Transcriptomic and metabolomic profiling provide insight into the role of sugars and hormones in leaf senescence of Pinellia ternata.

KEY MESSAGE: The interaction network and pathway map uncover the potential crosstalk between sugar and hormone metabolisms as a possible reason for leaf senescence in P. ternata. Pinellia ternata, an environmentally sensitive medicinal plant, undergoes leaf senescence twice a year, affecting its development and yield. Understanding the potential mechanism that delays leaf senescence could theoretically decrease yield losses. In this study, a typical senescent population model was constructed, and an integrated analysis of transcriptomic and metabolomic profiles of P. ternata was conducted using two early leaf senescence populations and two stay-green populations. The result showed that two key gene modules were associated with leaf senescence which were mainly enriched in sugar and hormone signaling pathways, respectively. A network constructed by unigenes and metabolisms related to the obtained two pathways revealed that several compounds such as D-arabitol and 2MeScZR have a higher significance ranking. In addition, a total of 130 hub genes in this network were categorized into 3 classes based on connectivity. Among them, 34 hub genes were further analyzed through a pathway map, the potential crosstalk between sugar and hormone metabolisms might be an underlying reason of leaf senescence in P. ternata. These findings address the knowledge gap regarding leaf senescence in P. ternata, providing candidate germplasms for molecular breeding and laying theoretical basis for the realization of finely regulated cultivation in future.

Integrated analysis of metabolome and transcriptome reveals key candidate genes involved in flavonoid biosynthesis in Pinellia ternata under heat stress.

Pinellia ternata (Thunb.) Breit. is an important traditional Chinese medicinal herb and very sensitive to high temperatures. To gain a better understanding of flavonoid biosynthesis under heat stress in P. ternata, we performed integrated analyses of metabolome and transcriptome data. P. ternata plants were subjected to a temperature of 38 °C, and samples were collected after 10 d of treatment. A total of 502 differential accumulated metabolites and 5040 different expressed transcripts were identified, with flavonoid biosynthesis predominantly enriched. Integrated metabolomics and transcriptome analysis showed that high temperature treatment upregulated the expression of CYP73A and downregulated the expression of other genes (such as HCT, CCoAOMT, DFR1, DFR2), which might inhibit the biosynthesis of the downstream metabolome, including such metabolites as chlorogenic acid, pelargonidin, cyanidin, and (-)-epigallocatechin in the flavonoid biosynthesis pathway. The transcription expression levels of these genes were validated by real-time PCR. Our results provide valuable insights into flavonoid composition and accumulation patterns and the candidate genes participating in the flavonoid biosynthesis pathways under heat stress in P. ternata.

Effects and Components of Herb Pair Huanglian-Banxia on Diabetic Gastroparesis by Network Pharmacology.

Diabetic gastroparesis (DGP) is a serious and chronic complication of long-standing diabetes mellitus, which brings a heavy burden to individuals and society. Traditional Chinese medicine (TCM) is considered a complementary and alternative therapy for DGP patients. Huanglian (Coptidis Rhizoma, HL) and Banxia (Pinelliae Rhizoma, BX) combined as herb pair have been frequently used in TCM prescriptions, which can effectively treat DGP in China. In this article, a practical application of TCM network pharmacological approach was used for the research on herb pair HL-BX in the treatment of DGP. Firstly, twenty-seven potential active components of HL-BX were screened from the TCMSP database, and their potential targets were also retrieved. Then, the compound-target network and PPI network were constructed from predicted common targets, and several key targets were found based on the degree of the network. Next, GO and KEGG enrichment analyses were conducted to obtain several significantly enriched terms. Finally, the experimental verification was made. The results demonstrated that network pharmacological approach was a powerful means for identifying bioactive ingredients and mechanisms of action for TCM. Network pharmacology provided an effective strategy for TCM modern research.

Transcriptomic analysis of short-term heat stress response in Pinellia ternata provided novel insights into the improved thermotolerance by spermidine and melatonin.

Heat stress has been a major environmental factor limiting the growth and development of Pinellia ternata which is an important Chinese traditional medicine. It has been reported that spermidine (SPD) and melatonin (MLT) play pivotal roles in modulating heat stress response (HSR). However, the roles of SPD and MLT in HSR of P. ternata, and the potential mechanism is still unknown. Here, exogenous SPD and MLT treatments alleviated heat-induced damages in P. ternata, which was supported by the increased chlorophyll content, OJIP curve, and relative water content, and the decreased malondialdehyde and electrolyte leakage. Then, RNA sequencing between CK (control) and Heat (1 h of heat treatment) was conducted to analyze how genes were in response to short-term heat stress in P. ternata. A total of 14,243 (7870 up- and 6373 down-regulated) unigenes were differentially expressed after 1 h of heat treatment. Bioinformatics analysis revealed heat-responsive genes mainly included heat shock proteins (HSPs), ribosomal proteins, ROS-scavenging enzymes, genes involved in calcium signaling, hormone signaling transduction, photosynthesis, pathogen resistance, and transcription factors such as heat stress transcription factors (HSFs), NACs, WRKYs, and bZIPs. Among them, PtABI5, PtNAC042, PtZIP17, PtSOD1, PtHSF30, PtHSFB2b, PtERF095, PtWRKY75, PtGST1, PtHSP23.2, PtHSP70, and PtLHC1 were significantly regulated by SPD or MLT treatment with same or different trends under heat stress condition, indicating that exogenous application of MLT and SPD might enhance heat tolerance in P. ternata through regulating these genes but may with different regulatory patterns. These findings contributed to the identification of potential genes involved in short-term HSR and the improved thermotolerance by MLT and SPD in P. ternata, which provided important clues for improving thermotolerance of P. ternata.

Phenotypic and Transcriptomic Analysis of Two Pinellia ternata Varieties T2 line and T2Plus line.

Pinellia (Pinellia ternata (Thunb.) Breit.), as important medicinal plant, has been used to treat various ailments for a long time. The sixteen ploid plant (2n = 16 * 13 = 208) Pinellia T2Plus line was obtained from an octoploid (2n = 8 * 13 = 104) T2 line by chromosome-doubling technique. Compared with T2 line, the content of various medicinal components (polysaccharide, guanosine, adenosine and ephedrine) was increased in T2Plus line. In this study, the transcriptome of T2 line and T2Plus line were characterized by RNA sequencing (RNA-seq) technology. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways enrichment analysis on differential expressed unigenes (DEGs) revealed that multiple metabolic pathway were enriched significantly, such as 'Starch and sucrose metabolism', 'Purine metabolism', 'Photosynthesis' and six transcription factors (MYB, WRKY, bHLH, lateral organ boundaries domain (LBD), homeodomain-zipper (HD-ZIP) and Ethylene-responsive factor (ERF)) play a key role in difference of transcriptome between T2 line and T2Plus line. These metabolic pathways and transcription factors may play an important role in the difference of medicinal components and epigenetic features between these two Pinellia cultivars. This conclusion provides a robust theoretical basis for the mechanism of the formation of medicinal ingredients in Pinellia cultivars.

Metabolomic analysis of raw Pinelliae Rhizoma and its alum-processed products via UPLC-MS and their cytotoxicity.

Alum-processing is a traditional method to attenuate the toxicity of Pinelliae Rhizoma (tubers of Pinellia ternate, PT). The present study aimed at investigating the chemical and cytotoxic changes during alum processing. Metabolomic profiles of raw and alum-processed PT were studied based on ultra-performance liquid chromatography coupled with Orbitrap mass spectrometry. More than 80 chemicals in positive MS mode and 40 chemicals in negative MS mode, such as organic acids, amino acids, glucosides and nucleosides, were identified after multivariate statistical analysis, including principal component analysis and orthogonal partial least-square discriminant analysis. Almost all of the identified chemical markers were significantly decreased ~10- to 100-fold after alum processing. Meanwhile, the correlations between the chemical markers were assimilated to a positive coefficient from disorderly distribution during the processing. Raw PT extracts could inhibit the proliferation of human carcinoma cells (HCT-116, HepG2, and A549) at the rate of 40.5, 24.8 and 31.6% more strongly than processed PT. It was concluded that the alum processing of PT could decrease the number of actively water-soluble principles at the same time as decreasing toxicity. Given the water-insoluble property of toxic calcium oxalate raphides in PT, we suggest that a more scientific processing method should be sought.

Comparisons of the pharmacokinetic profile of four bioactive components after oral administration of gan-sui-ban-xia decoction plus-minus gansui and gancao drug combination in normal rats.

Gan-Sui-Ban-Xia Decoction (GSBXD) was first presented by Zhang Zhongjing in the book Synopsis of Golden Chamber during the Han Dynasty period. The formula was then used for the treatment of persistent fluid retention with floating pulse in Traditional Chinese Medicine (TCM), which in modern medicine is known as malignant ascites. Here, a rapid liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed for the determination of glycyrrhizinic acid, liquiritin, paeoniflorin, albiflorin after oral administration of GSBXD plus-minus Gansui and Gancao anti-drug combination to investigate the possible pharmacokinetic profile differences of different prescriptions with GSBXD in normal rats. The differences of pharmacokinetic parameters among groups were tested by the Student's t-test with p < 0.05 as the level of significance. Significant differences were found between the Gansui and Gancao anti-drug combination and other herbs in GSBXD on pharmacokinetic profile of glycyrrhizinic acid, liquiritin, paeoniflorin and albiflorin. The obtained knowledge might contribute to the rationality of the clinic use of GSBXD and also reveal the compatibility conditions of the Gansui and Gancao anti-drug combination.

[Effects of Ca2+ on photosynthetic parameters of Pinellia ternata and accumulations of active components in heat stress].

OBJECTIVE: To study the effect of exogenous Ca2+ on photosynthetic parameters of Pinellia ternate and accumulations of active components under high temperature stress. METHOD: The pigment contents of P. ternata leaves, photosynthesis parameters and chlorophyll fluorescence parameters of P. ternata leaves, the contents of guanosine, adenosine and polysaccharide in P. ternata tubers were measured based on different concentrations of exogenous Ca2+ in heat stress when the plant height of P. ternata was around 10 cm. RESULT: The contents of total chlorophyll and ratio of chlorophyll a/b were relatively higher by spaying Ca2+. Compared with the control, spaying 6 mmol x L(-1) Ca2+ significantly enhanced the net photosynthetic rate (Pn), transpiration (Tr) and stomatal limitation (L8), but reduced intercellular CO2 concentration (C) in P. ternata leaves. With the increase of Ca2+ concentration, maximal PS II efficiency (Fv/Fm), actual photosynthetic efficiency (Yield) and photochemical quenching coefficient (qP) initially increased and then decreased, however, minimal fluorescence (Fo) and non-photochemical quenching coefficient (NPQ) went down first and then went up. The contents of guanosine and polysaccharide and dry weight of P. ternata tubers showed a tendency of increase after decrease, and the content of adenosine increased with the increase of Ca2+ concentration. The content of guanosine and polysaccharide in P. ternata tubers and its dry weight reached maximum when spaying 6 mmol x L(-1) Ca2+. CONCLUSION: With the treatment of calcium ion, the inhibition of photosynthesis and the damage of PS II system were relieved in heat stress, which increased the production of P. ternata tubers.

ß-Elemene, a compound derived from Rhizoma zedoariae, reverses multidrug resistance mediated by the ABCB1 transporter.

In the present in vitro study, we examined the effect of the compound ß-elemene on the response of KB-C2 cells overexpressing the ABCB1 transporter to specific antineoplastic compounds. The MTT assay was used to determine the effects of ß-elemene in combination with other anticancer drugs on ABCB1-overexpressing cancer cell lines. Furthermore, we used [3H]-paclitaxel accumulation, efflux assay, immunofluorescence experiments, western blot assays and docking analysis to ascertain the mechanism of action of ß-elemene. The incubation of KB-C2 cells overexpressing ABCB1 transporter with ß-elemene (100 µM) significantly augmented the antineoplastic efficacy of colchicine, vinblastine and paclitaxel when compared to KB-C2 cells incubated with these drugs alone. In HEK293 cells overexpressing the ABCB1 transporter, ß-elemene significantly increased the cytotoxicity of paclitaxel. In addition, 100 µM of ß-elemene significantly increased the accumulation of [3H]-paclitaxel and this was due to a decrease in [3H]-paclitaxel efflux when compared to controls. The incubation of KB-C2 cells with ß-elemene (100 µM) for 72 h did not significantly alter the expression of ABCB1 protein levels. Immunofluorescence experiments indicated that ß-elemene did not significantly alter the subcellular localization of the ABCB1 transporter. Docking analysis indicated that ß-elemene binds to the drug-binding site of ABCB1 transporter. Finally, ß-elemene at 100 µM partially (~50%) increased the sensitivity of the BCRP-overexpressing cell line, NCI-H460/MX20, to mitoxantrone, but ß-elemene did not significantly alter the resistance of MRP1-transfected HEK293/MRP1 cells to vincristine. Overall, our in vitro findings indicated that ß-elemene potentiates the cytotoxic effects of various antineoplastic drugs in cell lines overexpressing the ABCB1 transporter and that this is due to the inhibition of the efflux component of the ABCB1 transporter.

Characterization of secondary metabolites from the raphides of calcium oxalate contained in three araceae family plants using laser microdissection and ultra-high performance liquid chromatography-quadrupole/time of flight-mass spectrometry.

The dried stem tubers of Pinellia ternata (Thunb.) Breit, P. pedatisecta Schott and Typhonium flagelliforme (Lodd.) Blume from the Araceae family are used as Chinese medicines, namely Banxia, Zhangye Banxia and Shui Banxia, respectively. They have been reported to have a strong irritative effect on mucosa. Previous studies have indicated that the pure raphides of calcium oxalate contained in the stem tubers of three plants have attributed to this strong irritation. However, the processed products of the stem tubers of P. ternata, including Fabanxia, Qingbanxia and Jiangbanxia, have been found to have no irritative effects on mucosa. Currently, the secondary metabolites from the raphides of calcium oxalate contained in the stem tubers of P. ternata with its processed products, P. pedatisecta and T. flagelliforme were analyzed by means of laser microdissection and ultra-high performance liquid chromatography-quadrupole/ time of flight-mass spectrometry. The results indicate that the stem tubers of P. ternata P. pedatisecta and T. flagelliforme mainly contain amino acids, fatty acids, cyclic dipeptides and alkaloids. The secondary metabolite profile of the stem tuber of P. ternata was different from those of its processed products, Fabanxia, Qingbanxia and Jiangbanxia. However, the secondary metabolites from their raphides of calcium oxalate all contained beta-sitosterol, sitosterol palmitate, trigonelline, octadecenoic acid, pedatisectine A and thymidine. The raphides of calcium oxalate from P. ternata, P. pedatisecta and T. flagelliforme do not include any specific irritants. The results indicated that the irritation induced by raphides of calcium oxalate of three Araceae family plants is not relevant to the secondary metabolites but relates to the special needle shape.

[Effect of NH4(+) -N/NO3(-)-N ratio in applied supplementary fertilizer on nitrogen metabolism and main chemical composition of Pinellia ternata].

OBJECTIVE: To study the effect of nitrogen forms on nitrogen metabolism and main chemical composition of Pinellia ternate. METHOD: Through the soilless cultivation experiment and based at the same nitrogen level and different NH4(+) -N/NO3(-) -N ratios, nitrate reductase (NR) activity, glutamine synthetase (GS) activity, the content of nitrate nitrogen and ammonium nitrogen in different parts of P. ternate were determined. The contents of total alkaloid, free total organic acids and guanosine in the tuber were determined. The yield of bulbil and tuber was calculated. RESULT: The test results showed that, with the NH4(+) -N/NO3(-) -N ratio increasing, the activity of nitrate reductase decreased, the content of nitrate nitrogen in the leaves, petioles and tuber increasing initially, then decreased, and the content of nitrate nitrogen in the root decreased. Meanwhile, with the NH4(+) -N/NO3(-) -N ratio increasing, the activity of glutamine synthetase in the leaves, petioles and root increased, the activity of glutamine synthetase in the tuber increasing initially, then decreased. The contents of ammonium nitrogen in the leaves, tuber and root increased initially, then decreased, and the contents of ammonium nitrogen in the petioles increased with the NH4(+)(-N/NO3(-)-N ratio increasing. The yield of bulbil and tuber were the highest at the NH4(+)-N/NO3(-) -N ratio of 75: 25. The content of total alkaloid and guanosine in the tuber were the highest at the NH4(+)-N/NO3(-) -N ratio of 0: 100, and the contents were 0.245% and 0.0197% respectively. With the NH4(+)-N/NO3(-) -N ratio of 50: 50, the content of free total organic acids was the highest, it reached 0.7%, however, the content of free total organic acids was the lowest at the NH4(+) -N/NO3(-) -N ratio of 0: 100. CONCLUSION: Nitrogen fertilization significant influences the nitrogen metabolism, the yield and main chemical composition of P. ternate.

Microarray and degradome sequencing reveal microRNA differential expression profiles and their targets in Pinellia pedatisecta.

MicroRNAs (miRNAs) are endogenous small non-coding RNAs which play a critical role in gene regulation in plants. Pinelliapedatisecta is one of the most important herbs in traditional Chinese medicine, but there are no microRNAs of Pinelliapedatisecta were deposited in miRBase and the research of the related miRNA biological functions is still insufficient. To detect Pinelliapedatisecta miRNAs and discover their expression difference with Pinelliaternata, we carried out a microarray profiling. A total of 101 miRNAs belonging to 22 miRNA families were detected both in Pinelliapedatisecta and Pinelliaternata respectively, among them 21 miRNAs showed their differentially expression. GO (gene ontology) term enrichment analysis of the target genes of differential expression miRNAs reveal that these miRNAs mainly affect the reproduction, transcription factor activity and plant developmental process. To elucidate the target function of miRNAs, we constructed a degradome library from Pinellia pedatisecta leaf. The result showed that a total of 18 transcript were identified as targets of miRNAs and further analysis indicated that miR156 and miR529 may function together to repress SPL14.

A comparative proteomic analysis of Pinellia ternata leaves exposed to heat stress.

Pinellia ternata is an important traditional Chinese medicinal plant. The growth of P. ternata is sensitive to high temperatures. To gain a better understanding of heat stress responses in P. ternata, we performed a comparative proteomic analysis. P. ternata seedlings were subjected to a temperature of 38 °C and samples were collected 24 h after treatment. Increased relative ion leakage and lipid peroxidation suggested that oxidative stress was frequently generated in rice leaves exposed to high temperature. Two-dimensional electrophoresis (2-DE) was used to analyze heat-responsive proteins. More than 600 protein spots were reproducibly detected on each gel; of these spots, 20 were up-regulated, and 7 were down-regulated. A total of 24 proteins and protein species were successfully identified by MALDI-TOF/TOF MS. These proteins and protein species were found to be primarily small heat shock proteins (58%) as well as proteins involved in RNA processing (17%), photosynthesis (13%), chlorophyll biosynthetic processes (4%), protein degradation (4%) and defense (4%). Using 2-DE Western blot analysis, we confirmed the identities of the cytosolic class II small heat shock protein (sHSPs-CII) identified by MS. The expression levels of four different proteins [cytosolic class I small heat shock protein (sHSPs-CI), sHSPs-CII, mitochondrial small heat shock protein (sHSPs-MIT), glycine-rich RNA-binding protein (GRP)] were analyzed at the transcriptional level by quantitative real-time PCR. The mRNA levels of three sHSPs correlated with the corresponding protein levels. However, GRP was down-regulated at the beginning of heat stress but then increased substantially to reach a peak after 24 h of heat stress. Our study provides valuable new insight into the responses of P. ternata to heat stress.

[Effect of light quality on growth and quality of Pinellia ternata].

Measuring the content of soluble reducing sugar, total sugar, soluble protein, guanosine, alkaloids, and succinic acid of Pinellia ternata tuber were measured by anthrone-sulfuric acid colorimetric method, Coomassie brilliant blue method, RP-HPLC, reverse potentiometric titration, acid dye colorimetry, respectively. The result showed that yellow light could promote the growth and development of P. ternata and increase the content of soluble reducing sugar, total sugar, alkaloids, and succinic acid. Under blue light could promote the content of soluble protein and guanosine. Red and yellow light increased the content of chlorophyll a and chlorophyll b, contrastively blue light reduced the content of chlorophyll a and chlorophyll b. White film through the most uniform spectrum was most conducive to the synthesis of chlorophyll a. As single film, blue film, yellow film were more conducive to the synthesis of chlorophyll a, green film and red film had been relatively beneficial to the synthesis of chlorophyll b. Bulbil formed the largest number and the biggest propagation coefficient of P. ternata under red light showed that it could increase the production of P. ternata under red light.

[Dynamic accumulation of dry matter and active element in Pinellia ternata of Taizhou].

OBJECTIVE: To study the dynamic accumulation of dry matter and index components and provide reference to the manual cultural technique of Pinellia ternata. METHOD: Seedlings of Taizhou P. ternata were used as the pot experiment material, and the contents of free total organic acid and guanosine of each organ were determined at different stages of spring and autumn period. RESULT: P. ternata had two growth climax in spring and autumn. Under the same condition of cultivation and management, dry matter largely accumulated in spring. The contents of free total organic acid and guanosine was ascending during the growth period, but dropped during sprout tumble bolting and sprout tumble stage. CONCLUSION: High temperature and bolting affect the accumulation of organic acids significantly, it is reasonable to prevent the temperature stress in production.

[Genetic transformation of Pinellia ternata with Agrobacterium tumefaciens-mediated sHSP genes].

OBJECTIVE: To establish an efficient genetic transformation system of Pinellia ternata. METHOD: With petioles from test-tube seedlings of P. ternata as explants, Agrobacterium tumefaciens mediation method was adopted to explore the effect of phenolic substances, A. tumefaciens's concentration, infection time, pre-incubation time and co-cultivation time on genetic transformation efficiency of P. ternata. RESULT AND CONCLUSION: The genetic transformation efficiency could be effectively enhanced by infecting in A. tumefaciens culture containing AS 40 mg x L(-1) for 15 min for three days. The petioles were put into the differentiation medium containing 150 mg x L(-1) Kan and 350 mg x L(-1) Carb to screening and cultivation. After around 30 days, microtubers could be observed at both sides of the petioles. Gus staining and PCR verification on the regenerated plants showed that the exogenous gene sHSP had been integrated into genome of P. ternata.

[Differential display of mRNA from microtubers of Pinellia ternata in vitro].

OBJECTIVE: To study mRNA differential expression from microtubes of Pinellia ternata in vitro, and give more information of the molecular mechanism in the formation of microtubers. METHOD: DDRT-PCR was used to identify the expressed gene fragments related to the microtubers development of P. ternata in vitro. RESULTS AND CONCLUSION: Fifteen cDNA fragments differentially expressed in the induction of microtubers of P. ternata in vitro were identified and characterized by using mRNA differential display DDRT-PCR. The deduced amino-acid sequences of six fragments of cDNA showed no significant homology with ESTs and genes in the Genbank databases, and they could be new cDNA fragments. However, the remaining three showed significant homologies with sequences encoding components of eukaryotic translation initiation factor 3 subunit H, MADS-box protein and ethylene signal transcription factor, respectively. Their differential expression patterns were confirmed by semi-quantitative RT-PCR analysis. And the expression level of the induction of microtubers of P. ternata in vitro was different.

[Changes of total RNA and mRNA differential expressions in leaves of Pinellia ternata under high temperature stress].

OBJECTIVE: To study the total RNA and mRNA differential expression in leaves of Pinellia ternata under high temperature, provide more information of the molecular mechanism of the sprout tumble. METHOD: The total RNA and mRNA differential expression in leaves of P. ternata at different stress time was analyzed. RESULT: The results showed that the trend of total RNA content was divided into three descending stages and two ascending stages, the total RNA content was the highest at 0, 6 h, but it was the lowest at and 42 h, as well as when the sprout tumbled. The differential display showed that the polymorphism and type of bands of the sample at 6 h were similar to those at 0 h. But the bands numbers at other time were far less than those at 0, 6 h. And there were some different mRNA differential expression bands between the different samples. CONCLUSION: In the process of the sprout tumble caused by high temperature stress, the RNA and mRNA differential expression in leaves of P. ternata changed.

[Variation of endogenous hormones in formation of microtubers of Pinellia ternata in vitro].

OBJECTIVE: Through analysis of variation and function of five endogenous hormones (IAA, GA3, ABA, ZR and JA) in the formation of microtubers of Pinellia ternata in vitro to explore the physiological and biochemical mechanism of tubers' development. METHOD: The endogenous hormones of microtubers were isolated in different stages of tubers expansion when the leaf stalks of P. ternata were cultured on MS + 6-BA 0.5 mg x L(-1) + NAA 0.1 mg x L(-1) + sucrose 5% medium to induce the formation of microtubers, then them and stems were detected with Enzyme-linked Immunosorbent Assays (ELISA). RESULT: The results showed that the content of IAA, ABA, JA and ZR in the intumescentia period of microtubers were rapidly rising. The curve of GA3 appeared the type of anti-S. CONCLUSION: IAA, ABA, JA, ZR and GA3 played an important role in controlling formation of microtubers in P. ternata.

[Nutrient uptake characteristics of nitrogen, phosphorus and potassium of Pinellia ternate from Sichuan during growth stage].

OBJECTIVE: To study the absorption characteristics of nitrogen (N) , phosphorus (P) , and potassium (K) of Pinellia ternate from Sichuan under the cultivated condition. METHOD: The samples of P. ternate S-29 and S-33 from Sichuan were regularly collected randomly, the contents of nitrogen, phosphorus and potassium of each part (aerial and underground parts) were determined, and their distribution and accumulation characters of nitrogen, phosphorus, potassium were also studied. RESULT: The absorption rate of aerial and underground parts of P. ternate were different in nitrogen, phosphorus, and potassium at different growing stages. Among them, the potassium uptake was the highest, while the phosphorus uptake was the lowest. Totally, the uptakes of nitrogen, phosphorus and potassium of P. ternate from Sichuan during "sprout tumble" stage were comparatively higher than that not at "sprout tumble" stage. A significant correlation was observed between the phosphorus and potassium uptake of the aerial and underground parts, respectively (P < 0.05). And there was also significant positive correlation between the nitrogen and phosphorus uptake at underground parts (P < 0.05). During the growth stage of P. ternate, for producing 100 kg air-dried P. ternate, 5.02-5.64 kg N, 2.44-2.56 kg P205, 11.62-13.49 kg K20 were needed to be absorbed. CONCLUSION: P. ternate from Sichuan should be given enough base fertilizer in field cultivation, and then be supplied with phosphorus and potassium by combining foliar spray with field application during the middle ten days of June and last ten days of August. The ratios of potassium should be properly improved. There was promoting effect in the phosphorus and nitrogen assimilations of the underground parts of P. ternate from Sichuan.