Chinese Cabbage Leaf Research Articles

Geraniol의 채소 작물 유근생장 및 배추 생장 촉진효과

This study investigated the plant growth promoting activity of geraniol on Chinese cabbage (Brasscia campestris ssp. Pekinensis Rupr.), Pak Choi (Brassica rapa L.), Crown daisy (Chrysanthemum coronarium L.), Iceberg lettuce (Lactuca sativa L.) and Leaf perilla (Perilla frutescens Britt.). Geraniol at 0.5 to promoted radical growth of Chinese cabbage Pak Choi, Crown daisy, Iceberg lettuce and leaf perilla by >30%. In the pot experiments, geraniol treatment at by drenching increased up to 190% of the aerial part growth promotion. By comparison, foliar application showed 124% promoting activity only at .

Leaf and root glucosinolate profiles of Chinese cabbage (Brassica rapa ssp. pekinensis) as a systemic response to methyl jasmonate and salicylic acid elicitation.

Glucosinolates (GSs) are an important group of defensive phytochemicals mainly found in Brassicaceae. Plant hormones jasmonic acid (JA) and salicylic acid (SA) are major regulators of plant response to pathogen attack. However, there is little information about the interactive effect of both elicitors on inducing GS biosynthesis in Chinese cabbage (Brassica rapa ssp. pekinensis). In this study, we applied different concentrations of methyl jasmonate (MeJA) and/or SA onto the leaf and root of Chinese cabbage to investigate the time-course interactive profiles of GSs. Regardless of the site of the elicitation and the concentrations of the elicitors, the roots accumulated much more GSs and were more sensitive and more rapidly responsive to the elicitors than leaves. Irrespective of the elicitation site, MeJA had a greater inducing and longer lasting effect on GS accumulation than SA. All three components of indole GS (IGS) were detected along with aliphatic and aromatic GSs. However, IGS was a major component of total GSs that accumulated rapidly in both root and leaf tissues in response to MeJA and SA elicitation. Neoglucobrassicin (neoGBC) did not respond to SA but to MeJA in leaf tissue, while it responded to both SA and MeJA in root tissue. Conversion of glucobrassicin (GBC) to neoGBC occurred at a steady rate over 3 d of elicitation. Increased accumulation of 4-methoxy glucobrassicin (4-MGBC) occurred only in the root irrespective of the type of elicitors and the site of elicitation. Thus, accumulation of IGS is a major metabolic hallmark of SA- and MeJA-mediated systemic response systems. SA exerted an antagonistic effect on the MeJA-induced root GSs irrespective of the site of elicitation. However, SA showed synergistic and antagonistic effects on the MeJA-induced leaf GSs when roots and leaves are elicitated for 3 d, respectively.

Global analysis of transcriptional response of Chinese cabbage to methyl jasmonate reveals JA signaling on enhancement of secondary metabolism pathways

Methyl jasmonate (MeJA) is known to increase multiple resistance and secondary metabolism pathways in Brassicaceae (Cruciferae). However, the mechanisms of regulation at the transcriptomic level were not well studied. So, we conducted a RNA-Seq analysis of MeJA-treated Chinese cabbage leaf transcriptome. Among 27,461 detected genes, 1451 genes were up-regulated and 991 genes were down-regulated as differentially expressed genes (DEGs) (log2 of the fold change in gene expression ≥1, false discovery rate ≤0.001). More than 90% of the DEGs were between 2.0- and 8.0-fold changes. The most highly represented pathways by 1674 annotated DEGs were related to “metabolic pathways” (333 members). Fourteen genes involved in JA biosynthesis pathway were up-regulated. Forty genes for glucosinolate biosynthesis were induced, and the level of indole glucosinolate was highly increased by MeJA treatment. Several selected genes involved in JA signaling and indole glucosinolate synthesis pathways were validated by quantitative RT-PCR. The results expand our understanding of the complex molecular events on JA-induced plant resistance and accumulation of secondary metabolites.

Erratum to: Loss of Function of the Carotenoid Isomerase Gene BrCRTISO Confers Orange Color to the Inner Leaves of Chinese Cabbage (Brassica rapa L. ssp. pekinensis)

Erratum to: Loss of Function of the Carotenoid Isomerase Gene BrCRTISO Confers Orange Color to the Inner Leaves of Chinese Cabbage (Brassica rapa L. ssp. pekinensis)

Loss of Function of the Carotenoid Isomerase Gene BrCRTISO Confers Orange Color to the Inner Leaves of Chinese Cabbage (Brassica rapa L. ssp. pekinensis)

Chinese cabbage varieties with orange inner leaves are of interest due to their attractive appearance and high carotenoid content. Previously, a recessive locus, Br-or, that confers this trait was mapped to linkage group A09 in Brassica rapa, and Bra031539 was identified as the candidate gene. We used a backcross population consisting of 1,392 individuals for fine mapping; three linked markers delimited the Br-or locus to a region of 9.47 kb, which contained only one predicted functional gene, Bra031539 (the carotenoid isomerase gene BrCRTISO). We identified two bacterial artificial chromosome (BAC) clones carrying Br-or and confirmed that this allele of BrCRTISO confers the mutant phenotype by sequencing. Many DNA sequence variations are present in Br-or, including a 90-bp DNA deletion in the promoter and a 501-bp insertion at the 3′ end of the gene. GUS staining showed that the spatial expression of BrCRTISO was perfectly coincident with the site of carotenoid synthesis and that the 90-bp deletion in the promoter slightly downregulated expression of the gene. Using an in vitro enzyme assay, we showed that the mutant Br-or protein cannot convert prolycopene to all-trans-lycopene. Light has a positive effect on the expression of carotenoid biosynthesis genes, except for beta-ring carotene hydroxylase (CHXB), and this coincided with the increase in total lycopene and β-carotene in the Br-or mutant. We also demonstrated that loss of BrCRTISO function, upregulation of the upstream genes, and downregulation of downstream genes lead to the accumulation of prolycopene and confer an orange color to the inner head leaves in Chinese cabbage.

Accumulation of heavy metals in leaf vegetables from agricultural soils and associated potential health risks in the Pearl River Delta, South China.

This study investigated the extent of heavy metal accumulation in leaf vegetables and associated potential health risks in agricultural areas of the Pearl River Delta (PRD), South China. Total concentrations of mercury (Hg), cadmium (Cd), lead (Pb), chromium (Cr) and arsenic (As) were determined in 92 pairs of soil and leaf vegetable (flowering Chinese cabbage, lettuce, pakchoi, Chinese cabbage, loose-leaf lettuce, and Chinese leaf mustard) samples collected from seven agricultural areas (cities). The bioconcentration factors (BCF) of heavy metals from soil to vegetables were estimated, and the potential health risks of heavy metal exposure to the PRD residents through consumption of local leaf vegetables were assessed. Results showed that among the six leaf vegetables, pakchoi had the lowest capacity for heavy metal enrichment, whereas among the five heavy metals, Cd had the highest capacity for transferring from soil into vegetables, with BCF values 30-fold those of Hg and 50-fold those of Cr, Pb and As. Sewage irrigation and fertilization were likely the main sources of heavy metals accumulated in leaf vegetables grown in agricultural areas of the PRD region. Different from previous findings, soil pH had no clear effect on metal accumulation in leaf vegetables. Despite a certain degree of metal enrichment from soil to leaf vegetables, the PRD residents were not exposed to significant health risks associated with consumption of local leaf vegetables. Nevertheless, more attention should be paid to children due to their sensitivity to metal pollutants.

Plant traits and quality evaluation of different cultivation forms of Isatis

To lay a foundation for the study on good variety selection of Isatis indigotica, comparison of plant traits and quality evaluation of Isatis germplasm resources from different production area was conducted. Field cultivation and randomized block experiment were adopted to compare those plant traits of leaf, root, silique and seed of Isatis from different production area and the content of R,S-goitrin and polysaccharide in the root was determined. Different cultivation forms of Isatis had significant difference from each other in leaf, root, silique and seed, content of R,S-goitrin and polysaccharide in the root were also different. R,S-goitrin content in Isatis of Chinese cabbage leaf type ( production area: Yunnan ) was comparative higher, 0.59% , while polysaccharide content in autotetraploid Isatis was comparative higher, 8.68%. According to the plant traits, Isatis were classified into three types: Chinese cabbage leaf type, cabbage leaf type and mustard leaf type, of which R,S-goitrin content in Chinese cabbage leaf type (production area: Yunnan) was comparative higher, while polysaccharide content in autotetraploid Isatis was comparative higher.

Evaluation of insecticidal activity of a bacterial strain, Serratia sp. EML-SE1 against diamondback moth

To identify novel bioinsecticidal agents, a bacterial strain, Serratia sp. EML-SE1, was isolated from a dead larva of the lepidopteran diamondback moth (Plutella xylostella) collected from a cabbage field in Korea. In this study, the insecticidal activity of liquid cultures in Luria-Bertani broth (LBB) and nutrient broth (NB) of a bacterial strain, Serratia sp. EML-SE1 against thirty 3rd and 4th instar larvae of the diamondback moth was investigated on a Chinese cabbage leaf housed in a round plastic cage (Ø 10 x 6 cm). 72 h after spraying the cabbage leaf with LBB and NB cultures containing the bacterial strain, the mortalities of the larvae were determined to be 91.7% and 88.3%, respectively. In addition, the insecticidal activity on potted cabbage containing 14 leaves in a growth cage (165 x 83 x 124 cm) was found to be similar to that of the plastic cage experiment. The results of this study provided valuable information on the insecticidal activity of the liquid culture of a Serratia species against the diamondback moth.

Sodium nitroprusside mediates seedling development and attenuation of oxidative stresses in Chinese cabbage

Nitric oxide (NO) has been shown to be involved in diverse physiological processes in microbes, animals and plants. In this study, the involvement of NO in the development and possible roles in oxidative stress protection of Chinese cabbage (Brassica rapa subsp. pekinensis cv. Samrack-ulgari) seedlings were investigated. Exogenous application of sodium nitroprusside (SNP) retarded root elongation, while increasing lateral root formation of Chinese cabbage. Plants showed no signs of external stress due to SNP application in true leaves. Cotyledons of 3-week-old Chinese cabbage plants were found to be highly sensitive to SNP application. Treated cotyledons displayed rapid tissue collapse and associated cell death. Although SNP application reduced root growth under normal growth conditions, it also enhanced methyl viologen (MV)-mediated oxidative stress tolerance. Analysis of SNP application to Chinese cabbage leaf disks, revealed SNP-induced tolerance against oxidative stresses by MV and H2O2, and evidence includes prevention of chlorophyll loss, superoxide anion (O2 −) accumulation and lipid peroxidation. This report supports a role for nitric oxide in modulating early seedling development, programmed cell death and stress tolerance in Chinese cabbage.

Mechanisms of partial plant resistance to diamondback moth (Plutella xylostella) in brassicas

Artificial diet studies were used to differentiate among physical and chemical mechanisms affecting the suitability to diamondback moth (Plutella xylostella L.), of 16 food substrates obtained by growing four different brassicas in the glasshouse or field and measuring the pest's performance on either leaf discs or a diet incorporating leaf powders. Leaves of Chinese cabbage and the cabbage cultivar ‘Minicole’ were, respectively, the most and least suitable leaves for the insect, but this ranking was reversed on artificial diet. Leaves of glasshouse-grown plants were more suitable than those of plants grown in the fields. Differences in the suitability of leaves to diamondback moth appeared to be largely determined by leaf toughness and surface wax load. Concentrations of individual glucosinolates in the brassicas probably acted as phagostimulants, so increasing their intrinsic susceptibility to diamondback moth, but the effect of the physical factors appeared more important.

High-frequency adventitious shoots regeneration from leaf of non-heading Chinese cabbage (Brassica campestris ssp. chinensis) cultured in vitro

The objective of the present work was selection of cultivar and suitable medium for regenerating shoots from leaf segments of non-heading Chinese cabbage. We evaluated six types of supplemented media with 2.0, 5.0 and 10.0 mg l−1 6-BA; 1.0 and 2.0 mg l−1 TDZ; 0.1, 0.3, 0.5, 0.8 and 1.0 mg l−1NAA; 3.0, 5.0 and 7.5 mg l−1AgNO3; 0.01 mg l−1 2–4, D and 4.0 mg l−1 KT for shoot regeneration and six cultivars “Sanchidaye”, “Liuchuandasuomian”, “Qingyou 4”, “Liangbaiye”, “AiKang 5” and “Hanxiao F3”, furthermore for root formation three types of supplemented media with 0.2, 0.3, 0.5 mg l−1 NAA, and for survival rate two types of base media: turf + vermiculite + manure (1:2:0.2) and soil + vermiculite (1:2). Culturing leaf segments on MS medium supplemented with 2 mg l−1 TDZ; 0.5 mg l−1 NAA and 7.5 mg l−1 AgNO3 gave the highest number of shoots per leaf segment (66) while roots were best formed on the medium supplemented with 0.2 mg l−1 NAA. Survival rate was highest (61.6%) in the turf: vermiculite: manure (1:2:0.2) medium. The highest percentage of responding leaf segments, number of shoots per leaf segment, rooting percentage and survival rate were observed in “Liuchuandasuomian”. The plantlets were transferred to the soil and grown into mature plants in pots. These results could be used for preliminary selections of cultivars to transfer disease resistance (Bt) gene through agrobacterium in non-heading Chinese cabbage.

Direct Determination of Atrazine Residue on Chinese Cabbage Leaf Using Desorption Electrospray Ionization-Tandem Mass Spectrometry and Its Application for Diagnosing Atrazine Drift Phytotoxicity

A method was developed for the determination of atrazine residue and phytotoxicity on a nontargeted plant, the Chinese cabbage. The analysis was done by desorption electrospray ionization combined with ion trap MS/MS. Within the range of 63.13 to 2525 pg/mm2 of atrazine on the specimen, the linear relationship of the average peak area of extracted product ion m/z 174 (y) versus the surface concentration of atrazine (x) was estimated as y = 5066.5x - 85779; r was 0.9994, with RSD between 3.37 and 26.17%. The LOQ of atrazine on the leaf surface was lower than 63.13 pg/mm2. The method is highly applicable to detect atrazine residue and evaluate atrazine phytotoxicity on Chinese cabbage leaf with good accuracy, selectivity, sensitivity, and specificity.

Efeito de extratos de plantas com atividade inseticida no controle de Microtheca ochroloma Stal (Col.: Chrysomelidae), em laboratório

Effect of extracts of plants with insecticidal activity on the control of Microtheca ochroloma Stal (Col: Chrysomelidae) in the laboratory. Extracts of plants with insecticidal activity were tested on the control of Microtheca ochroloma (Col.: Chrysomelidae), an important insect-pest of Brassica- ceae, in the larval and adult phases. Two 3-day-old larvae, kept under laboratory conditions (25 ºC temperature, 70% relative humidity and 14 hours of photophase), were placed in a glass tube with a leaf of Chinese cabbage (Brassica chinensis) previously treated with aqueous extracts (10% p/v) of chinaberry leaf (Melia azedarach), chinaberry branch, and tobacco powder (Nicotiana tabacum). The same procedure was repeated in two assays with adult insects. In the fi rst assay, all the previously mentio ned extracts were used, in addition to DalNeem (commercial product of Azadirachta indica). In the second, the insects were exposed to extracts of tabasco pepper fruits (Capsicum frutes- cens), Surinam cherry (Eugenia unifl ora), jambolan (Syzygium cuminii) and eucalyptus leaves (Eucalyptus sp.). All the tests consisted of 10 insects per treatment, with fi ve repetitions in the fi rst test using adult insects and six repetitions in the others. Observations were made daily up to the fi fth day, aiming to evaluate the mortality of the insects. All the tested extracts resulted in an effective control of the larvae of M.ochro- loma. In relation to the adult insects, only the extracts of tobacco powder and DalNeem showed effective control.

Purification and Characterization of an Antifungal Protein, C-FKBP, from Chinese Cabbage

An antifungal protein was isolated from Chinese cabbage (Brassica campestris L. ssp. pekinensis) by buffer-soluble extraction and two chromatographic procedures. The results of matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry revealed that the isolated Chinese cabbage protein was identical to human FK506-binding protein (FKBP). A cDNA encoding FKBP was isolated from a Chinese cabbage leaf cDNA library and named C-FKBP. The open reading frame of the gene encoded a 154-amino acid polypeptide. The amino acid sequence of C-FKBP exhibits striking degrees of identity with the corresponding mouse (61%), human (60%), and yeast (56%) proteins. Genomic Southern blot analyses using the full-length C-FKBP cDNA probe revealed a multigene family in the Chinese cabbage genome. The C-FKBP mRNA was highly expressed in vegetative tissues. We also analyzed the antifungal and peptidyl-prolyl cis-trans isomerase activity of recombinant C-FKBP protein expressed in Escherichia coli. This protein inhibited pathogenic fungal strains, including Candida albicans, Botrytis cinerea, Rhizoctonia solani, and Trichoderma viride, whereas it exhibited no activity against E. coli and Staphylococcus aureus. These results suggest that recombinant C-FKBP is an excellent candidate as a lead compound for the development of antifungal agents.

복숭아혹진딧물 방제를 위한 Lecanicillium 균주 선발

본 연구는 채소류 생산 농가에서 막대한 피해를 주고 있는 해충인 진딧물에 대한 방제효과가 우수한 환경친화적 살충성 미생물 개발을 위한 기초연구로서 살충효과를 갖는 Lecanicilium(Verticillium)속의 우수 균주를 선발하고, 포자생산을 위한 배지를 선정하며, 분자 동정법을 확립하여 새로운 균주 탐색을 위한 기틀을 마련하고자 실시하였다. 새로 동정된 Lecanicillium속 5균주를 이용하여 복숭아혹진딧물(Myzus persicae)에 살충력 시험과 균주들의 여러 특성들을 조사한 결과, 4078 균주는 실온과 <TEX>$30^{\circ}C$</TEX>에서 우수한 살충력을 나타냈으며, <TEX>$30^{\circ}C$</TEX>에서 2일 만에 100%의 살충성을 보였다. 한편, 낮은 상대 습도에서 가장 우수한 균주는 RH 85%에서 5일 동안 90%의 살충성을 보인 6543 균주이었다. 이들 4078과 6543균주들의 ITS의 DNA 염기서열(accession no.: 순서대로 EF026004와 EF026005)에 의해 Lecanicillium 종으로 확인되었다. 한편, 미생물 농약 생산에 중요한 포자 생산에 있어서 6543 균주가 4078 균주보다 월등히 우수하였는데, 6543 균주의 살충력이 4078 균주보다는 다소 낮지만, 살충력이 여전히 우수하며 포자생산량이 많고, 회수에도 용이하기 때문에, 미생물농약으로서는 6543 균주가 가장 적합하다고 판단된다. To select efficient entomopathogenic fungal strains of Lecanicillium for the biocontrol of aphid, Myzus persicae, conidial suspension (<TEX>$1{\times}10\;conidia/ml$</TEX>) was sprayed onto a detached Chinese cabbage leaf in a petri dish with a dampened filter paper that had 20 nymphs of aphid. Lecancillium strain 4078 and 6543 were the best strains for the biocontrol of aphid at high temperature of <TEX>$30^{\circ}C$</TEX> and low relative humidity (RH) of 85%, respectively. The cumulative mortality of strain 4078 at <TEX>$30^{\circ}C$</TEX> after 3 days was 100% and that of strain 6543 was 90% at 85% RH after 5 days. Strain 4078 also exhibited almost 100% germination ratio of conidia and high rate of mycelial growth at the broad temperature-range of <TEX>$15{\sim}25^{\circ}C$</TEX>. The strain 4078 and 6543 were all identified as Lecanicillium species based on the DNA sequences (accession no.: EF026004 and EF026005, respectively) of the ITS regions of the fungi. Excellent production of aerial conidia of strain 6543 was accomplished by using steamed polished rice as the solid culture medium.

Molecular and functional characterization of a cyclophilin with antifungal activity from Chinese cabbage

An antifungal protein that inhibits the growth of filamentous fungal pathogens was isolated from Chinese cabbage ( Brassica campestris L. ssp. pekinensis) by affinity chromatography on Affi-gel blue gel and ion exchange chromatography on CM-Sepharose. The N-terminal amino acid sequence of the protein was highly homologous to that of plant cyclophilins and consequently the protein was denoted as C-CyP. To understand the antifungal activity of C-CyP, we isolated a cDNA encoding its gene from a Chinese cabbage leaf cDNA library. The Chinese cabbage genome bears more than one C-CyP gene copy and C-CyP mRNA is highly expressed in all tissues except the seeds. Recombinant C-CyP catalyzed the cis– trans inter-conversion of the Ala–Pro bond of the substrate, which indicates this protein has peptidyl-prolyl cis– trans isomerase activity. It also inhibited the growth of several fungal pathogens.

The Expression of a Cytosolic Fructose-1,6-Bisphosphatase, a Key Enzyme in Sucrose Biosynthesis, Gene was Diurnally Fluctuated and Increased in Cold Acclimated Leaves of Chinese Cabbage

Chinese cabbage (Brassica rapa ssp. pekinesis) is one of the most important vegetable crops in korea and other East Asian countries. Cytosolic fructose-1,6-bisphospha-tase (cytFBPase) is a key enzyme in sucrose biosyn-thesis, which controls the sucrose levels as well as the productivity at plants. The Chinese cabbage cytFBPase gene, BrFBPase, encodes the 340 amino acid polypep-tide, giving a theoretical molecular weight of 37.2 kD and a isolectric point of 5.4. BrFBPase showed high sequence identity with Brassica homologs and its functional domains, such as 12,6P binding site or active site and F6P binding site, were highly conserved in diverse sources of organisms. Although the genome of Chinese cabbage seemed to be triplicated, BrFBPase appears to be a single copy gene. The expression of BrFBPase was examined at transcript and protein levels under various conditions. BrFBPase expression was observed only in photosynthetic source tissue, not in sink tissue. The expression was slightly higher during the day than at night, and it showed a diurnal cycle with circadian rhythmicity. Short-term exposure to low temperature inhibited the expression of the BrFBPase, while long-term exposure increased the expression, supporting that sugar levels are high in late autumn when temperature are low.

EST analysis of the heading leaf of Chinese cabbage (Brassica rapa L. ssp. pekinensis) in the early phase of the heading stage

AbstractA cDNA library was constructed from the heading leaf in the early phase of the heading stage of Chinese cabbage (Brassica rapa L. ssp. pekinensis). By sequencing the randomly selected clones, 1363 sequences longer than 200 bp were found, with better trace data. After removing the poly(A) and contamination sequences, 1162 ESTs longer than 150 bp were obtained, of which 1102 shared significant similarity with known sequences in protein and nucleotide databases of the National Center for Biotechnology Information (NCBI) as revealed by searches using the BLASTX and BLASTN engines. Functional assignment of the ESTs was based on the method used in the Arabidopsis thaliana genome-sequencing project. About 77% of the putative protein sequences with known biological functions best matched with those of A. thaliana deposited in the non-redundant database of NCBI. These data suggest that Chinese cabbage is closely related to A. thaliana. This result is different from that reported in other Brassica species. At nucleotide level, however, 51% of the ESTs were homologous to those deposited for A. thaliana when all ESTs were searched against the est-others database. In addition, 60 ESTs had no homology with any of the plant gene sequences deposited in GenBank. These ESTs are very important for understanding the unique developmental process of Chinesecabbage and elaborating its genetic mapping. Among the genes with assigned functions, the most abundant representatives were those involved in protein synthesis and energy metabolism. With the 1162 ESTs, 895 non-redundant contigs were generated after being aligned using the Seqman II module of DNAStar software at the threshold of more than 80% homology over a minimum of 40 base pairs. Of these, 723 were singletons containing only one EST sequence, indicating that many kinds of such genes are expressed in the heading leaf of Chinese cabbage. An expression profile of Chinese cabbage heading leaf with the 1162 ESTs was therefore acquired in this work. This could be very useful for uncovering the mechanism of the heading process, which is the most obvious characteristic of Chinese cabbage and perhaps other related species, such as Brassica oleracea. This work could accelerate the finding and characterization of genes specifically expressed in the heading stage of Chinese cabbage.

Biocontrol of Pythium tracheiphilum in Chinese Cabbage by Clonostachys rosea under Field Conditions

Control of leaf and head rot of Chinese cabbage (Brassica campestris L. ssp. pekinensis), caused by Pythium tracheiphilum, was obtained by Clonostachys rosea (isolate IK726) in field trials conducted in 1995 and 1999 on naturally infested land in a commercial crop in Denmark. A significant 2-3-fold disease reduction was obtained at an application rate of 108-109 conidia m−2 (high application rate) in both years, but not at a 10-fold reduced rate in 1999. Disease reduction by Trichoderma harzianum (Supresivit) was almost significant at the high application rate (1 g product m−2 corresponding to 7×109 colony forming units (CFUs) m−2) in both years, but not at a 10-fold reduced rate applied in 1999. In both 1995 and 1999 trials, the percentage of marketable heads increased significantly by 10% following a full application rate of C. rosea. Supresivit applied at the full application rate gave a significant 13% yield improvement in 1995 but not in 1999. No yield improvement was found when the two agents were applied at 10-fold reduced rates. A Danish T. harzianum isolate significantly increased yield by 13% in 1995, but gave no disease control. Plant growth promotion may have been responsible for yield improvements obtained by Supresivit and the Danish isolate of T. harzianum. The 1995 trial also evaluated the products Binab T (T. harzianum+T. polysporum), Mycostop (Streptomyces griseoviridis), Polyversum (P. oligandrum) and Aliette (fosetyl-Al) and Danish isolates of P. oligandrum (2) and T. virens (1), none of which gave disease control or yield effects.

Cloning and structural and expressional characterization of BcpLH gene preferentially expressed in folding leaf of Chinese cabbage

Vegetative growth of Chinese cabbage undergoes the four successive stages which are characterized with the definite types of juvenile, rosette, folding and head leaves. From shoot tips of Chinese cabbage at early folding stage, we constructed a cDNA library and screened the differentially expressed cDNA clones using the cDNAs derived from developing folding leaves and rosette leaves as probes. One complete length of cDNA clone is designated asBcpLH. Computer alignment matched BcpLH to the domains of double-stranded RNA binding (DBRM) and the homologous regions were recognized between BcpLH and human and mouse double-stranded RNA-binding protein TRBP. PCR expression analysis shows that during vegetative growthBcpLH gene was expressed preferentially in folding leaves at folding stage. Transcripts ofBcpLH gene were increased when plants were sprayed with IAA. It is deduced thatBcpLH gene may be related to initiation of folding leaf and leafy head and induced by auxin in the aspect of transcriptional expression.