (95% CI, -1.24 to 0.21); and SCr-P = .26, MD = -4.43 (95% CI, -12.05 to 3.20). One trial reported abdominal discomfort and nausea (2 cases) in the treatment group. CONCLUSIONS: Puerarin may be a beneficial therapy for treating DN; however, this hypothesis needs to be proven by additional high-quality studies using large samples and multicenter evidence.

A systematic review and meta-analysis of type 2 diabetes mellitus treatment based on the "three-typed syndrome differentiation" theory in Chinese medicine.

OBJECTIVE: To evaluate the efficacy and safety of "Three-Typed Syndrome Differentiation" (TTSD) in treating type 2 diabetes mellitus patients. METHODS: A systematic review and meta-analysis was done based on the clinical diabetes treatment literature of the "TTSD". Overseas databases like the PubMed/MEDLINE, EMBASE, Cochrane Library and Cochrane Central Register of Controlled Clinical Trials, and China databases like China Biology Medicine Disc (CBM), Chinese national Knowledge Infrastructure (CNKI), Wanfang database, and VIP database, without limitation on language, were included with the time limitation from Jan 1982 to Dec 2012 by retrieval of relative original clinical research articles. RESULTS: Nineteen articles where contains 1,840 diabetes patients were obtained, in which no adverse reactions were reported. Of these, 14 literatures involved the effect of fasting blood glucose (FBG), 10 involved that of postprandial 2-h blood glucose (P2hBG), and 19 involved the overall efficacy based on the national Chinese medicine (CM) diagnosis and treatment standard of diabetes. All the meta-analysis results prefer to the "TTSD" groups (CM+Western medicine Based on TTSD). The results show that, beside the efficacy of Western medicine, the concentrations of FBG and P2hBG in "TTSD" groups continue to drop with statistical significance. For "TTSD" groups, the FBG subsequently dropped 1.03 mmol/L, 95%CI [1.24,0.82] P <0.00001), the P2hBG subsequently dropped 1.09 mmol/L, 95% CI [1.61, 0.57] (P <0.0001), and the overall efficacies benefit 3.46 times those of Western medicine alone, 95% CI [2.67,4.48] (P <0.00001). CONCLUSIONS: The CM by the diagnosis and treatment of type 2 diabetes based on TTSD might be safe and effective, and could better improve both blood glucose and the overall status of patients, including symptoms.

Evidence-based practice method of integrative Chinese and Western medicine based on literature retrieval through PICO question and complementary and alternative medicine topics.

An evidence-based practice method according to literature retrieval through PICO (Patients, Intervention, Comparison, Outcome) questions and complementary and alternative medicine (CAM) topics, which can obtain helpful evidence for guiding clinical practice, was introduced with a practical example in this paper. The knowledge of diseases and Western medicine treatment can be acquired by literature retrieval through PICO question, while searching by CAM topics may provide evidence for Chinese medicine (CM). Thus the author held that literature retrieval through both PICO question and CAM topics was an ideal evidence-based practice method for integrative Chinese and Western medicine (ICWM). However, since the standard in CM evidence hierarchy is still under study, the value of the CAM thematic retrieval method remains very limited. In the future, studies on the definition and hierarchy of CM evidences and the herb-drug interaction between Western and Chinese medicine during a combination therapy should be strengthened to improve the status of ICWM evidence-based practice.

Development of traditional Chinese medicine clinical data warehouse for medical knowledge discovery and decision support.

OBJECTIVE: Traditional Chinese medicine (TCM) is a scientific discipline, which develops the related theories from the long-term clinical practices. The large-scale clinical data are the core empirical knowledge source for TCM research. This paper introduces a clinical data warehouse (CDW) system, which incorporates the structured electronic medical record (SEMR) data for medical knowledge discovery and TCM clinical decision support (CDS). MATERIALS AND METHODS: We have developed the clinical reference information model (RIM) and physical data model to manage the various information entities and their relationships in TCM clinical data. An extraction-transformation-loading (ETL) tool is implemented to integrate and normalize the clinical data from different operational data sources. The CDW includes online analytical processing (OLAP) and complex network analysis (CNA) components to explore the various clinical relationships. Furthermore, the data mining and CNA methods are used to discover the valuable clinical knowledge from the data. RESULTS: The CDW has integrated 20,000 TCM inpatient data and 20,000 outpatient data, which contains manifestations (e.g. symptoms, physical examinations and laboratory test results), diagnoses and prescriptions as the main information components. We propose a practical solution to accomplish the large-scale clinical data integration and preprocessing tasks. Meanwhile, we have developed over 400 OLAP reports to enable the multidimensional analysis of clinical data and the case-based CDS. We have successfully conducted several interesting data mining applications. Particularly, we use various classification methods, namely support vector machine, decision tree and Bayesian network, to discover the knowledge of syndrome differentiation. Furthermore, we have applied association rule and CNA to extract the useful acupuncture point and herb combination patterns from the clinical prescriptions. CONCLUSION: A CDW system consisting of TCM clinical RIM, ETL, OLAP and data mining as the core components has been developed to facilitate the tasks of TCM knowledge discovery and CDS. We have conducted several OLAP and data mining tasks to explore the empirical knowledge from the TCM clinical data. The CDW platform would be a promising infrastructure to make full use of the TCM clinical data for scientific hypothesis generation, and promote the development of TCM from individualized empirical knowledge to large-scale evidence-based medicine.

[Effects of nitrogen forms on camptothecin content and its metabolism-related enzymes activities in Camptotheca acuminata seedlings].

OBJECTIVE: To investigate the effects of nitrogen forms on the camptothecin (CPT) content, tryptophan synthase (TSB) and tryptophan decarboxylase (TDC) activities in Camptotheca acuminata seedlings. METHOD: The seedlings of C. acuminata with 6 pairs of leaves were subjected to 5 different NH4(+) -N/NO3(-) -N ratio (0 : 100, 75 : 25, 50 : 50, 25 : 75, 100 : 0) treatments by sand culture in a greenhouse. The CPT content, TSB activity in the young leaves and TDC in the stem barks of the seedlings were determined by HPLC on the 15th, 30th, 45th, 60th and 75th day, respectively. RESULT: The obvious relationship between CPT content and nitrogen forms was observed. When NH4(+) - N /NO3(-) -N ratio was 25 : 75, CPT accumulation in young leaves displayed the best advantages (the highest value is 5.69 per thousand) and increased in the early 30 days of treatment and then declined. There was no obvious relationship between TSB activity in the young leaves and nitrogen forms. TDC activity in the stem bark was the highest when NH4(+) -N /NO3(-) -N ratio was 25 : 75, and the change of TDC activity paralleled to CPT content in the young leaves. CONCLUSION: A short-term treatment that NH4(+) -N /NO3(-) -N ratio was 25:75 may gain high CPT content in the young leaves through enhancing the TDC activity in the stem bark of C. acuminata seedlings.

[Effect of nitrogen on camptothecin content in Camptotheca acuminata seedlings].

OBJECTIVE: To investigate the effects of nitrogen concentration on the camptothecin (CPT) content in Camptotheca acuminata seedlings: METHOD: The seedlings of C. acuminata with 6 pair of leaves were subjected to five nitrogen concentrations treatments by sand culture in a greenhouse. The CPT content in the seedlings was determined by HPLC on the 20th, 35th, 50th, 65th and 80th day respectively. RESULT: The CPT content in the young leaves of C. acuminata seedlings supplied with different nitrogen concentration was significantly higher than that in other organs (P < 0.01), and it showed a single peak curve with the time course, the highest CPT content was observed on the 50th day after treatment. The CPT content in the young leaves obviously declined with increasing nitrogen concentration, and it reached the highest (6.72%) when nitrogen concentration was 4 mmol x L(-1), equal to 1.1 times that of 16 mmol x L(-1) nitrogen. CONCLUSION: The results demonstrate that proper deficient nitrogen stress can significantly enhance CPT accumulation in young leaves of C. acuminata seedlings.

Proteomics of pollen development and germination.

In higher plants, pollen grains represent the vestiges of a highly reduced male gametophyte generation. After germination, the pollen tube delivers the sperm cells by tip-growing to the embryo sac for fertilization. Besides the intrinsic importance for sexual reproduction, pollen development and germination serve as an attractive system to address important questions related to cell division, cell differentiation, polar growth, cell-cell interaction, and cell fate. Recently, pollen functional specification has been well-studied using multidisciplinary approaches. Here, we review recent advances in proteomics of pollen development and germination.

[Responses of larch seedling' s photosynthetic characteristics to nitrogen and phosphorus deficiency].

In this paper, the responses of larch seedling's photosynthetic characteristics to N and P deficiency were studied in greenhouse from April to September, 2002. On April 10, one-year-old larch seedlings, after their roots washed and sterilized, were transplanted into a plastic pot (diameter 30 cm, height 27 cm) containing sterilized and washed quartz sand, and supplied with complete nutrient solution (4 mmol NH4NO3 x L(-1), 1 mmol KH2PO4 x L(-1), 1 mmol KCl x L(-1), 1 mmol CaCl2 x L(-1), 0.6 mmol MgS4 x L(-1), 0.02 mmol FeCl3 x L(-1), 6 micromol MnC2 x L(-1), 0.016 mmol H3BO3 x L(-1), 0.3 micromol ZnCl2 x L(-1), 0.3 micromol CuCl2 x L(-1), and 0.3 micromol NaMoO4 x L(-1)). On May 20, the seedlings were treated with four different combinations of N and P supply, i.e., control (CK, 8 mmol N x L(-1) and 1 mmol P x L(-1)), low nitrogen supply (LN, 1 mmol N x L(-1) and 1 mmol P x L(-1)), low phosphorus supply (LP, 8 mmol N x L(-1) and 1/8 mmol P x L(-1)), and low nitrogen with low phosphorus supply (LN-LP, 1 mmol N x L(-1) and 1/8 mmol P x L(-1)). In treatment LN, the other nutrients were given as CK, while in treatment LP, the K level was adjusted by KCl, with the other nutrients kept as CK. On September 4, the net photosynthetic rate, chlorophyll fluorescence parameters, chlorophyll content, total soluble protein content, and N and P contents of the needle were determined. The results showed that in treatment LN, the N content, chlorophyll content, net photosynthetic rate (Pn), maximal PSII efficiency (Fv/Fm) and potential PSII activity (Fv/Fo) of the needle declined significantly by 37%, 31%, 58%, 22% and 57%, respectively, while in treatment LP, the N and P contents, chlorophyll content, total soluble protein content and Fv/Fm had no significant differences with CK, but the Pn and Fv/Fo was 13% lower than CK. The variation tendency and extent of Pn, chlorophyll fluorescence parameters, and other physiological indices in treatment LN-LP were similar to those in treatment LN.

[Seasonal variations in biomass and salidroside content in roots of Rhodiola sachalinensis as affected by gauze and red film shading].

Rhodiola sachalinensis A. Bor, a perennial herb, belonging to the family Crassulaceae, is mainly distributed in mountains at the altitudes of 1,700-2,500 m. It is a typical alpine plant and a very important medicinal plant with high activities of anti-fatigue, anti-senescence, and anti-radiation, due to the secondary metabolite salidroside in its root. Our previous findings have proven that red light promotes salidroside synthesis remarkably but decreases biomass insignificantly, resulting in a higher yield of salidroside in roots of Rh. sachalinensis in a greenhouse. In order to investigate the influences of shading and red light on seasonal variations in biomass and salidroside content in Rh. sachalinensis roots, the effects on 3 or 4 years old Rh. sachalinensis plants in a nursery in Daxinganling Mountain (124 degrees 02' E, 50 degrees 30' N) were studied in 2001. Compared to the control (CK) of full sunlight, 6 treatments with neutral transparent film and gauze, or red film alone had been conducted for 131 days. In treatment I, Rh. sachalinensis was shaded with neutral transparent film and gauze to achieve an irradiance 51.8% of full sunlight. In treatment II, the plants were shaded by red film alone, but the irradiance was as that in treatment I. In treatments III, IV, V and VI, neutral transparent film and gauze were originally used on May 8, then shifted to red film on Jun 3, July 4, August 4 and September 2, respectively and all experiments stopped on September 16, 2001. Rh. sachalinensis roots were harvested on 2-4th from June to September and finally on September 16, and root-biomass and salidroside content were measured. Root-biomass in plants decreased significantly under shading with neutral transparent film and gauze compared to the control with full sunlight, but little variations in salidroside content and yield. In comparison with shading by neutral transparent film and gauze, root-biomass reduced lightly and salidroside content and yield in roots were increased remarkably under red-film shading. At the end of the season, salidroside content under red light was 163% in 3-year-old and 155% in 4-year-old Rh. sachalinensis roots; whereas salidroside yields were 144% in 3-year-old and 145% in 4-year-old Rh. sachalinensis roots to those in plants under shading. The results also showed that the enhancement in the salidroside content and yield were little related to the duration of red film shading, which implied that in order to increase salidroside content and get higher salidroside yield, but less affect root-biomass, Rh. sachalinensis may be shaded with red film just several days before harvest.

[Ecological protection of medicinal woody plants].

Medicinal woody plants, especially medicinal tall trees, play a same important role in forest structure, ecological balance and timber production as other tree species in forest, and due to their additional medicinal values overuse of these trees is more intensive than others. Many medicinal materials are destructively obtained from plants such as roots or bark used as medicinal materials. The contradiction between the utilization and protection of medicinal woody plants becomes more and more incisive. In the present paper, based on the analysis of the utilized situation and specialty of medicinal woody plants, the trouble between the plants protection and utilization was observed, the method to solve it and the fundamental research work needs to be developed were discussed. The following aspects of researches were suggested to be conducted: (a) study on the distribution in organs, seasonal and age variations, and correlation with environmental factors of principal medicinal compositions in mature trees to clear the optimum of harvest and cultivation conditions; (b) study on the distribution in organs, seasonal and age variations, and correlation with environmental factors of principal medicinal compositions in saplings, especially the time course of the variation in medicinal compositions and biomass to achieve the optimal tree ages for the balance between biomass and production of medicinal products during saplings development; (c) study on the influence and regulation of environmental factors on medicinal compounds production in woody plants to look for the optimal cultivated conditions for optimizing the accumulation of biomass and medicinal chemicals; (d) further study on the regulatory mechanism of the induced production of main medicinal compositions by ecological factors at protein (key enzyme) and gene level to accumulate fundamental data for the enhancement of quality and quantity, and approach of new accesses to medicinal products using biological technology (cell culture and gene technology). Aimed at medicinal woody plants in Chinese forest resources, to develop the fundamental researches on resources protection and rational utilization will create many profound scientific significances. Firstly, medicinal woody plants are the important components of Chinese natural forest resources, so the problem for their protection and utilization, especially for that of tall trees, is quite remarkable and special. To reveal the internal contradictory between plant resources protection and its reasonable exploitation and exploit a practicable access to solve it will promote and accelerate the fulfillment of "natural forest protection project" in China. Secondly, traditional Chinese medicine is a main part of Chinese excellent ancestral culture, and the traditional utilizing models have been carried on for thousands of years. Accompanying with the development of human society, many unavoidable troubles such as the shortage of natural resources and the pollution of natural environment are more and more severely, which make the old models of the traditional Chinese medicine become more and more harmful and inaccessible to mankind. New substitutive approach to the utilization of traditional Chinese medicine, especially to that of Chinese medicinal woody plants will be one of the key methods to improve the present situation. Thirdly, traditional Chinese medicine, the cherish treasure of Chinese ancestral culture, need not only be preserved but also be developed. One of the main problems to restrict the extensive spread of the traditional Chinese medicine is its unstable quality, so to reach the stable quality and good quality is tightly linked to the improvement of traditional Chinese medicine. Hence the environmental regulation to the cultivation of medicinal plants, which can prove and guarantee the stable and high quality, will fit the demand on the production of medicinal plant material, and correspond to the goal of great efficacy and superior quality during the course of modernization of traditional Chinese medicine.