Transcriptomic analysis provides insight into defensive strategies in response to continuous cropping in strawberry (Fragaria × ananassa Duch.) plants.

BACKGROUND: Strawberries are an important economic fruit crop world-wide. In strawberry cultivation, continuous cropping (CC) can seriously threaten yield and quality. However, our understanding of the gene expression changes in response to CC and during subsequent defense processes is limited. In this study, we analyzed the impact of CC on the transcriptome of strawberry roots using RNA-Seq technology to elucidate the effect of CC and the subsequent molecular changes. RESULTS: We found that CC significantly affects the growth of strawberry plants. The transcriptome analysis identified 136 differentially expressed genes (DEGs), including 49 up-regulated and 87 down-regulated DEGs. A Gene Ontology (GO) analysis indicated that the up-regulated DEGs were mainly assigned to defense-related GO terms, and most down-regulated DEGs were assigned to nutrient-related GO terms. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that the responsive DEGs were classified in a large number of important biological pathways, such as phenylalanine metabolism, starch and sucrose metabolism, phenylpropanoid biosynthesis, glutathione metabolism and plant-pathogen interaction. We also found that four WRKY transcription factors and three peroxidase genes involved in plant defense pathways were up-regulated in the roots of strawberry plants subjected to CC. CONCLUSION: Several unigenes involved in plant defense processes, such as CNGCs, WRKY transcription factors, PR1, and peroxidase genes with highly variable expression levels between non-CC and CC treatments may be involved in the regulation of CC in strawberry. These results indicate that strawberry roots reallocate development resources to defense mechanisms in response to CC. This study will further deepen our understanding of the fundamental regulatory mechanisms of strawberry resource reallocation in response to CC.

Transcriptomic analysis reveals recovery strategies in strawberry roots after using a soil amendment in continuous cropping soil.

BACKGROUND: In strawberry cultivation, continuous cropping (CC) obstacles seriously threaten production. A patented soil amendment (SA) can effectively relieve the CC obstacles to strawberry cultivation, but knowledge of the recovery mechanisms underlying this phenomenon is limited. RESULTS: In this study, transcriptomic profiling of strawberry roots in soil with and without the SA was conducted using RNA-Seq technology to reveal gene expression changes in response to SA treatment. In total, 188 differentially expressed genes (DEGs), including 144 upregulated and 44 downregulated DEGs, were identified. SA treatment resulted in genotype-dependent responses, and the response pattern, including an overall increase in the expression of nutrient transport genes and a decrease in the expression of defense response genes, may be a possible mechanism underlying recovery strategies in strawberry roots after the application of the SA to CC soil. We also found that 9 Hsp genes involved in plant defense pathways were all downregulated in the SA-treated roots. CONCLUSIONS: This research indicated that strawberry plants reallocated defense resources to development when SA treatment alleviated the stress caused by a CC soil environment. The present study provides an opportunity to reveal the fundamental mechanisms of the tradeoff between growth and defense in strawberry.

[Effect of acupoint massage dominant early comprehensive intervention on the prognosis of premature infants with brain injury].

OBJECTIVE: To explore the effect of acupoint massage dominant early comprehensive intervention on the prognosis of premature infants with brain injury. METHODS: Totally 210 premature infants with brain injury were assigned to the intervention group (112 cases) and the control group (98 cases). All patients received routine therapy (medicinal + routine care instructions). Patients in the intervention group additionally received acupoint massage. Those with abnormal early motion received physical sports treatment. Those with upper limbs dysfunction or with fine movement disorders received occupational therapy. Premature infants' development quotient (DQ) was performed at corrected age of 6 and 12 months by using neuropsychological development examination table for 0 - 6 years old children. The incidence of cerebral palsy was statistically calculated. RESULTS: At corrected age of 6 months, DQ of gross motor, fine motor, language three functional areas was higher in the intervention group than in the control group with significant difference (P < 0.05). At corrected age of 12 months, DQ of gross motor, fine motor, language, social and adaptive capacities was higher in the intervention group than in the control groupwith significant difference (P < 0.05). The incidence of cerebral palsy was 4.46% (5/112) in the intervention group and 12.24% (12/98) in the control group (P < 0.05). CONCLUSION: Acupoint massage dominant early comprehensive intervention could obviously improve the intelligence development level and lower the incidence of cerebral palsy in premature infants with brain injury.

Identification of repellent and insecticidal constituents of the essential oil of Artemisia rupestris L. aerial parts against Liposcelis bostrychophila Badonnel.

The aim of this research was to determine the chemical composition and insecticidal and repellent activity of the essential oil of Artemisia rupestris L. aerial parts against the booklice Liposcelis bostrychophila Badonnel and isolation of insecticidal and repellent constituents from the essential oil. The essential oil of A. rupestris was obtained by hydrodistillation and analyzed by GC-MS. A total of 30 components of the essential oil of A. rupestris was identified and the principal compounds in the essential oil were α-terpinyl acetate (37.18%), spathulenol (10.65%), α-terpineol (10.09%), and linalool (7.56%), followed by 4-terpineol (3.92%) and patchoulol (3.05%). Based on bioactivity-guided fractionation, the four active constituents were isolated from the essential oil and identified as α-terpineol, α-terpinyl acetate, 4-terpineol and linalool. The essential oil of A. rupestris exhibited contact toxicity against L. bostrychophila with LD50 value of 414.48 µg/cm². α-Terpinyl acetate (LD50 = 92.59 µg/cm²) exhibited stronger contact toxicity against booklice than α-terpineol (LD50 = 140.30 µg/cm²), 4-terpineol (LD50 = 211.35 µg/cm²), and linalool (LD550 = 393.16 µg/cm²). The essential oil of A. rupestris (LC50 = 6.67 mg/L air) also possessed fumigant toxicity against L. bostrychophila while the four constituents, 4-terpineol, α-terpineol, α-terpinyl acetate and linalool had LC50 values of 0.34, 1.12, 1.26 and 1.96 mg/L air, respectively. α-Terpinol and α-terpinyl acetate showed strong repellency against L. bostrychophila, while linalool and 4-terpinol exhibited weak repellency. The results indicate that the essential oil of A. rupestris aerial parts and its constituent compounds have potential for development into natural insecticides or fumigants as well as repellents for control of insects in stored grains.

Chemical composition and nematicidal activity of essential oil of Agastache rugosa against Meloidogyne incognita.

The aim of this research was to determine the chemical composition and nematicidal activity of essential oil of Agastache rugosa flowering aerial parts against the root knot nematode, Meloidogyne incognita, and to isolate and identify any nematicidal constituents from the essential oil. The essential oil of A. rugosa aerial parts was obtained by hydrodistillation and analyzed by GC-FID and GC-MS. A total of 37 components of the essential oil were identified, with the principal compounds being methyleugenol (50.51%), estragole (8.55%), and eugenol (7.54%), followed by thymol (3.62%), pulegone (2.56%), limonene (2.49%) and caryophyllene (2.38%). Based on bioactivity-guided fractionation, the three active constituents were isolated from the essential oil and identified as methyleugenol, estragole and eugenol. The essential oil of A. rugosa exhibited strong nematicidal activity against M. incognita, with a LC50 value of 47.3 µg/mL. The components eugenol (LC50 = 66.6 µg/mL) and methyleugenol (LC50 = 89.4 µg/mL) exhibited stronger nematicidal activity against M. incognita (LC50 = 185.9 µg/mL). The results indicate that the essential oil of A. rugosa aerial parts and its constituent compounds have potential for development into natural nematicides for control of the root knot nematode.

[Effect of several physiochemical factors on cell growth and isoflavone accumulation of Pueraria lobata cell suspension culture].

OBJECTIVE: To illustrate the effects of several physiochemical factors on cell growth and isoflavone accumulation of Pueraria lobata cell suspension cultures. METHOD: High performance liquid chromatography and plant tissue culture were applied. RESULT AND CONCLUSION: Cell growth and isoflavone accumulation were significantly stimulated in P. lobata cell suspension cultures by the increase of the sucrose concentration. Maintaining the pH value at the range over 5. 4 to 5. 8 was most suitable for isoflavone accumulation in P. lobata cell suspension cultures. Cell dried weight and isoflavone accumulation decreased sharply with the increase of the treated concentration of active carbon, while XAD-4 significantly stimulated cell growth and isoflavone accumulation.